CINXE.COM

<!DOCTYPE html> <html lang="en-US"> <head > <meta charset="UTF-8" /> <meta name="viewport" content="width=device-width, initial-scale=1" /> <meta property="fb:admins" content="1140409510" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta property="fb:admins" content="107031532675062" /> <meta name="msvalidate.01" content="40BA1B879066C83CDFCA374CA4B490C3" /> <meta name='robots' content='index, follow, max-image-preview:large, max-snippet:-1, max-video-preview:-1' /> <style>img:is([sizes="auto" i], [sizes^="auto," i]) { contain-intrinsic-size: 3000px 1500px }</style>  <title>Build an Alcohol Detection Engine Lock System</title> <meta name="description" content="The MQ3 alcohol gas sensor detects the alcohol and passes a signal to Arduino, which locks a vehicle's engine with the help of a relay." /> <link rel="canonical" href="https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/" /> <meta property="og:locale" content="en_US" /> <meta property="og:type" content="article" /> <meta property="og:title" content="How to build an alcohol detector with the MQ3 gas sensor" /> <meta property="og:description" content="The MQ3 alcohol gas sensor detects the alcohol and passes a signal to Arduino, which locks a vehicle's engine with the help of a relay." /> <meta property="og:url" content="https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/" /> <meta property="og:site_name" content="Engineers Garage" /> <meta property="article:publisher" content="https://www.facebook.com/engineersgarage" /> <meta property="og:image" content="https://www.engineersgarage.com/wp-content/uploads/2024/06/Demo2-rotator.png" /> <meta property="og:image:width" content="800" /> <meta property="og:image:height" content="507" /> <meta property="og:image:type" content="image/png" /> <meta name="author" content="Ayush Jain" /> <meta name="twitter:card" content="summary_large_image" /> <meta name="twitter:creator" content="@EngineersGarage" /> <meta name="twitter:site" content="@EngineersGarage" /> <meta name="twitter:label1" content="Written by" /> <meta name="twitter:data1" content="Ayush Jain" /> <meta name="twitter:label2" content="Est. reading time" /> <meta name="twitter:data2" content="4 minutes" /> <script type="application/ld+json" class="yoast-schema-graph">{"@context":"https://schema.org","@graph":[{"@type":"Article","@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#article","isPartOf":{"@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/"},"author":{"name":"Ayush Jain","@id":"https://www.engineersgarage.com/#/schema/person/f5e457ba68d983ca6ce696db9b2304b9"},"headline":"How to build an alcohol detector with the MQ3 gas sensor","datePublished":"2024-06-26T03:50:05+00:00","mainEntityOfPage":{"@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/"},"wordCount":553,"commentCount":0,"publisher":{"@id":"https://www.engineersgarage.com/#organization"},"image":{"@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#primaryimage"},"thumbnailUrl":"https://www.engineersgarage.com/wp-content/uploads/2024/06/Demo2-rotator.png","keywords":["accidents","alcoholdetector","Arduino","arduinouno","circuit","circuitdesign","mq3sensor","roadaccidents","safedriving","sensor"],"articleSection":["Circuit Design","Video"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#respond"]}]},{"@type":"WebPage","@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/","url":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/","name":"Build an Alcohol Detection Engine Lock System","isPartOf":{"@id":"https://www.engineersgarage.com/#website"},"primaryImageOfPage":{"@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#primaryimage"},"image":{"@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#primaryimage"},"thumbnailUrl":"https://www.engineersgarage.com/wp-content/uploads/2024/06/Demo2-rotator.png","datePublished":"2024-06-26T03:50:05+00:00","description":"The MQ3 alcohol gas sensor detects the alcohol and passes a signal to Arduino, which locks a vehicle's engine with the help of a relay.","breadcrumb":{"@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#primaryimage","url":"https://www.engineersgarage.com/wp-content/uploads/2024/06/Demo2-rotator.png","contentUrl":"https://www.engineersgarage.com/wp-content/uploads/2024/06/Demo2-rotator.png","width":800,"height":507},{"@type":"BreadcrumbList","@id":"https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://www.engineersgarage.com/"},{"@type":"ListItem","position":2,"name":"How to build an alcohol detector with the MQ3 gas sensor"}]},{"@type":"WebSite","@id":"https://www.engineersgarage.com/#website","url":"https://www.engineersgarage.com/","name":"Engineers Garage","description":"Electronic Projects, Electrical Engineering Resources, Makers Articles and Product News","publisher":{"@id":"https://www.engineersgarage.com/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://www.engineersgarage.com/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https://www.engineersgarage.com/#organization","name":"Engineer's Garage - WTWH Media","url":"https://www.engineersgarage.com/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https://www.engineersgarage.com/#/schema/logo/image/","url":"https://www.engineersgarage.com/wp-content/uploads/2019/08/EGlogo.png","contentUrl":"https://www.engineersgarage.com/wp-content/uploads/2019/08/EGlogo.png","width":372,"height":52,"caption":"Engineer's Garage - WTWH Media"},"image":{"@id":"https://www.engineersgarage.com/#/schema/logo/image/"},"sameAs":["https://www.facebook.com/engineersgarage","https://x.com/EngineersGarage","https://www.youtube.com/channel/UC0VITh11JSYk-UW7toLebUw"]},{"@type":"Person","@id":"https://www.engineersgarage.com/#/schema/person/f5e457ba68d983ca6ce696db9b2304b9","name":"Ayush Jain","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https://www.engineersgarage.com/#/schema/person/image/","url":"https://secure.gravatar.com/avatar/2b2bbad30a98592d01ea6cb9381fdb36?s=96&r=g","contentUrl":"https://secure.gravatar.com/avatar/2b2bbad30a98592d01ea6cb9381fdb36?s=96&r=g","caption":"Ayush Jain"},"url":"https://www.engineersgarage.com/author/ayush-jain/"}]}</script>  <link rel='dns-prefetch' href='//static.addtoany.com' /> <link rel='dns-prefetch' href='//kit.fontawesome.com' /> <link rel="alternate" type="application/rss+xml" title="Engineers Garage » Feed" href="https://www.engineersgarage.com/feed/" /> <link rel="alternate" type="application/rss+xml" title="Engineers Garage » Comments Feed" href="https://www.engineersgarage.com/comments/feed/" /> <link rel="alternate" type="application/rss+xml" title="Engineers Garage » How to build an alcohol detector with the MQ3 gas sensor Comments Feed" href="https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/feed/" /> <script type="text/javascript"> /* <![CDATA[ */ window._wpemojiSettings = {"baseUrl":"https:\/\/s.w.org\/images\/core\/emoji\/15.0.3\/72x72\/","ext":".png","svgUrl":"https:\/\/s.w.org\/images\/core\/emoji\/15.0.3\/svg\/","svgExt":".svg","source":{"concatemoji":"https:\/\/www.engineersgarage.com\/wp-includes\/js\/wp-emoji-release.min.js?ver=6.7.2"}}; /*! This file is auto-generated */ !function(i,n){var o,s,e;function c(e){try{var t={supportTests:e,timestamp:(new Date).valueOf()};sessionStorage.setItem(o,JSON.stringify(t))}catch(e){}}function p(e,t,n){e.clearRect(0,0,e.canvas.width,e.canvas.height),e.fillText(t,0,0);var t=new Uint32Array(e.getImageData(0,0,e.canvas.width,e.canvas.height).data),r=(e.clearRect(0,0,e.canvas.width,e.canvas.height),e.fillText(n,0,0),new Uint32Array(e.getImageData(0,0,e.canvas.width,e.canvas.height).data));return t.every(function(e,t){return e===r[t]})}function u(e,t,n){switch(t){case"flag":return n(e,"\ud83c\udff3\ufe0f\u200d\u26a7\ufe0f","\ud83c\udff3\ufe0f\u200b\u26a7\ufe0f")?!1:!n(e,"\ud83c\uddfa\ud83c\uddf3","\ud83c\uddfa\u200b\ud83c\uddf3")&&!n(e,"\ud83c\udff4\udb40\udc67\udb40\udc62\udb40\udc65\udb40\udc6e\udb40\udc67\udb40\udc7f","\ud83c\udff4\u200b\udb40\udc67\u200b\udb40\udc62\u200b\udb40\udc65\u200b\udb40\udc6e\u200b\udb40\udc67\u200b\udb40\udc7f");case"emoji":return!n(e,"\ud83d\udc26\u200d\u2b1b","\ud83d\udc26\u200b\u2b1b")}return!1}function f(e,t,n){var r="undefined"!=typeof WorkerGlobalScope&&self instanceof WorkerGlobalScope?new OffscreenCanvas(300,150):i.createElement("canvas"),a=r.getContext("2d",{willReadFrequently:!0}),o=(a.textBaseline="top",a.font="600 32px Arial",{});return e.forEach(function(e){o[e]=t(a,e,n)}),o}function t(e){var t=i.createElement("script");t.src=e,t.defer=!0,i.head.appendChild(t)}"undefined"!=typeof Promise&&(o="wpEmojiSettingsSupports",s=["flag","emoji"],n.supports={everything:!0,everythingExceptFlag:!0},e=new Promise(function(e){i.addEventListener("DOMContentLoaded",e,{once:!0})}),new Promise(function(t){var n=function(){try{var e=JSON.parse(sessionStorage.getItem(o));if("object"==typeof e&&"number"==typeof e.timestamp&&(new Date).valueOf()<e.timestamp+604800&&"object"==typeof e.supportTests)return e.supportTests}catch(e){}return null}();if(!n){if("undefined"!=typeof Worker&&"undefined"!=typeof OffscreenCanvas&&"undefined"!=typeof URL&&URL.createObjectURL&&"undefined"!=typeof Blob)try{var e="postMessage("+f.toString()+"("+[JSON.stringify(s),u.toString(),p.toString()].join(",")+"));",r=new Blob([e],{type:"text/javascript"}),a=new Worker(URL.createObjectURL(r),{name:"wpTestEmojiSupports"});return void(a.onmessage=function(e){c(n=e.data),a.terminate(),t(n)})}catch(e){}c(n=f(s,u,p))}t(n)}).then(function(e){for(var t in e)n.supports[t]=e[t],n.supports.everything=n.supports.everything&&n.supports[t],"flag"!==t&&(n.supports.everythingExceptFlag=n.supports.everythingExceptFlag&&n.supports[t]);n.supports.everythingExceptFlag=n.supports.everythingExceptFlag&&!n.supports.flag,n.DOMReady=!1,n.readyCallback=function(){n.DOMReady=!0}}).then(function(){return e}).then(function(){var e;n.supports.everything||(n.readyCallback(),(e=n.source||{}).concatemoji?t(e.concatemoji):e.wpemoji&&e.twemoji&&(t(e.twemoji),t(e.wpemoji)))}))}((window,document),window._wpemojiSettings); /* ]]> */ </script> <link rel='stylesheet' id='genesis-blocks-style-css-css' href='https://www.engineersgarage.com/wp-content/plugins/genesis-blocks/dist/style-blocks.build.css?ver=1732716289' type='text/css' media='all' /> <link rel='stylesheet' id='genesis-simple-share-plugin-css-css' href='https://www.engineersgarage.com/wp-content/plugins/genesis-simple-share/assets/css/share.min.css?ver=0.1.0' type='text/css' media='all' /> <link rel='stylesheet' id='genesis-simple-share-genericons-css-css' href='https://www.engineersgarage.com/wp-content/plugins/genesis-simple-share/assets/css/genericons.min.css?ver=0.1.0' type='text/css' media='all' /> <link rel='stylesheet' id='theme-wtwh-amplifying-css' href='https://www.engineersgarage.com/wp-content/themes/ThemeWTWHv2/style.css?ver=1705628983' type='text/css' media='all' /> <style id='wp-emoji-styles-inline-css' type='text/css'> img.wp-smiley, img.emoji { display: inline !important; border: none !important; box-shadow: none !important; height: 1em !important; width: 1em !important; margin: 0 0.07em !important; vertical-align: -0.1em !important; background: none !important; padding: 0 !important; } </style> <link rel='stylesheet' id='wp-block-library-css' href='https://www.engineersgarage.com/wp-includes/css/dist/block-library/style.min.css?ver=6.7.2' type='text/css' media='all' /> <style id='classic-theme-styles-inline-css' type='text/css'> /*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} </style> <style id='global-styles-inline-css' type='text/css'> :root{--wp--preset--aspect-ratio--square: 1;--wp--preset--aspect-ratio--4-3: 4/3;--wp--preset--aspect-ratio--3-4: 3/4;--wp--preset--aspect-ratio--3-2: 3/2;--wp--preset--aspect-ratio--2-3: 2/3;--wp--preset--aspect-ratio--16-9: 16/9;--wp--preset--aspect-ratio--9-16: 9/16;--wp--preset--color--black: #000000;--wp--preset--color--cyan-bluish-gray: #abb8c3;--wp--preset--color--white: #ffffff;--wp--preset--color--pale-pink: #f78da7;--wp--preset--color--vivid-red: #cf2e2e;--wp--preset--color--luminous-vivid-orange: #ff6900;--wp--preset--color--luminous-vivid-amber: #fcb900;--wp--preset--color--light-green-cyan: #7bdcb5;--wp--preset--color--vivid-green-cyan: #00d084;--wp--preset--color--pale-cyan-blue: #8ed1fc;--wp--preset--color--vivid-cyan-blue: #0693e3;--wp--preset--color--vivid-purple: #9b51e0;--wp--preset--gradient--vivid-cyan-blue-to-vivid-purple: linear-gradient(135deg,rgba(6,147,227,1) 0%,rgb(155,81,224) 100%);--wp--preset--gradient--light-green-cyan-to-vivid-green-cyan: linear-gradient(135deg,rgb(122,220,180) 0%,rgb(0,208,130) 100%);--wp--preset--gradient--luminous-vivid-amber-to-luminous-vivid-orange: linear-gradient(135deg,rgba(252,185,0,1) 0%,rgba(255,105,0,1) 100%);--wp--preset--gradient--luminous-vivid-orange-to-vivid-red: linear-gradient(135deg,rgba(255,105,0,1) 0%,rgb(207,46,46) 100%);--wp--preset--gradient--very-light-gray-to-cyan-bluish-gray: linear-gradient(135deg,rgb(238,238,238) 0%,rgb(169,184,195) 100%);--wp--preset--gradient--cool-to-warm-spectrum: linear-gradient(135deg,rgb(74,234,220) 0%,rgb(151,120,209) 20%,rgb(207,42,186) 40%,rgb(238,44,130) 60%,rgb(251,105,98) 80%,rgb(254,248,76) 100%);--wp--preset--gradient--blush-light-purple: linear-gradient(135deg,rgb(255,206,236) 0%,rgb(152,150,240) 100%);--wp--preset--gradient--blush-bordeaux: linear-gradient(135deg,rgb(254,205,165) 0%,rgb(254,45,45) 50%,rgb(107,0,62) 100%);--wp--preset--gradient--luminous-dusk: linear-gradient(135deg,rgb(255,203,112) 0%,rgb(199,81,192) 50%,rgb(65,88,208) 100%);--wp--preset--gradient--pale-ocean: linear-gradient(135deg,rgb(255,245,203) 0%,rgb(182,227,212) 50%,rgb(51,167,181) 100%);--wp--preset--gradient--electric-grass: linear-gradient(135deg,rgb(202,248,128) 0%,rgb(113,206,126) 100%);--wp--preset--gradient--midnight: linear-gradient(135deg,rgb(2,3,129) 0%,rgb(40,116,252) 100%);--wp--preset--font-size--small: 13px;--wp--preset--font-size--medium: 20px;--wp--preset--font-size--large: 36px;--wp--preset--font-size--x-large: 42px;--wp--preset--spacing--20: 0.44rem;--wp--preset--spacing--30: 0.67rem;--wp--preset--spacing--40: 1rem;--wp--preset--spacing--50: 1.5rem;--wp--preset--spacing--60: 2.25rem;--wp--preset--spacing--70: 3.38rem;--wp--preset--spacing--80: 5.06rem;--wp--preset--shadow--natural: 6px 6px 9px rgba(0, 0, 0, 0.2);--wp--preset--shadow--deep: 12px 12px 50px rgba(0, 0, 0, 0.4);--wp--preset--shadow--sharp: 6px 6px 0px rgba(0, 0, 0, 0.2);--wp--preset--shadow--outlined: 6px 6px 0px -3px rgba(255, 255, 255, 1), 6px 6px rgba(0, 0, 0, 1);--wp--preset--shadow--crisp: 6px 6px 0px rgba(0, 0, 0, 1);}:where(.is-layout-flex){gap: 0.5em;}:where(.is-layout-grid){gap: 0.5em;}body .is-layout-flex{display: flex;}.is-layout-flex{flex-wrap: wrap;align-items: center;}.is-layout-flex > :is(*, div){margin: 0;}body .is-layout-grid{display: grid;}.is-layout-grid > :is(*, div){margin: 0;}:where(.wp-block-columns.is-layout-flex){gap: 2em;}:where(.wp-block-columns.is-layout-grid){gap: 2em;}:where(.wp-block-post-template.is-layout-flex){gap: 1.25em;}:where(.wp-block-post-template.is-layout-grid){gap: 1.25em;}.has-black-color{color: var(--wp--preset--color--black) !important;}.has-cyan-bluish-gray-color{color: var(--wp--preset--color--cyan-bluish-gray) !important;}.has-white-color{color: var(--wp--preset--color--white) !important;}.has-pale-pink-color{color: var(--wp--preset--color--pale-pink) !important;}.has-vivid-red-color{color: var(--wp--preset--color--vivid-red) !important;}.has-luminous-vivid-orange-color{color: var(--wp--preset--color--luminous-vivid-orange) !important;}.has-luminous-vivid-amber-color{color: var(--wp--preset--color--luminous-vivid-amber) !important;}.has-light-green-cyan-color{color: var(--wp--preset--color--light-green-cyan) !important;}.has-vivid-green-cyan-color{color: var(--wp--preset--color--vivid-green-cyan) !important;}.has-pale-cyan-blue-color{color: var(--wp--preset--color--pale-cyan-blue) !important;}.has-vivid-cyan-blue-color{color: var(--wp--preset--color--vivid-cyan-blue) !important;}.has-vivid-purple-color{color: var(--wp--preset--color--vivid-purple) !important;}.has-black-background-color{background-color: var(--wp--preset--color--black) !important;}.has-cyan-bluish-gray-background-color{background-color: var(--wp--preset--color--cyan-bluish-gray) !important;}.has-white-background-color{background-color: var(--wp--preset--color--white) !important;}.has-pale-pink-background-color{background-color: var(--wp--preset--color--pale-pink) !important;}.has-vivid-red-background-color{background-color: var(--wp--preset--color--vivid-red) !important;}.has-luminous-vivid-orange-background-color{background-color: var(--wp--preset--color--luminous-vivid-orange) !important;}.has-luminous-vivid-amber-background-color{background-color: var(--wp--preset--color--luminous-vivid-amber) !important;}.has-light-green-cyan-background-color{background-color: var(--wp--preset--color--light-green-cyan) !important;}.has-vivid-green-cyan-background-color{background-color: var(--wp--preset--color--vivid-green-cyan) !important;}.has-pale-cyan-blue-background-color{background-color: var(--wp--preset--color--pale-cyan-blue) !important;}.has-vivid-cyan-blue-background-color{background-color: var(--wp--preset--color--vivid-cyan-blue) !important;}.has-vivid-purple-background-color{background-color: var(--wp--preset--color--vivid-purple) !important;}.has-black-border-color{border-color: var(--wp--preset--color--black) !important;}.has-cyan-bluish-gray-border-color{border-color: var(--wp--preset--color--cyan-bluish-gray) !important;}.has-white-border-color{border-color: var(--wp--preset--color--white) !important;}.has-pale-pink-border-color{border-color: var(--wp--preset--color--pale-pink) !important;}.has-vivid-red-border-color{border-color: var(--wp--preset--color--vivid-red) !important;}.has-luminous-vivid-orange-border-color{border-color: var(--wp--preset--color--luminous-vivid-orange) !important;}.has-luminous-vivid-amber-border-color{border-color: var(--wp--preset--color--luminous-vivid-amber) !important;}.has-light-green-cyan-border-color{border-color: var(--wp--preset--color--light-green-cyan) !important;}.has-vivid-green-cyan-border-color{border-color: var(--wp--preset--color--vivid-green-cyan) !important;}.has-pale-cyan-blue-border-color{border-color: var(--wp--preset--color--pale-cyan-blue) !important;}.has-vivid-cyan-blue-border-color{border-color: var(--wp--preset--color--vivid-cyan-blue) !important;}.has-vivid-purple-border-color{border-color: var(--wp--preset--color--vivid-purple) !important;}.has-vivid-cyan-blue-to-vivid-purple-gradient-background{background: var(--wp--preset--gradient--vivid-cyan-blue-to-vivid-purple) !important;}.has-light-green-cyan-to-vivid-green-cyan-gradient-background{background: var(--wp--preset--gradient--light-green-cyan-to-vivid-green-cyan) !important;}.has-luminous-vivid-amber-to-luminous-vivid-orange-gradient-background{background: var(--wp--preset--gradient--luminous-vivid-amber-to-luminous-vivid-orange) !important;}.has-luminous-vivid-orange-to-vivid-red-gradient-background{background: var(--wp--preset--gradient--luminous-vivid-orange-to-vivid-red) !important;}.has-very-light-gray-to-cyan-bluish-gray-gradient-background{background: var(--wp--preset--gradient--very-light-gray-to-cyan-bluish-gray) !important;}.has-cool-to-warm-spectrum-gradient-background{background: var(--wp--preset--gradient--cool-to-warm-spectrum) !important;}.has-blush-light-purple-gradient-background{background: var(--wp--preset--gradient--blush-light-purple) !important;}.has-blush-bordeaux-gradient-background{background: var(--wp--preset--gradient--blush-bordeaux) !important;}.has-luminous-dusk-gradient-background{background: var(--wp--preset--gradient--luminous-dusk) !important;}.has-pale-ocean-gradient-background{background: var(--wp--preset--gradient--pale-ocean) !important;}.has-electric-grass-gradient-background{background: var(--wp--preset--gradient--electric-grass) !important;}.has-midnight-gradient-background{background: var(--wp--preset--gradient--midnight) !important;}.has-small-font-size{font-size: var(--wp--preset--font-size--small) !important;}.has-medium-font-size{font-size: var(--wp--preset--font-size--medium) !important;}.has-large-font-size{font-size: var(--wp--preset--font-size--large) !important;}.has-x-large-font-size{font-size: var(--wp--preset--font-size--x-large) !important;} :where(.wp-block-post-template.is-layout-flex){gap: 1.25em;}:where(.wp-block-post-template.is-layout-grid){gap: 1.25em;} :where(.wp-block-columns.is-layout-flex){gap: 2em;}:where(.wp-block-columns.is-layout-grid){gap: 2em;} :root :where(.wp-block-pullquote){font-size: 1.5em;line-height: 1.6;} </style> <link rel='stylesheet' id='megamenu-css' href='https://www.engineersgarage.com/wp-content/uploads/maxmegamenu/style.css?ver=404bb3' type='text/css' media='all' /> <link rel='stylesheet' id='dashicons-css' href='https://www.engineersgarage.com/wp-includes/css/dashicons.min.css?ver=6.7.2' type='text/css' media='all' /> <link rel='stylesheet' id='ea-style-css' href='https://www.engineersgarage.com/wp-content/themes/ThemeWTWHv2/assets/css/main.css?ver=1705628983' type='text/css' media='all' /> <style id='akismet-widget-style-inline-css' type='text/css'> .a-stats { --akismet-color-mid-green: #357b49; --akismet-color-white: #fff; --akismet-color-light-grey: #f6f7f7; max-width: 350px; width: auto; } .a-stats * { all: unset; box-sizing: border-box; } .a-stats strong { font-weight: 600; } .a-stats a.a-stats__link, .a-stats a.a-stats__link:visited, .a-stats a.a-stats__link:active { background: var(--akismet-color-mid-green); border: none; box-shadow: none; border-radius: 8px; color: var(--akismet-color-white); cursor: pointer; display: block; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen-Sans', 'Ubuntu', 'Cantarell', 'Helvetica Neue', sans-serif; font-weight: 500; padding: 12px; text-align: center; text-decoration: none; transition: all 0.2s ease; } /* Extra specificity to deal with TwentyTwentyOne focus style */ .widget .a-stats a.a-stats__link:focus { background: var(--akismet-color-mid-green); color: var(--akismet-color-white); text-decoration: none; } .a-stats a.a-stats__link:hover { filter: brightness(110%); box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06), 0 0 2px rgba(0, 0, 0, 0.16); } .a-stats .count { color: var(--akismet-color-white); display: block; font-size: 1.5em; line-height: 1.4; padding: 0 13px; white-space: nowrap; } </style> <link rel='stylesheet' id='simple-social-icons-font-css' href='https://www.engineersgarage.com/wp-content/plugins/simple-social-icons/css/style.css?ver=3.0.2' type='text/css' media='all' /> <link rel='stylesheet' id='tablepress-default-css' href='https://www.engineersgarage.com/wp-content/plugins/tablepress/css/build/default.css?ver=3.0.3' type='text/css' media='all' /> <link rel='stylesheet' id='addtoany-css' href='https://www.engineersgarage.com/wp-content/plugins/add-to-any/addtoany.min.css?ver=1.16' type='text/css' media='all' /> <link rel='stylesheet' id='wtwh-uni-gam-prestitial-style-css' href='https://www.engineersgarage.com/wp-content/plugins/wtwh-universal-gam/assets/css/frontend/prestitial/prestitial.css?ver=1.1.1' type='text/css' media='all' /> <link rel='stylesheet' id='genesis-tabs-stylesheet-css' href='https://www.engineersgarage.com/wp-content/plugins/genesis-tabs/assets/css/style.css?ver=0.9.5' type='text/css' media='all' /> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/jquery/jquery.min.js?ver=3.7.1" id="jquery-core-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-content/plugins/genesis-simple-share/assets/js/sharrre/jquery.sharrre.min.js?ver=0.1.0" id="genesis-simple-share-plugin-js-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-content/plugins/genesis-simple-share/assets/js/waypoints.min.js?ver=0.1.0" id="genesis-simple-share-waypoint-js-js"></script> <script type="text/javascript" id="addtoany-core-js-before"> /* <![CDATA[ */ window.a2a_config=window.a2a_config||{};a2a_config.callbacks=[];a2a_config.overlays=[];a2a_config.templates={}; a2a_config.track_links = 'bitly'; a2a_config.track_links_key = 'addtoany|R_cc6a4017b0274d1d86f2397771b70136'; // username|API key delimited by | a2a_config.templates = { twitter: "${title} ${link} via @EngineersGarage" }; /* ]]> */ </script> <script type="text/javascript" defer src="https://static.addtoany.com/menu/page.js" id="addtoany-core-js"></script> <script type="text/javascript" defer src="https://www.engineersgarage.com/wp-content/plugins/add-to-any/addtoany.min.js?ver=1.1" id="addtoany-jquery-js"></script> <script type="text/javascript" src="https://kit.fontawesome.com/371676a4da.js?ver=1.1.1" id="wtwh-uni-gam-prestitial-font-awesome-js"></script> <link rel="https://api.w.org/" href="https://www.engineersgarage.com/wp-json/" /><link rel="alternate" title="JSON" type="application/json" href="https://www.engineersgarage.com/wp-json/wp/v2/posts/81297" /><link rel='shortlink' href='https://www.engineersgarage.com/?p=81297' /> <link rel="alternate" title="oEmbed (JSON)" type="application/json+oembed" href="https://www.engineersgarage.com/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.engineersgarage.com%2Fhow-to-build-an-alcohol-detector-with-the-mq3-gas-sensor%2F" /> <link rel="alternate" title="oEmbed (XML)" type="text/xml+oembed" href="https://www.engineersgarage.com/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.engineersgarage.com%2Fhow-to-build-an-alcohol-detector-with-the-mq3-gas-sensor%2F&format=xml" /> <style> #category-posts-2-internal ul {padding: 0;} #category-posts-2-internal .cat-post-item img {max-width: initial; max-height: initial; margin: initial;} #category-posts-2-internal .cat-post-author {margin-bottom: 0;} #category-posts-2-internal .cat-post-thumbnail {margin: 5px 10px 5px 0;} #category-posts-2-internal .cat-post-item:before {content: ""; clear: both;} #category-posts-2-internal .cat-post-excerpt-more {display: inline-block;} #category-posts-2-internal .cat-post-item {list-style: none; margin: 3px 0 10px; padding: 3px 0;} #category-posts-2-internal .cat-post-current .cat-post-title {font-weight: bold; text-transform: uppercase;} #category-posts-2-internal [class*=cat-post-tax] {font-size: 0.85em;} #category-posts-2-internal [class*=cat-post-tax] * {display:inline-block;} #category-posts-2-internal .cat-post-item:after {content: ""; display: table; clear: both;} #category-posts-2-internal .cat-post-item .cat-post-title {overflow: hidden;text-overflow: ellipsis;white-space: initial;display: -webkit-box;-webkit-line-clamp: 4;-webkit-box-orient: vertical;padding-bottom: 0 !important;} #category-posts-2-internal .cat-post-item:after {content: ""; display: table; clear: both;} #category-posts-2-internal .cat-post-thumbnail {display:block; float:left; margin:5px 10px 5px 0;} #category-posts-2-internal .cat-post-crop {overflow:hidden;display:block;} #category-posts-2-internal p {margin:5px 0 0 0} #category-posts-2-internal li > div {margin:5px 0 0 0; clear:both;} #category-posts-2-internal .dashicons {vertical-align:middle;} #category-posts-2-internal .cat-post-thumbnail .cat-post-crop img {height: 95px;} #category-posts-2-internal .cat-post-thumbnail .cat-post-crop img {width: 150px;} #category-posts-2-internal .cat-post-thumbnail .cat-post-crop img {object-fit: cover; max-width: 100%; display: block;} #category-posts-2-internal .cat-post-thumbnail .cat-post-crop-not-supported img {width: 100%;} #category-posts-2-internal .cat-post-thumbnail {max-width:100%;} #category-posts-2-internal .cat-post-item img {margin: initial;} #category-posts-2-internal .cat-post-dark img {padding-bottom: 0 !important; -webkit-transition: all 0.3s ease; -moz-transition: all 0.3s ease; -ms-transition: all 0.3s ease; -o-transition: all 0.3s ease; transition: all 0.3s ease;} #category-posts-2-internal .cat-post-dark:hover img {-webkit-filter: brightness(75%); -moz-filter: brightness(75%); -ms-filter: brightness(75%); -o-filter: brightness(75%); filter: brightness(75%);} </style>  <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= 'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-MMC9PJ9');</script>   <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= 'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-NJMRR6Z');</script>  <link rel="icon" href="https://www.engineersgarage.com/wp-content/uploads/2019/08/cropped-eg-favicon-32x32.png" sizes="32x32" /> <link rel="icon" href="https://www.engineersgarage.com/wp-content/uploads/2019/08/cropped-eg-favicon-192x192.png" sizes="192x192" /> <link rel="apple-touch-icon" href="https://www.engineersgarage.com/wp-content/uploads/2019/08/cropped-eg-favicon-180x180.png" /> <meta name="msapplication-TileImage" content="https://www.engineersgarage.com/wp-content/uploads/2019/08/cropped-eg-favicon-270x270.png" /> <style type="text/css" id="wp-custom-css"> /*body > div.site-container > div.site-inner > div > div > main > article > div > p > a { color: #D2232A; }*/ .entry-content a { font-weight: bold; } .site-header .title-area { width: 350px; } @media only screen and (max-width: 1152px) { .site-header .title-area { width: 230px; } } .wtwhSpecial { display: none !important; } article > div > p > a { font-weight: bold; color:#337ab7; text-decoration: underline; } /*RSS FEED FIX*/ #rss-3 > div > h4 > a { font-size: 20px; font-weight: bold; float: none !important; } #rss-3 > div > h4 > a > img { display: none; } #rss-3 > div > ul { width: 100%; padding-left: 30px; } #rss-2 > div > h4 > a { font-size: 20px; font-weight: bold; float: none !important; } #rss-2 > div > h4 > a > img { display: none; } #rss-2 > div > ul { width: 100%; padding-left: 30px; } #recent-posts-2 > .widget-wrap > ul { padding-left: 30px; } .video-carousel .video-popup:before { background: none !important; } .video-carousel .video-popup:after { color: red !important; } .entry-categories a { font-weight: normal;} .entry-tags a{font-weight: normal;} .entry-categories { font-weight: bold;} .entry-tags {font-weight: bold;} .bawmrp a { font-weight: 400; } #digital > span { font-size: 16px !important; font-weight: 400 !important; } xmp { white-space:normal; } .slick-slider .col-sm-4 .header-slide, .slick-slider .col-sm-4 .header-slide img { max-height:240px; object-fit:cover; } .slick-slider .col-sm-8 .header-slide, .slick-slider .col-sm-8 .header-slide img { object-fit:cover; max-height:500px; } /*EE Classrooms*/ .motion-design-guides { font-size: 18px; font-weight: bold; width: 270px; height: 60px; text-align: center; text-align-last: center; -moz-text-align-last: center; border-radius: 0px; background-color: #313131; color: white; border-bottom: 4px solid #1f427e; text-transform: uppercase; white-space: wrap; } .motion-design-guide-option { text-align: center; text-align-last: center; -moz-text-align-last: center; text-transform: uppercase; width: 270px; white-space: wrap; } /*Fix for Categories/home page article display*/ @media only screen and (max-width: 500px) { .content .entry .entry-header, .archive-entry .entry-header { /* width: 100% !important;*/ /*padding-left: 0px !important; float: none !important;*/ } /* .content .entry .entry-content { width: 100% !important; }*/ /* .entry-content p { float: none !important; }*/ .entry-content img { text-align: center !important; width: 100% !important; } .archive-entry { display: flex; flex-direction: column-reverse; width: 100% !important; } .archive-entry > .entry-header, .archive-entry .entry-content { width: 100% !important; } /*.archive-entry .entry-image-link img { width: 100% !important; }*/ } @media only screen and (max-width: 767px) { .archive.category .entry-content p { display: none !important } .blog .entry-content p { display: none !important; } } .slick-slider.header-slides .header-slide .overlay h4, .slick-slider.header-slides .header-slide .overlay h2 { text-shadow: 2px 2px 5px black; background: none !important; -webkit-text-stroke-width: 0px !important; -webkit-text-stroke-color: transparent !important; } .nav-previous{ float:left; margin-bottom:50px } .nav-next{ float:right; margin-bottom:50px } .dropbtn { background-color: #04AA6D; color: white; padding: 16px; font-size: 16px; border: none; } .dropdown { display: inline-block; } .dropdown-content { display: none; position: absolute; background-color: #f1f1f1; min-width: 160px; box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2); z-index: 1; } .dropdown-content a { color: black; padding: 12px 16px; text-decoration: none; display: block; } .dropdown-content a:hover {background-color: #ddd;} .dropdown:hover .dropdown-content {display: block;} .dropdown:hover .dropbtn {background-color: #3e8e41;} /*Design Guide Drop Down Menu*/ .motion-design-guides { font-size: 14px; font-family: Raleway, sans-serif; width: 270px; height: 50px; text-align: center; text-align-last: center; -moz-text-align-last: center; border-radius: 0px; background-color: white; color: #000; border-top: 3px solid #000; border-left: none; border-right: none; border-bottom: 1px solid #e3e3e3; text-transform: uppercase; white-space: wrap; } .motion-design-guide-option { text-align: center; text-align-last: center; -moz-text-align-last: center; text-transform: uppercase; width: 270px; white-space: wrap; } .motion-design-guides:after { content: ""; border: solid #000; border-width: 0 2px 2px 0; margin-left: 20px; margin-bottom: 3px; display: inline-block; padding: 2.5px; transform: rotate(45deg); -webkit-transform: rotate(45deg); } /*Overlapping Header article Title fix*/ @media only screen and (max-width: 780px) { .site-container { margin-top: 40px !important; } } p.must-log-in a, p.logged-in-as a { color: #23527c !important; font-weight: bold; } article li a { color: #337ab7; text-decoration: underline; } /* Search Page */ body.search .site-inner { padding-left: unset; padding-right: unset; } @media only screen and (min-width: 988px) { .search .content { width: 66% !important; float: left; } .search .sidebar { width: 30%; float: right; } } </style> <script async id="wtwh-uni-gam-ad-manager-lib" src="https://securepubads.g.doubleclick.net/tag/js/gpt.js"></script> <script id="wtwh-uni-gam-keyword-ads-variables">var KEYWORDADS = {"hasKeywordAds":0};</script> <script id="wtwh-uni-gam-ott-variables">var OTTINFO = { "hasOTT":0, "name":"", "prestital_behavior":"", "jumbo_banner_behavior":"" };</script> <script id="wtwh-uni-gam-ad-units"> window.googletag = window.googletag || {cmd: []}; googletag.cmd.push(function() { googletag .defineSlot( '/5272491/ee_network/eg_header', [[728, 90],[300, 250]], 'div-gpt-eg-header' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [728, 90]) .addSize([768, 0], [728, 90]) .addSize([320, 0], [300, 250]) .addSize([0, 0], [300, 250]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_wallpaper', [1, 1], 'div-gpt-eg_wallpaper' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [1, 1]) .addSize([768, 0], [1, 1]) .addSize([320, 0], [1, 1]) .addSize([0, 0], [1, 1]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_allstreamflex', [1, 1], 'div-gpt-eg_allstreamflex' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [1, 1]) .addSize([768, 0], [1, 1]) .addSize([320, 0], [1, 1]) .addSize([0, 0], [1, 1]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_allstreamprelude', [1, 1], 'div-gpt-eg_allstreamprelude' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [1, 1]) .addSize([768, 0], [1, 1]) .addSize([320, 0], [1, 1]) .addSize([0, 0], [1, 1]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_sidebar1', [[300, 250],[300, 600]], 'div-gpt-eg_sidebar1' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [[300, 250],[300, 600]]) .addSize([768, 0], [[300, 250],[300, 600]]) .addSize([320, 0], [300, 250]) .addSize([0, 0], [300, 250]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_sidebarbottom', [[300, 250],[300, 600]], 'div-gpt-eg_sidebarbottom' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [[300, 250],[300, 600]]) .addSize([768, 0], [[300, 250],[300, 600]]) .addSize([320, 0], [300, 250]) .addSize([0, 0], [300, 250]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_storeribbon', [[728, 90],[970, 250]], 'div-gpt-eg_storeribbon' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [[728, 90],[970, 250]]) .addSize([768, 0], [[728, 90],[970, 250]]) .addSize([320, 0], [0, 0]) .addSize([0, 0], [0, 0]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_prestitial', [[640, 480],[300, 225]], 'gam-holder-prestitial-banner' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [640, 480]) .addSize([768, 0], [640, 480]) .addSize([320, 0], [300, 225]) .addSize([0, 0], [300, 225]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); googletag .defineSlot( '/5272491/ee_network/eg_largeleader', [[970, 90],[970, 250]], 'div-gpt-eg_largeleader' ) .defineSizeMapping( googletag .sizeMapping() .addSize([991, 0], [[970, 90],[970, 250]]) .addSize([768, 0], [[970, 90],[970, 250]]) .addSize([320, 0], [0, 0]) .addSize([0, 0], [0, 0]) .build() ) .setTargeting( 'articletitle', ['how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor'] ) .setTargeting( 'cat_target', ['5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros'] ) .setTargeting( 'contentHash', ['5716e3defaae93c1b9156263b6f0fdeb'] ) .addService( googletag.pubads() ); // googletag.pubads().enableSingleRequest(); googletag.pubads().collapseEmptyDivs(); googletag.enableServices(); }); </script> <script id="wtwh-uni-gam-content-hash-variables"> var contentHash = "5716e3defaae93c1b9156263b6f0fdeb"; var cat_target = "5716e3defaae93c1b9156263b6f0fdeb,circuit_design,video,ros"; </script> <style type="text/css">/** Mega Menu CSS: fs **/</style> </head> <body class="post-template-default single single-post postid-81297 single-format-standard mega-menu-primary header-image content-sidebar genesis-breadcrumbs-hidden">  <div id="prestitial" class="prestitial-no-show" style="opacity: 0;"> <div id="prestitial-overlay"></div> <div id="prestitial-grid"></div> </div> <div class="site-container"><header class="site-header"><div class="wrap"><div class="title-area"><p class="site-title"><a href="https://www.engineersgarage.com/">Engineers Garage</a></p></div><div class="widget-area header-widget-area"><section id="custom_html-2" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><div class="textwidget custom-html-widget"><div id='div-gpt-eg-header'> <script> googletag.cmd.push(function() { googletag.display('div-gpt-eg-header'); }); </script> </div> </div></div></section> </div><div class="mobile-toggles"><a href="#" class="search-toggle"><i class="icon-search"></i></a><a href="#" class="mobile-menu-toggle"><i class="icon-menu"></i></a></div></div></header><nav class="nav-primary" aria-label="Main"><div class="wrap"><div id="mega-menu-wrap-primary" class="mega-menu-wrap"><div class="mega-menu-toggle"><div class="mega-toggle-blocks-left"></div><div class="mega-toggle-blocks-center"></div><div class="mega-toggle-blocks-right"><div class='mega-toggle-block mega-menu-toggle-animated-block mega-toggle-block-0' id='mega-toggle-block-0'><button aria-label="Toggle Menu" class="mega-toggle-animated mega-toggle-animated-slider" type="button" aria-expanded="false"> <span class="mega-toggle-animated-box"> <span class="mega-toggle-animated-inner"></span> </span> </button></div></div></div><ul id="mega-menu-primary" class="mega-menu max-mega-menu mega-menu-horizontal mega-no-js" data-event="hover_intent" data-effect="fade_up" data-effect-speed="200" data-effect-mobile="disabled" data-effect-speed-mobile="0" data-mobile-force-width="false" data-second-click="go" data-document-click="collapse" data-vertical-behaviour="standard" data-breakpoint="768" data-unbind="true" data-mobile-state="collapse_all" data-mobile-direction="vertical" data-hover-intent-timeout="300" data-hover-intent-interval="100"><li class='mega-menu-item mega-menu-item-type-post_type mega-menu-item-object-page mega-menu-item-has-children mega-align-bottom-left mega-menu-flyout mega-menu-item-61908' id='mega-menu-item-61908'><a class="mega-menu-link" href="https://www.engineersgarage.com/projects-and-tutorials/" aria-expanded="false" tabindex="0">Electronics Projects and Tutorials<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-has-children mega-menu-item-39808' id='mega-menu-item-39808'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/" aria-expanded="false">Electronic Projects<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-81272' id='mega-menu-item-81272'><a class="mega-menu-link" href="https://www.engineersgarage.com/arduino/">Arduino Projects</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-81273' id='mega-menu-item-81273'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/avr/">AVR</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-80793' id='mega-menu-item-80793'><a class="mega-menu-link" href="https://www.engineersgarage.com/raspberry-pi-electronic-projects/">Raspberry pi</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78430' id='mega-menu-item-78430'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/esp8266-electronic-projects/">ESP8266</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78434' id='mega-menu-item-78434'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/beaglebone-electronic-projects/">BeagleBone</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-80794' id='mega-menu-item-80794'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/8051-microcontroller/">8051 Microcontroller</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-55864' id='mega-menu-item-55864'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/arm-electronic-projects-electronic-projects/">ARM</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-80795' id='mega-menu-item-80795'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/pic-microcontroller-electronic-projects/">PIC Microcontroller</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-60239' id='mega-menu-item-60239'><a class="mega-menu-link" href="https://www.engineersgarage.com/electronic-projects/stm32-electronic-projects-electronic-projects/">STM32</a></li> </ul> </li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-has-children mega-menu-item-7268' id='mega-menu-item-7268'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/" aria-expanded="false">Tutorials<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78818' id='mega-menu-item-78818'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/audio-tutorials/">Audio Electronics</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78819' id='mega-menu-item-78819'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/battery-management-systems/">Battery Management</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78820' id='mega-menu-item-78820'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/brainwave/">Brainwave</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78833' id='mega-menu-item-78833'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/evs/">Electric Vehicles</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78822' id='mega-menu-item-78822'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/emc-emi/">EMI/EMC/RFI</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78823' id='mega-menu-item-78823'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/filters/">Hardware Filters</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78826' id='mega-menu-item-78826'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/iot-tutorials/">IoT tutorials</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-80151' id='mega-menu-item-80151'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/power/">Power Tutorials</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78835' id='mega-menu-item-78835'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/python/">Python</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78829' id='mega-menu-item-78829'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/sensors-tutorials/">Sensors</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78830' id='mega-menu-item-78830'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/usb/">USB</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-78832' id='mega-menu-item-78832'><a class="mega-menu-link" href="https://www.engineersgarage.com/tutorials/vhdl-tutorials/">VHDL</a></li> </ul> </li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-current-post-ancestor mega-current-menu-parent mega-current-post-parent mega-menu-item-56096' id='mega-menu-item-56096'><a class="mega-menu-link" href="https://www.engineersgarage.com/circuit_design/">Circuit Design</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-62725' id='mega-menu-item-62725'><a target="_blank" class="mega-menu-link" href="https://www.youtube.com/user/engineersgarage">Project Videos</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-7269' id='mega-menu-item-7269'><a class="mega-menu-link" href="https://www.engineersgarage.com/components/">Components</a></li></ul> </li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-has-children mega-align-bottom-left mega-menu-flyout mega-menu-item-39810' id='mega-menu-item-39810'><a class="mega-menu-link" href="https://www.engineersgarage.com/article_page/" aria-expanded="false" tabindex="0">Articles<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-63122' id='mega-menu-item-63122'><a class="mega-menu-link" href="https://www.engineersgarage.com/tech-articles/">Tech Articles</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-13371' id='mega-menu-item-13371'><a class="mega-menu-link" href="https://www.engineersgarage.com/insight/">Insight</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-13399' id='mega-menu-item-13399'><a class="mega-menu-link" href="https://www.engineersgarage.com/invention-stories/">Invention Stories</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-13326' id='mega-menu-item-13326'><a class="mega-menu-link" href="https://www.engineersgarage.com/how_to/">How to</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-59366' id='mega-menu-item-59366'><a class="mega-menu-link" href="https://www.engineersgarage.com/what_is/">What Is</a></li></ul> </li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-has-children mega-align-bottom-left mega-menu-flyout mega-menu-item-1863' id='mega-menu-item-1863'><a class="mega-menu-link" href="#" aria-expanded="false" tabindex="0">News<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-39809' id='mega-menu-item-39809'><a class="mega-menu-link" href="https://www.engineersgarage.com/news/">Electronic Product News</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-77696' id='mega-menu-item-77696'><a class="mega-menu-link" href="https://www.engineersgarage.com/news/business-news/">Business News</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-77697' id='mega-menu-item-77697'><a class="mega-menu-link" href="https://www.engineersgarage.com/news/company-start-up-news/">Company/Start-up News</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-14489' id='mega-menu-item-14489'><a class="mega-menu-link" href="https://www.engineersgarage.com/reviews/">DIY Reviews</a></li><li class='mega-menu-item mega-menu-item-type-taxonomy mega-menu-item-object-category mega-menu-item-14287' id='mega-menu-item-14287'><a class="mega-menu-link" href="https://www.engineersgarage.com/guest_post/">Guest Post</a></li></ul> </li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-has-children mega-align-bottom-left mega-menu-flyout mega-menu-item-55871' id='mega-menu-item-55871'><a class="mega-menu-link" aria-expanded="false" tabindex="0">Forums<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-55870' id='mega-menu-item-55870'><a class="mega-menu-link" href="https://www.edaboard.com/">EDABoard.com</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-55869' id='mega-menu-item-55869'><a class="mega-menu-link" href="https://www.electro-tech-online.com/">Electro-Tech-Online</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-1851' id='mega-menu-item-1851'><a class="mega-menu-link" href="https://forums.engineersgarage.com/">EG Forum Archive</a></li></ul> </li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-has-children mega-menu-megamenu mega-align-bottom-left mega-menu-megamenu mega-menu-item-1868' id='mega-menu-item-1868'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mk" aria-expanded="false" tabindex="0">DigiKey Store<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1869' id='mega-menu-item-1869'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9ml">Cables, Wires</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1870' id='mega-menu-item-1870'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mm">Connectors, Interconnect</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1871' id='mega-menu-item-1871'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mn">Discrete</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-clear mega-menu-item-1872' id='mega-menu-item-1872'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mo">Electromechanical</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1873' id='mega-menu-item-1873'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mp">Embedded Computers</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1874' id='mega-menu-item-1874'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mq">Enclosures, Hardware, Office</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-clear mega-menu-item-1875' id='mega-menu-item-1875'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mr">Integrated Circuits (ICs)</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1876' id='mega-menu-item-1876'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9ms">Isolators</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1877' id='mega-menu-item-1877'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mt">LED/Optoelectronics</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-clear mega-menu-item-1878' id='mega-menu-item-1878'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mu">Passive</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1879' id='mega-menu-item-1879'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mv">Power, Circuit Protection</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1880' id='mega-menu-item-1880'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mw">Programmers</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-clear mega-menu-item-1881' id='mega-menu-item-1881'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mx">RF, Wireless</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1882' id='mega-menu-item-1882'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mk">Semiconductors</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1883' id='mega-menu-item-1883'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9my">Sensors, Transducers</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-clear mega-menu-item-1884' id='mega-menu-item-1884'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mz">Test Products</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-columns-1-of-3 mega-menu-item-1885' id='mega-menu-item-1885'><a target="_blank" class="mega-menu-link" href="https://wtwh.me/9mA">Tools</a></li></ul> </li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-has-children mega-align-bottom-left mega-menu-flyout mega-menu-item-56062' id='mega-menu-item-56062'><a class="mega-menu-link" href="https://www.eeworldonline.com/learning-center" aria-expanded="false" tabindex="0">Learn<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-80114' id='mega-menu-item-80114'><a class="mega-menu-link" href="https://www.eeworldonline.com/category/tech-tips/">eBooks/Tech Tips</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-76567' id='mega-menu-item-76567'><a target="_blank" class="mega-menu-link" href="https://www.eeworldonline.com/design-guide-library">Design Guides</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-77221' id='mega-menu-item-77221'><a target="_blank" class="mega-menu-link" href="https://www.eeworldonline.com/learning-center">Learning Center</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-81739' id='mega-menu-item-81739'><a target="_blank" class="mega-menu-link" href="https://www.eeworldonline.com/category/tech-toolboxes/">Tech Toolboxes</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-80113' id='mega-menu-item-80113'><a class="mega-menu-link" href="https://gateway.on24.com/wcc/experience/elitewtwhmedia/2927718/4415581/eeworld">Webinars & Digital Events</a></li></ul> </li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-has-children mega-align-bottom-left mega-menu-flyout mega-menu-item-55895' id='mega-menu-item-55895'><a class="mega-menu-link" aria-expanded="false" tabindex="0">Resources<span class="mega-indicator"></span></a> <ul class="mega-sub-menu"> <li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-77693' id='mega-menu-item-77693'><a class="mega-menu-link" href="https://www.eeworldonline.com/category/digital-issues/">Digital Issues</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-77694' id='mega-menu-item-77694'><a class="mega-menu-link" href="https://eetrainingdays.com/">EE Training Days</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-55899' id='mega-menu-item-55899'><a target="_blank" class="mega-menu-link" href="https://www.eeworldonline.com/2023-leap-awards-winners-are-announced/">LEAP Awards</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-77695' id='mega-menu-item-77695'><a class="mega-menu-link" href="https://www.eeworldonline.com/category/podcasts/">Podcasts</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-77375' id='mega-menu-item-77375'><a target="_blank" class="mega-menu-link" href="https://www.eeworldonline.com/ee-world-webinars-and-digital-events/">Webinars / Digital Events</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-55898' id='mega-menu-item-55898'><a class="mega-menu-link" href="http://www.engineeringwhitepapers.com/category/electricalelectronic/">White Papers</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-62203' id='mega-menu-item-62203'><a class="mega-menu-link" href="https://www.designworldonline.com/category/news/engineering-diversity/">Engineering Diversity & Inclusion</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-menu-item-55896' id='mega-menu-item-55896'><a class="mega-menu-link" href="https://www.DesignFast.com">DesignFast</a></li></ul> </li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-align-bottom-left mega-menu-flyout mega-menu-item-80115' id='mega-menu-item-80115'><a class="mega-menu-link" href="https://www.engineersgarage.com/subscribe-engineers-garage-newsletter/" tabindex="0">Subscribe</a></li><li class='mega-menu-item mega-menu-item-type-custom mega-menu-item-object-custom mega-align-bottom-left mega-menu-flyout mega-menu-item-80423' id='mega-menu-item-80423'><a class="mega-menu-link" href="https://www.engineersgarage.com/join-us-as-a-guest-post-writer/" tabindex="0">Guest Post Guidelines</a></li><li class="menu-item search"><a href="#" class="search-toggle"><i class="icon-search"></i></a></li></ul></div></div></nav><div style="padding-top:10px;text-align:center"></div> <div style="padding-top:10px;text-align:center"><div id='jumbo-banner-ad-container' style='min-width: 970px; min-height: 90px;'><script>googletag.cmd.push(function() { googletag.display("jumbo-banner-ad-container"); });</script></div></div> <div class="site-inner"><div class="wrap"><div class="content-sidebar-wrap"><main class="content"><article class="type-post entry" aria-label="How to build an alcohol detector with the MQ3 gas sensor"><header class="entry-header"><h1 class="entry-title">How to build an alcohol detector with the MQ3 gas sensor</h1> <p class="entry-meta">By <span class="entry-author"><a href="https://www.engineersgarage.com/author/ayush-jain/" class="entry-author-link" rel="author"><span class="entry-author-name">Ayush Jain</span></a></span> <time class="entry-time">June 25, 2024</time> </p></header><div class="entry-content"><div class="addtoany_share_save_container addtoany_content addtoany_content_top"><div class="a2a_kit a2a_kit_size_16 addtoany_list" data-a2a-url="https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/" data-a2a-title="How to build an alcohol detector with the MQ3 gas sensor"><a class="a2a_button_facebook" href="https://www.addtoany.com/add_to/facebook?linkurl=https%3A%2F%2Fwww.engineersgarage.com%2Fhow-to-build-an-alcohol-detector-with-the-mq3-gas-sensor%2F&linkname=How%20to%20build%20an%20alcohol%20detector%20with%20the%20MQ3%20gas%20sensor" title="Facebook" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_x" href="https://www.addtoany.com/add_to/x?linkurl=https%3A%2F%2Fwww.engineersgarage.com%2Fhow-to-build-an-alcohol-detector-with-the-mq3-gas-sensor%2F&linkname=How%20to%20build%20an%20alcohol%20detector%20with%20the%20MQ3%20gas%20sensor" title="X" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_linkedin" href="https://www.addtoany.com/add_to/linkedin?linkurl=https%3A%2F%2Fwww.engineersgarage.com%2Fhow-to-build-an-alcohol-detector-with-the-mq3-gas-sensor%2F&linkname=How%20to%20build%20an%20alcohol%20detector%20with%20the%20MQ3%20gas%20sensor" title="LinkedIn" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_reddit" href="https://www.addtoany.com/add_to/reddit?linkurl=https%3A%2F%2Fwww.engineersgarage.com%2Fhow-to-build-an-alcohol-detector-with-the-mq3-gas-sensor%2F&linkname=How%20to%20build%20an%20alcohol%20detector%20with%20the%20MQ3%20gas%20sensor" title="Reddit" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_pinterest" href="https://www.addtoany.com/add_to/pinterest?linkurl=https%3A%2F%2Fwww.engineersgarage.com%2Fhow-to-build-an-alcohol-detector-with-the-mq3-gas-sensor%2F&linkname=How%20to%20build%20an%20alcohol%20detector%20with%20the%20MQ3%20gas%20sensor" title="Pinterest" rel="nofollow noopener" target="_blank"></a><a class="a2a_dd addtoany_share_save addtoany_share" href="https://www.addtoany.com/share"></a></div></div><p><span data-preserver-spaces="true">Depending on the country, as many as 25 to 35% of motor vehicle accidents happen because of drunk driving every year. When drivers consume alcohol, they not only put themselves at risk but others on the road. Fortunately, such accidents are preventable </span><span data-preserver-spaces="true">with a combination of</span><span data-preserver-spaces="true"> education, personal responsibility, and community efforts.</span></p> <p><span data-preserver-spaces="true">There are also systems that can</span><span data-preserver-spaces="true"> provide additional support. We’ll build one in this project.</span></p> <p><span data-preserver-spaces="true">This circuit design includes an alcohol detection device with an engine locking system. It uses the property of conductivity in an MQ3 alcohol gas sensor.</span></p> <h3><strong><span data-preserver-spaces="true">Working principle</span></strong></h3> <p><span data-preserver-spaces="true">The MQ3 alcohol gas sensor is developed from a material called </span><strong><span data-preserver-spaces="true">SnO2</span></strong><span data-preserver-spaces="true">, which detects alcohol gas. Connecting it to a microcontroller makes it possible to register the SnO2’s change in voltage output in the presence of alcohol. Thanks to a relay, a vehicle’s motor will automatically shut off based on the data from this sensor.</span></p> <p><strong><span data-preserver-spaces="true">Block diagram</span></strong></p> <div id="attachment_81298" style="width: 750px" class="wp-caption aligncenter"><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM.png"><img decoding="async" aria-describedby="caption-attachment-81298" class="size-large wp-image-81298" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM-1024x324.png" alt="" width="740" height="234" srcset="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM-1024x324.png 1024w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM-300x95.png 300w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM-768x243.png 768w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM-1536x486.png 1536w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM-368x116.png 368w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.50.07 PM.png 1740w" sizes="(max-width: 740px) 100vw, 740px" /></a><p id="caption-attachment-81298" class="wp-caption-text"><strong>Figure 1.</strong> Block diagram</p></div> <h3>Materials</h3> <ol> <li>Arduino UNO (or a similar microcontroller board)</li> <li>MQ-3 alcohol sensor</li> <li>5V relay</li> <li>LED</li> <li>Buzzer</li> <li>BC547 transistor</li> <li>Dual-shaft dc geared Mmotor 100 RPM</li> <li>Pushbutton switch</li> <li>Power supply (9-V battery or dc adapter)</li> <li>Breadboard and jumper wires</li> <li>Connecting cables</li> </ol> <h3><strong>Circuit diagram</strong></h3> <p> </p> <div id="attachment_81299" style="width: 750px" class="wp-caption aligncenter"><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor.jpg"><img decoding="async" aria-describedby="caption-attachment-81299" class="size-large wp-image-81299" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor-1024x657.jpg" alt="" width="740" height="475" srcset="https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor-1024x657.jpg 1024w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor-300x192.jpg 300w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor-768x493.jpg 768w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor-1536x985.jpg 1536w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor-368x236.jpg 368w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor-778x500.jpg 778w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Circuit-Diagram-of-alcohol-detection-system-using-MQ3-gas-sensor.jpg 1740w" sizes="(max-width: 740px) 100vw, 740px" /></a><p id="caption-attachment-81299" class="wp-caption-text"><strong>Figure 2.</strong> The circuit diagram of the alcohol detection system using an MQ3 gas sensor.</p></div> <h3><strong>Step-by-step guide</strong></h3> <p><strong>Step 1. The components<br /> </strong><span style="font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;">First gather all of the required materials and components. </span>Set up the Arduino UNO on a breadboard and connect the MQ-3 alcohol sensor, the relay module, and the switch according to the circuit diagram.</p> <div id="attachment_81300" style="width: 660px" class="wp-caption aligncenter"><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/Fig3-Alcohol-Sensor-Connections.png"><img loading="lazy" decoding="async" aria-describedby="caption-attachment-81300" class=" wp-image-81300" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/Fig3-Alcohol-Sensor-Connections-1024x634.png" alt="" width="650" height="402" srcset="https://www.engineersgarage.com/wp-content/uploads/2024/06/Fig3-Alcohol-Sensor-Connections-1024x634.png 1024w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Fig3-Alcohol-Sensor-Connections-300x186.png 300w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Fig3-Alcohol-Sensor-Connections-768x475.png 768w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Fig3-Alcohol-Sensor-Connections-368x228.png 368w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Fig3-Alcohol-Sensor-Connections.png 1112w" sizes="auto, (max-width: 650px) 100vw, 650px" /></a><p id="caption-attachment-81300" class="wp-caption-text"><strong>Figure 3. </strong> The alcohol sensor connections.</p></div> <div id="attachment_81301" style="width: 663px" class="wp-caption aligncenter"><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.57.08 PM.png"><img loading="lazy" decoding="async" aria-describedby="caption-attachment-81301" class=" wp-image-81301" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.57.08 PM-1024x633.png" alt="" width="653" height="403" srcset="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.57.08 PM-1024x633.png 1024w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.57.08 PM-300x185.png 300w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.57.08 PM-768x475.png 768w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.57.08 PM-368x228.png 368w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.57.08 PM.png 1074w" sizes="auto, (max-width: 653px) 100vw, 653px" /></a><p id="caption-attachment-81301" class="wp-caption-text"><strong>Figure 4.</strong> The LED and buzzer connections.</p></div> <div id="attachment_81302" style="width: 665px" class="wp-caption aligncenter"><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.58.22 PM.png"><img loading="lazy" decoding="async" aria-describedby="caption-attachment-81302" class="wp-image-81302 " src="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.58.22 PM-1024x571.png" alt="" width="655" height="365" srcset="https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.58.22 PM-1024x571.png 1024w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.58.22 PM-300x167.png 300w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.58.22 PM-768x429.png 768w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.58.22 PM-368x205.png 368w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Screenshot-2024-06-15-at-1.58.22 PM.png 1190w" sizes="auto, (max-width: 655px) 100vw, 655px" /></a><p id="caption-attachment-81302" class="wp-caption-text"><strong>Figure 5.</strong> The transistor circuit connections.</p></div> <p><strong>Step 2. Program Arduino</strong></p> <ul> <li>Ensure Arduino IDE is installed on your computer.</li> <li>Write the code for the alcohol levels from the MQ-3 sensor and display them on the LCD.</li> <li>Implement the logic to compare the alcohol levels with a predefined threshold.</li> <li>Program Arduino to control the relay module, which acts as the engine lock mechanism.</li> </ul> <p><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/The-code-alcohol-sensor.png"><img loading="lazy" decoding="async" class="aligncenter size-large wp-image-81306" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/The-code-alcohol-sensor-890x1024.png" alt="" width="740" height="851" srcset="https://www.engineersgarage.com/wp-content/uploads/2024/06/The-code-alcohol-sensor-890x1024.png 890w, https://www.engineersgarage.com/wp-content/uploads/2024/06/The-code-alcohol-sensor-261x300.png 261w, https://www.engineersgarage.com/wp-content/uploads/2024/06/The-code-alcohol-sensor-768x883.png 768w, https://www.engineersgarage.com/wp-content/uploads/2024/06/The-code-alcohol-sensor-207x238.png 207w, https://www.engineersgarage.com/wp-content/uploads/2024/06/The-code-alcohol-sensor.png 1198w" sizes="auto, (max-width: 740px) 100vw, 740px" /></a></p> <p><strong>Step 3. Calibrate the sensor</strong></p> <ul> <li>Power on Arduino and the alcohol sensor.</li> <li>Allow the sensor to warm up and then calibrate it by exposing it to clean air and recording the baseline value.</li> <li>Test the sensor with an alcohol source to ensure accurate readings.</li> </ul> <p>This is a cost-effective sensor with many uses, including alcohol alarms, portable detectors, and breathalyzers. It’s quite sensitive and typically offers a long lifespan.</p> <p><strong><span data-preserver-spaces="true">Step 4: </span><span data-preserver-spaces="true">demonstration<br /> </span></strong><span data-preserver-spaces="true">If no alcohol is detected, the vehicle’s motor will run normally. However, if the MQ3 sensor detects alcohol, it sends a signal to Arduino, which activates the buzzer and the LED. </span><span data-preserver-spaces="true">This alerts the motor via a circuit with a transistor and relay and will prevent the vehicle from turning on</span><span data-preserver-spaces="true">.</span></p> <div id="attachment_81303" style="width: 707px" class="wp-caption aligncenter"><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/Demonstration.jpg"><img loading="lazy" decoding="async" aria-describedby="caption-attachment-81303" class=" wp-image-81303" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/Demonstration-1024x767.jpg" alt="" width="697" height="522" srcset="https://www.engineersgarage.com/wp-content/uploads/2024/06/Demonstration-1024x767.jpg 1024w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Demonstration-300x225.jpg 300w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Demonstration-768x575.jpg 768w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Demonstration-318x238.jpg 318w, https://www.engineersgarage.com/wp-content/uploads/2024/06/Demonstration.jpg 1217w" sizes="auto, (max-width: 697px) 100vw, 697px" /></a><p id="caption-attachment-81303" class="wp-caption-text"><strong>Figure 6.</strong> The demonstration.</p></div> <h3><strong><span data-preserver-spaces="true">Conclusion</span></strong></h3> <p><span data-preserver-spaces="true">Following the above steps, you can create an Arduino-based alcohol detector with an engine lock, promoting safe driving practices. Remember to use this device responsibly and encourage others to do the same to stop preventable car accidents.</span></p> <h3><strong>Video</strong></h3> <div style="width: 678px;" class="wp-video"> <video class="wp-video-shortcode" id="video-81297-1" width="678" height="848" preload="metadata" controls="controls"><source type="video/mp4" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/WhatsApp-Video-2024-04-11-at-5.00.50-PM.mp4?_=1" /><a href="https://www.engineersgarage.com/wp-content/uploads/2024/06/WhatsApp-Video-2024-04-11-at-5.00.50-PM.mp4">https://www.engineersgarage.com/wp-content/uploads/2024/06/WhatsApp-Video-2024-04-11-at-5.00.50-PM.mp4</a></video></div> <p> </p> <div class="bawmrp"> <h3>You may also like:</h3> <ul> <li style="float:left;width:120px;height:auto;overflow:hidden;list-style:none;border-right: 1px solid #ccc;text-align:center;padding:0px 5px;" class="bawmrp_manual"><a href="https://www.engineersgarage.com/how-to-design-a-heart-rate-monitor-using-lora-and-arduino/"><img loading="lazy" decoding="async" width="100" height="100" src="https://www.engineersgarage.com/wp-content/uploads/2024/06/Heart-rate-mointor-LoRa-Rotator-150x150.jpg" class="attachment-100x100 size-100x100 wp-image-81259 wp-post-image" alt="" /><br />How to design a heart-rate monitor using LoRa and Arduino</a></li> <li style="float:left;width:120px;height:auto;overflow:hidden;list-style:none;border-right: 1px solid #ccc;text-align:center;padding:0px 5px;" class="bawmrp_manual"><a href="https://www.engineersgarage.com/how-to-design-an-automatic-streetlight-system-using-arduino/"><img loading="lazy" decoding="async" width="100" height="100" src="https://www.engineersgarage.com/wp-content/uploads/2024/05/ROTATOR-smart-street-light-circuit-150x150.jpg" class="attachment-100x100 size-100x100 wp-image-81055 wp-post-image" alt="" /><br />How to design an automatic streetlight system using Arduino</a></li> <li style="float:left;width:120px;height:auto;overflow:hidden;list-style:none;border-right: 1px solid #ccc;text-align:center;padding:0px 5px;" class="bawmrp_manual"><a href="https://www.engineersgarage.com/what-is-neuralink/"><img loading="lazy" decoding="async" width="100" height="100" src="https://www.engineersgarage.com/wp-content/uploads/2024/04/digitization-6389398_1280-150x150.jpg" class="attachment-100x100 size-100x100 wp-image-80989 wp-post-image" alt="" /><br />How Neuralink is providing a breakthrough in human-computer interface</a></li> <li style="float:left;width:120px;height:auto;overflow:hidden;list-style:none;border-right: 1px solid #ccc;text-align:center;padding:0px 5px;" class="bawmrp_manual"><a href="https://www.engineersgarage.com/what-are-the-sensors-used-in-self-driving-cars/"><img loading="lazy" decoding="async" width="100" height="100" src="https://www.engineersgarage.com/wp-content/uploads/2023/02/SensorCameraSelfDriving-150x150.png" class="attachment-100x100 size-100x100 wp-image-78194 wp-post-image" alt="" /><br />What are the sensors used in self-driving cars?</a></li> <li style="float:left;width:120px;height:auto;overflow:hidden;list-style:none;border-right: 1px solid #ccc;text-align:center;padding:0px 5px;" class="bawmrp_manual"><a href="https://www.engineersgarage.com/how-to-use-the-bme680-multi-purpose-sensor-with-arduino/"><img loading="lazy" decoding="async" width="100" height="100" src="https://www.engineersgarage.com/wp-content/uploads/2021/03/Screen-Shot-2021-03-24-at-5.08.05-PM-150x150.png" class="attachment-100x100 size-100x100 wp-image-63464 wp-post-image" alt="" srcset="https://www.engineersgarage.com/wp-content/uploads/2021/03/Screen-Shot-2021-03-24-at-5.08.05-PM-150x150.png 150w, https://www.engineersgarage.com/wp-content/uploads/2021/03/Screen-Shot-2021-03-24-at-5.08.05-PM-600x600.png 600w" sizes="auto, (max-width: 100px) 100vw, 100px" /><br />How to use the BME680 multi-purpose sensor with Arduino</a></li> <li style="float:left;width:120px;height:auto;overflow:hidden;list-style:none;border-right: 1px solid #ccc;text-align:center;padding:0px 5px;" class="bawmrp_manual"><a href="https://www.engineersgarage.com/how-a-driverless-car-sees-the-road/"><img loading="lazy" decoding="async" width="100" height="100" src="https://www.engineersgarage.com/wp-content/uploads/2019/07/Graphical-Diagram-Driverless-Car-150x150.png" class="attachment-100x100 size-100x100 wp-image-53771 wp-post-image" alt="" /><br />How a driverless car sees the road</a></li> <li style="float:left;width:120px;height:auto;overflow:hidden;list-style:none;border-right: 1px solid #ccc;text-align:center;padding:0px 5px;" class="bawmrp_manual"><a href="https://www.engineersgarage.com/how-wearable-electronics-transforming-healthcare/"><img loading="lazy" decoding="async" width="100" height="100" src="https://www.engineersgarage.com/wp-content/uploads/2019/10/featured-150x150.jpg" class="attachment-100x100 size-100x100 wp-image-60235 wp-post-image" alt="wearables" srcset="https://www.engineersgarage.com/wp-content/uploads/2019/10/featured-150x150.jpg 150w, https://www.engineersgarage.com/wp-content/uploads/2019/10/featured-600x600.jpg 600w" sizes="auto, (max-width: 100px) 100vw, 100px" /><br />How wearable electronics are transforming healthcare</a></li> </ul> </div> <div style="clear:both;"></div> <hr><span class="entry-categories">Filed Under: <a href="https://www.engineersgarage.com/circuit_design/" rel="category tag">Circuit Design</a>, <a href="https://www.engineersgarage.com/video/" rel="category tag">Video</a></span><br /><span class="entry-tags">Tagged With: <a href="https://www.engineersgarage.com/tag/accidents/" rel="tag">accidents</a>, <a href="https://www.engineersgarage.com/tag/alcoholdetector/" rel="tag">alcoholdetector</a>, <a href="https://www.engineersgarage.com/tag/arduino/" rel="tag">Arduino</a>, <a href="https://www.engineersgarage.com/tag/arduinouno/" rel="tag">arduinouno</a>, <a href="https://www.engineersgarage.com/tag/circuit/" rel="tag">circuit</a>, <a href="https://www.engineersgarage.com/tag/circuitdesign/" rel="tag">circuitdesign</a>, <a href="https://www.engineersgarage.com/tag/mq3sensor/" rel="tag">mq3sensor</a>, <a href="https://www.engineersgarage.com/tag/roadaccidents/" rel="tag">roadaccidents</a>, <a href="https://www.engineersgarage.com/tag/safedriving/" rel="tag">safedriving</a>, <a href="https://www.engineersgarage.com/tag/sensor/" rel="tag">sensor</a></span><br /> <hr><hr /> <nav class="navigation post-navigation" aria-label="Next Article"> <h2 class="screen-reader-text">Next Article</h2> <div class="nav-links"><div class="nav-previous"><a href="https://www.engineersgarage.com/trident-iot-introduces-chip-and-sdk-for-faster-iot-development-and-deployment/" rel="prev">← Previous Article</a></div><div class="nav-next"><a href="https://www.engineersgarage.com/lattice-semiconductor-addresses-security-threats-with-fpgas-and-software-stack/" rel="next">Next Article →</a></div></div> </nav><hr /></div><footer class="entry-footer"></footer></article> <div id="respond" class="comment-respond"> <h3 id="reply-title" class="comment-reply-title"><span style="font-size:16px">Questions related to this article?<br />👉Ask and discuss on <a href="https://edaboard.com?utm_source=EG&utm_medium=link&utm_campaign=TellUsWhatYouThink&utm_content=article81297&utm_term=forum" target="_blank" rel="nofollow noopener" style="color:red">EDAboard.com</a> and <a href="https://electro-tech-online.com?utm_source=EG&utm_medium=link&utm_campaign=TellUsWhatYouThink&utm_content=article81297&utm_term=forum" target="_blank" rel="nofollow noopener" style="color:red">Electro-Tech-Online.com</a> forums.</span><br /><br /><hr />Tell Us What You Think!! <small><a rel="nofollow" id="cancel-comment-reply-link" href="/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/#respond" style="display:none;">Cancel reply</a></small></h3><p class="must-log-in">You must be <a href="https://www.engineersgarage.com/login?spw_redirect=https://www.engineersgarage.com/how-to-build-an-alcohol-detector-with-the-mq3-gas-sensor/">logged in</a> to post a comment.</p> </div> <section id="custom_html-7" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><div class="textwidget custom-html-widget"></div></div></section> <section id="custom_html-8" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><div class="textwidget custom-html-widget"><center> <div style="display: flex; flex-direction: column; justify-content: center; width: 300px;"> <div align="center"><a href="https://www.engineersgarage.com/subscribe-engineers-garage-newsletter/" target="_blank"><img src="https://www.engineersgarage.com/wp-content/uploads/2023/03/EG-300x100-1.jpg" alt=“engineers garage newsletter”></a></div> <div align="center" style="width: 300px; line-height: 20px; padding-top: 10px;"><span style="font-weight: bold; color: #0c506d; text-align: center; font-size: 20px;">EXPAND YOUR KNOWLEDGE AND STAY CONNECTED</span></div> <div align="center" style="line-height: 16px; padding-top: 5px;"><span style="text-align: center; font-size: 16px;">Get the latest info on technologies, tools and strategies for EE professionals.</span></div> <div align="center" style="padding-top: 10px;"><a href="https://www.engineersgarage.com/subscribe-engineers-garage-newsletter/" target="_blank"><button style="background-color: #57bf9b; color: white; font-weight: bold; border: none; padding: 10px; font-size: 16px; cursor: pointer;">GET THE ENEWSLETTER</button></a></div> </div> </center></div></div></section> </main><aside class="sidebar sidebar-primary widget-area" role="complementary" aria-label="Primary Sidebar"><section id="search-2" class="widget widget_search"><div class="widget-wrap"><form class="search-form" method="get" action="https://www.engineersgarage.com/" role="search"><input class="search-form-input" type="search" name="s" id="searchform-1" placeholder="Search this website"><input class="search-form-submit" type="submit" value="GO"><meta content="https://www.engineersgarage.com/?s={s}"></form></div></section> <section id="custom_html-5" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><div class="textwidget custom-html-widget"><div align="center"> <div id='div-gpt-eg_sidebar1'> <script> googletag.cmd.push(function() { googletag.display('div-gpt-eg_sidebar1'); }); </script> </div> </div></div></div></section> <section id="custom_html-20" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><h4 class="widget-title widgettitle">EE TECH TOOLBOX</h4> <div class="textwidget custom-html-widget"><center> <div style="display: flex; flex-direction: column; justify-content: center; width: 300px;"> <div align="center"><a href="https://www.eeworldonline.com/tech-toolbox-connectivity/" target="_blank"><img src="https://www.eeworldonline.com/wp-content/uploads/2025/01/EE-TechToolbox-Connectors_Page_01-scaled.jpg" alt=“ee tech toolbox”></a></div> <div align="center" style="width: 300px; line-height: 20px; padding-top: 10px;"><span style="font-weight: bold; color: #0c506d; text-align: center; font-size: 20px;">Tech Toolbox: Connectivity</span></div> <div align="center" style="line-height: 16px; padding-top: 5px;"><span style="text-align: center; font-size: 16px;"> In this Tech Toolbox, we keep you connected to the connectivity technologies enabling Industry 4.0, AI/ML, and high-performance computing. Gain practical insights into selecting and implementing the right connector solutions. </span></div> <div align="center" style="padding-top: 10px;"><a href="https://www.eeworldonline.com/tech-toolbox-connectivity/" target="_blank"><button style="background-color: #57bf9b; color: white; font-weight: bold; border: none; padding: 10px; font-size: 16px; cursor: pointer;">Download PDF</button></a></div> <div align="center" style="padding-top: 10px;"><a href="https://www.eeworldonline.com/category/tech-toolboxes/" target="_blank"><button style="background-color: #57bf9b; color: white; font-weight: bold; border: none; padding: 10px; font-size: 16px; cursor: pointer;">View All Tech Toolboxes</button></a></div> </div> </center> </div></div></section> <section id="custom_html-14" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><h4 class="widget-title widgettitle">EE Learning Center</h4> <div class="textwidget custom-html-widget"><center><div style="display: flex; flex-direction: column; width: 270px;"><a href="https://www.eeworldonline.com/learning-center" target="_blank" rel="noopener"><img src="https://www.engineersgarage.com/wp-content/uploads/2024/08/300x250-2-EE-LearnCtr.png" alt="EE Learning Center" style="max-width: 270px;" /></a> </div> </center></div></div></section> <section id="custom_html-19" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><div class="textwidget custom-html-widget"><center> <div style="display: flex; flex-direction: column; justify-content: center; width: 300px;"> <div align="center"><a href="https://www.engineersgarage.com/subscribe-engineers-garage-newsletter/" target="_blank"><img src="https://www.engineersgarage.com/wp-content/uploads/2023/03/EG-300x100-1.jpg" alt=“engineers garage newsletter”></a></div> <div align="center" style="width: 300px; line-height: 20px; padding-top: 10px;"><span style="font-weight: bold; color: #0c506d; text-align: center; font-size: 20px;">EXPAND YOUR KNOWLEDGE AND STAY CONNECTED</span></div> <div align="center" style="line-height: 16px; padding-top: 5px;"><span style="text-align: center; font-size: 16px;">Get the latest info on technologies, tools and strategies for EE professionals.</span></div> <div align="center" style="padding-top: 10px;"><a href="https://www.engineersgarage.com/subscribe-engineers-garage-newsletter/" target="_blank"><button style="background-color: #57bf9b; color: white; font-weight: bold; border: none; padding: 10px; font-size: 16px; cursor: pointer;">GET THE ENEWSLETTER</button></a></div> </div> </center></div></div></section> <section id="custom_html-15" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><h4 class="widget-title widgettitle">HAVE A QUESTION?</h4> <div class="textwidget custom-html-widget"><div id="digital" style="padding: 0 15px 10px 15px;"> <span style="font-size: 12px;font-weight:bold"> Have a technical question about an article or other engineering questions? Check out our engineering forums <a href="https://www.edaboard.com" target="_blank" style="color:red">EDABoard.com</a> and <a href="https://www.electro-tech-online.com" target="_blank" style="color:red">Electro-Tech-Online.com</a> where you can get those questions asked and answered by your peers! </span> <br /> <br /> <div align="Center"> <div style="float: center;"><a href="https://www.edaboard.com/?utm_source=EG&utm_medium=widget&utm_campaign=question&utm_term=HaveQuestion" target="_blank" rel="nofollow"><button class="greenbutton">EDA Board</button></a></div> <br /> <div style="float: center;"><a href="https://www.electro-tech-online.com/?utm_source=EG&utm_medium=widget&utm_campaign=question&utm_term=HaveQuestion" target="_blank" rel="nofollow"><button class="greenbutton">Electro-Tech-Online</button></a></div> </div> </div> </div></div></section> <section id="rss-2" class="widget widget_rss"><div class="widget-wrap"><h4 class="widget-title widgettitle"><a class="rsswidget rss-widget-feed" href="http://www.edaboard.com/external.php?type=RSS"><img class="rss-widget-icon" style="border:0" width="14" height="14" src="https://www.engineersgarage.com/wp-includes/images/rss.png" alt="RSS" loading="lazy" /></a> <a class="rsswidget rss-widget-title" href="https://www.edaboard.com/">EDABOARD.com Discussions</a></h4> <ul><li><a class='rsswidget' href='https://www.edaboard.com/threads/please-help-me-identify-this-mosfet.414046/'>Please help me identify this mosfet.</a></li><li><a class='rsswidget' href='https://www.edaboard.com/threads/building-a-power-supply-for-my-project.414053/'>Building a Power Supply for My Project</a></li><li><a class='rsswidget' href='https://www.edaboard.com/threads/joining-two-devices-is-it-possible.413915/'>Joining Two Devices. Is it possible?</a></li><li><a class='rsswidget' href='https://www.edaboard.com/threads/am-i-supposed-to-make-a-symbol-for-this-schematic-i-copied-from-datasheet.414052/'>Am I supposed to make a symbol for this schematic I copied from datasheet?</a></li><li><a class='rsswidget' href='https://www.edaboard.com/threads/redirecting-high-ac-current-in-electrical-systems.414051/'>Redirecting High AC Current in Electrical Systems</a></li></ul></div></section> <section id="rss-3" class="widget widget_rss"><div class="widget-wrap"><h4 class="widget-title widgettitle"><a class="rsswidget rss-widget-feed" href="https://www.electro-tech-online.com/forums/-/index.rss"><img class="rss-widget-icon" style="border:0" width="14" height="14" src="https://www.engineersgarage.com/wp-includes/images/rss.png" alt="RSS" loading="lazy" /></a> <a class="rsswidget rss-widget-title" href="https://www.electro-tech-online.com/">Electro-Tech-Online.com Discussions</a></h4> <ul><li><a class='rsswidget' href='https://www.electro-tech-online.com/threads/how-to-identify-a-screen-part-for-repair.167334/'>How to identify a screen part for repair ?</a></li><li><a class='rsswidget' href='https://www.electro-tech-online.com/threads/rc-delay-for-opamp-input-how-to-calculate.167315/'>RC delay for opamp input: how to calculate</a></li><li><a class='rsswidget' href='https://www.electro-tech-online.com/threads/funny-images-thread.130358/'>Funny Images Thread!</a></li><li><a class='rsswidget' href='https://www.electro-tech-online.com/threads/infrared-sensor-array-to-detect-mosquito-entry.167320/'>Infrared sensor array to detect mosquito entry</a></li><li><a class='rsswidget' href='https://www.electro-tech-online.com/threads/datasheet-for-led-filament.167312/'>Datasheet for LED filament</a></li></ul></div></section> <section id="category-posts-2" class="widget cat-post-widget"><div class="widget-wrap"><h4 class="widget-title widgettitle">Featured – EMI/EMC Series</h4> <ul id="category-posts-2-internal" class="category-posts-internal"> <li class='cat-post-item'><div><a class="cat-post-thumbnail cat-post-dark" href="https://www.engineersgarage.com/what-is-emc/" title="What is EMC?"><span class="cat-post-crop cat-post-format cat-post-format-standard"><img width="150" height="95" src="https://www.engineersgarage.com/wp-content/uploads/2022/01/EMC-featured-1.jpg" class="attachment- size- wp-image-65587 wp-post-image" alt="" data-cat-posts-width="150" data-cat-posts-height="95" decoding="async" loading="lazy" srcset="https://www.engineersgarage.com/wp-content/uploads/2022/01/EMC-featured-1.jpg 944w, https://www.engineersgarage.com/wp-content/uploads/2022/01/EMC-featured-1-300x159.jpg 300w, https://www.engineersgarage.com/wp-content/uploads/2022/01/EMC-featured-1-768x407.jpg 768w, https://www.engineersgarage.com/wp-content/uploads/2022/01/EMC-featured-1-368x195.jpg 368w" sizes="auto, (max-width: 150px) 100vw, 150px" /></span></a> <h6 class="widget-title"><a class="cat-post-title" href="https://www.engineersgarage.com/what-is-emc/" rel="bookmark">What is EMC?</a></h6></div></li><li class='cat-post-item'><div><a class="cat-post-thumbnail cat-post-dark" href="https://www.engineersgarage.com/what-are-the-ems-emc-immunity-lab-tests/" title="What are EMS/EMC immunity lab tests?"><span class="cat-post-crop cat-post-format cat-post-format-standard"><img width="150" height="95" src="https://www.engineersgarage.com/wp-content/uploads/2022/01/1Block-diagram-of-EMC-immunity-test.jpg" class="attachment- size- wp-image-65846 wp-post-image" alt="" data-cat-posts-width="150" data-cat-posts-height="95" decoding="async" loading="lazy" srcset="https://www.engineersgarage.com/wp-content/uploads/2022/01/1Block-diagram-of-EMC-immunity-test.jpg 801w, https://www.engineersgarage.com/wp-content/uploads/2022/01/1Block-diagram-of-EMC-immunity-test-300x225.jpg 300w, https://www.engineersgarage.com/wp-content/uploads/2022/01/1Block-diagram-of-EMC-immunity-test-768x576.jpg 768w, https://www.engineersgarage.com/wp-content/uploads/2022/01/1Block-diagram-of-EMC-immunity-test-317x238.jpg 317w" sizes="auto, (max-width: 150px) 100vw, 150px" /></span></a> <h6 class="widget-title"><a class="cat-post-title" href="https://www.engineersgarage.com/what-are-the-ems-emc-immunity-lab-tests/" rel="bookmark">What are EMS/EMC immunity lab tests?</a></h6></div></li><li class='cat-post-item'><div><a class="cat-post-thumbnail cat-post-dark" href="https://www.engineersgarage.com/some-common-emi-emc-tests/" title="What are some common EMI/EMC tests?"><span class="cat-post-crop cat-post-format cat-post-format-standard"><img width="150" height="95" src="https://www.engineersgarage.com/wp-content/uploads/2022/01/dreamstime_s_150541257.jpg" class="attachment- size- wp-image-65707 wp-post-image" alt="" data-cat-posts-width="150" data-cat-posts-height="95" decoding="async" loading="lazy" srcset="https://www.engineersgarage.com/wp-content/uploads/2022/01/dreamstime_s_150541257.jpg 800w, https://www.engineersgarage.com/wp-content/uploads/2022/01/dreamstime_s_150541257-300x225.jpg 300w, https://www.engineersgarage.com/wp-content/uploads/2022/01/dreamstime_s_150541257-768x576.jpg 768w, https://www.engineersgarage.com/wp-content/uploads/2022/01/dreamstime_s_150541257-317x238.jpg 317w" sizes="auto, (max-width: 150px) 100vw, 150px" /></span></a> <h6 class="widget-title"><a class="cat-post-title" href="https://www.engineersgarage.com/some-common-emi-emc-tests/" rel="bookmark">What are some common EMI/EMC tests?</a></h6></div></li><li class='cat-post-item'><div><a class="cat-post-thumbnail cat-post-dark" href="https://www.engineersgarage.com/how-to-perform-an-emi-emc-pre-compliance-test/" title="How to perform an EMI/EMC pre-compliance test"><span class="cat-post-crop cat-post-format cat-post-format-standard"><img width="150" height="95" src="https://www.engineersgarage.com/wp-content/uploads/2022/02/3E-field-electric-field-and-H-field-magnetic-field.jpg" class="attachment- size- wp-image-65943 wp-post-image" alt="" data-cat-posts-width="150" data-cat-posts-height="95" decoding="async" loading="lazy" srcset="https://www.engineersgarage.com/wp-content/uploads/2022/02/3E-field-electric-field-and-H-field-magnetic-field.jpg 1814w, https://www.engineersgarage.com/wp-content/uploads/2022/02/3E-field-electric-field-and-H-field-magnetic-field-300x141.jpg 300w, https://www.engineersgarage.com/wp-content/uploads/2022/02/3E-field-electric-field-and-H-field-magnetic-field-1024x482.jpg 1024w, https://www.engineersgarage.com/wp-content/uploads/2022/02/3E-field-electric-field-and-H-field-magnetic-field-768x361.jpg 768w, https://www.engineersgarage.com/wp-content/uploads/2022/02/3E-field-electric-field-and-H-field-magnetic-field-1536x722.jpg 1536w, https://www.engineersgarage.com/wp-content/uploads/2022/02/3E-field-electric-field-and-H-field-magnetic-field-368x173.jpg 368w" sizes="auto, (max-width: 150px) 100vw, 150px" /></span></a> <h6 class="widget-title"><a class="cat-post-title" href="https://www.engineersgarage.com/how-to-perform-an-emi-emc-pre-compliance-test/" rel="bookmark">How to perform an EMI/EMC pre-compliance test</a></h6></div></li><li class='cat-post-item'><div><a class="cat-post-thumbnail cat-post-dark" href="https://www.engineersgarage.com/ems-emc-pre-compliance-immunity-test/" title="EMS/EMC Pre-Compliance immunity test"><span class="cat-post-crop cat-post-format cat-post-format-standard"><img width="150" height="95" src="https://www.engineersgarage.com/wp-content/uploads/2022/03/6TEM-cell-for-immunity-test-768x438-1.png" class="attachment- size- wp-image-71059 wp-post-image" alt="" data-cat-posts-width="150" data-cat-posts-height="95" decoding="async" loading="lazy" srcset="https://www.engineersgarage.com/wp-content/uploads/2022/03/6TEM-cell-for-immunity-test-768x438-1.png 768w, https://www.engineersgarage.com/wp-content/uploads/2022/03/6TEM-cell-for-immunity-test-768x438-1-300x171.png 300w, https://www.engineersgarage.com/wp-content/uploads/2022/03/6TEM-cell-for-immunity-test-768x438-1-368x210.png 368w" sizes="auto, (max-width: 150px) 100vw, 150px" /></span></a> <h6 class="widget-title"><a class="cat-post-title" href="https://www.engineersgarage.com/ems-emc-pre-compliance-immunity-test/" rel="bookmark">EMS/EMC Pre-Compliance immunity test</a></h6></div></li><li class='cat-post-item'><div><a class="cat-post-thumbnail cat-post-dark" href="https://www.engineersgarage.com/non-invasive-current-sensor-with-arduino/" title="Non-invasive current sensor with Arduino"><span class="cat-post-crop cat-post-format cat-post-format-standard"><img width="150" height="95" src="https://www.engineersgarage.com/wp-content/uploads/2021/04/current-sensor-figure-1.jpg" class="attachment- size- wp-image-63609 wp-post-image" alt="" data-cat-posts-width="150" data-cat-posts-height="95" decoding="async" loading="lazy" srcset="https://www.engineersgarage.com/wp-content/uploads/2021/04/current-sensor-figure-1.jpg 624w, https://www.engineersgarage.com/wp-content/uploads/2021/04/current-sensor-figure-1-300x212.jpg 300w, https://www.engineersgarage.com/wp-content/uploads/2021/04/current-sensor-figure-1-338x238.jpg 338w" sizes="auto, (max-width: 150px) 100vw, 150px" /></span></a> <h6 class="widget-title"><a class="cat-post-title" href="https://www.engineersgarage.com/non-invasive-current-sensor-with-arduino/" rel="bookmark">Non-invasive current sensor with Arduino</a></h6></div></li></ul> </div></section> <section id="recent-posts-2" class="widget widget_recent_entries"><div class="widget-wrap"> <h4 class="widget-title widgettitle">Recent Articles</h4> <ul> <li> <a href="https://www.engineersgarage.com/how-to-setup-headless-raspberry-pi-for-remote-access-using-ssh-and-vnc/">How to setup headless Raspberry Pi for remote access using SSH and VNC</a> </li> <li> <a href="https://www.engineersgarage.com/infineons-multi-rail-power-ic-fits-48-pin-package/">Infineon’s multi-rail power IC fits 48-pin package</a> </li> <li> <a href="https://www.engineersgarage.com/seco-introduces-modular-interface-solution/">Seco introduces modular interface solution</a> </li> <li> <a href="https://www.engineersgarage.com/conformable-cables-from-amphenol-rf-enhance-microwave-connections/">Conformable cables from Amphenol RF enhance microwave connections</a> </li> <li> <a href="https://www.engineersgarage.com/1-0-x-0-6-mm-protection-diodes-meet-open-alliance-specs/">1.0 x 0.6 mm protection diodes meet OPEN Alliance specs</a> </li> </ul> </div></section> <section id="custom_html-3" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><div class="textwidget custom-html-widget"> <div id='div-gpt-eg_sidebarbottom'> <script> googletag.cmd.push(function() { googletag.display('div-gpt-eg_sidebarbottom'); }); </script> </div> </div></div></section> <section id="custom_html-18" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><h4 class="widget-title widgettitle">EE ENGINEERING TRAINING DAYS</h4> <div class="textwidget custom-html-widget"><center><div style="display: flex; flex-direction: column; width: 270px;"><a href="https://eetrainingdays.com/" target="_blank" rel="noopener"><img src="https://www.eeworldonline.com/wp-content/uploads/2024/12/300x250-side-bar-graphic.png" alt="engineering" /></a> </div> </center></div></div></section> <section id="custom_html-17" class="widget_text widget widget_custom_html"><div class="widget_text widget-wrap"><h4 class="widget-title widgettitle">Submit a Guest Post</h4> <div class="textwidget custom-html-widget"><center> <a href="/join-us-as-a-guest-post-writer/"> <img src="/wp-content/uploads/2022/10/guest-post-banner.jpg" alt="submit a guest post"> </a> </center></div></div></section> </aside></div></div></div><div class="footer-socials"><div class="wrap"><label style="color:#ffffff">Connect with Engineers Garage</label> <a href="https://www.facebook.com/engineersgarage" target="_blank" rel="noopener noreferrer"><i class="icon-facebook"></i></a><a href="https://twitter.com/EngineersGarage" target="_blank" rel="noopener noreferrer"><i class="icon-twitter"></i></a><a href="https://www.youtube.com/@engineersgarage" target="_blank" rel="noopener noreferrer"><i class="icon-youtube"></i></a></div></div><footer class="site-footer"><div class="wrap"><div class="row"><div class="footer-logo"><a href="https://www.engineersgarage.com">Engineers Garage</a></div><div class="footer-menu"><div class="menu-footer-nav-container"><ul id="menu-footer-nav" class="menu"><li id="menu-item-55876" class="menu-item"><a target="_blank" href="http://www.analogictips.com/">Analog IC TIps</a></li> <li id="menu-item-55877" class="menu-item"><a target="_blank" href="https://www.connectortips.com/">Connector Tips</a></li> <li id="menu-item-80507" class="menu-item"><a href="https://www.batterypowertips.com/">Battery Power Tips</a></li> <li id="menu-item-55872" class="menu-item"><a target="_blank" href="https://www.DesignFast.com/">DesignFast</a></li> <li id="menu-item-55873" class="menu-item"><a target="_blank" href="http://www.edaboard.com/">EDABoard Forums</a></li> <li id="menu-item-55881" class="menu-item"><a target="_blank" href="https://www.eeworldonline.com">EE World Online</a></li> <li id="menu-item-55874" class="menu-item"><a target="_blank" href="http://www.electro-tech-online.com/">Electro-Tech-Online Forums</a></li> <li id="menu-item-79699" class="menu-item"><a target="_blank" href="https://www.evengineeringonline.com/">EV Engineering</a></li> <li id="menu-item-55875" class="menu-item"><a target="_blank" href="http://www.microcontrollertips.com/">Microcontroller Tips</a></li> <li id="menu-item-55878" class="menu-item"><a target="_blank" href="http://www.powerelectronictips.com/">Power Electronic Tips</a></li> <li id="menu-item-55879" class="menu-item"><a target="_blank" href="http://www.sensortips.com/">Sensor Tips</a></li> <li id="menu-item-55880" class="menu-item"><a target="_blank" href="http://www.testandmeasurementtips.com/">Test and Measurement Tips</a></li> <li id="menu-item-60429" class="menu-item"><a target="_blank" href="https://www.5gtechnologyworld.com/">5G Technology World</a></li> <li id="menu-item-79962" class="menu-item"><a href="https://www.engineersgarage.com/subscribe-engineers-garage-newsletter/">Subscribe to our newsletter</a></li> <li id="menu-item-55885" class="menu-item"><a href="https://www.engineersgarage.com/about-us/">About Us</a></li> <li id="menu-item-55886" class="menu-item"><a href="https://www.engineersgarage.com/contact-us/">Contact Us</a></li> <li id="menu-item-55887" class="menu-item"><a target="_blank" href="https://marketing.wtwhmedia.com/2024-ee-world-online-media-guide/">Advertise</a></li> </ul></div></div><div class="footer-copyright"><p>Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media<br /> <a href="http://www.wtwhmedia.com/privacy-policy/" target="_blank">Privacy Policy</a> </p></div></div></div></footer></div><div class="site-search"><div class="wrap"><div class="search-inner"><h2>Search Engineers Garage</h2><form class="search-form" method="get" action="https://www.engineersgarage.com/" role="search"><input class="search-form-input" type="search" name="s" id="searchform-2" placeholder="Search this website"><input class="search-form-submit" type="submit" value="GO"><meta content="https://www.engineersgarage.com/?s={s}"></form></div></div></div> <script type="text/javascript"> function genesisBlocksShare( url, title, w, h ){ var left = ( window.innerWidth / 2 )-( w / 2 ); var top = ( window.innerHeight / 2 )-( h / 2 ); return window.open(url, title, 'toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=no, resizable=no, copyhistory=no, width=600, height=600, top='+top+', left='+left); } </script>  <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-MMC9PJ9" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>   <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-NJMRR6Z" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>  <div id='div-gpt-eg_wallpaper'> <script> googletag.cmd.push(function() { googletag.display('div-gpt-eg_wallpaper'); }); </script> </div> <div id='div-gpt-eg_allstreamflex'> <script> googletag.cmd.push(function() { googletag.display('div-gpt-eg_allstreamflex'); }); </script> </div> <div id='div-gpt-eg_allstreamprelude'> <script> googletag.cmd.push(function() { googletag.display('div-gpt-eg_allstreamprelude'); }); </script> </div> <div id="sidr-mobile-menu" class="sidr right"><a class="sidr-menu-close" href="#"><i class="icon-close"></i></a><div class="menu-main-nav-container"><ul id="menu-main-nav" class="menu"><li id="menu-item-61908" class="menu-item menu-item-has-children"><a href="https://www.engineersgarage.com/projects-and-tutorials/">Electronics Projects and Tutorials</a> <ul class="sub-menu"> <li id="menu-item-39808" class="menu-item menu-item-has-children"><a href="https://www.engineersgarage.com/electronic-projects/">Electronic Projects</a> <ul class="sub-menu"> <li id="menu-item-81272" class="menu-item"><a href="https://www.engineersgarage.com/arduino/">Arduino Projects</a></li> <li id="menu-item-81273" class="menu-item"><a href="https://www.engineersgarage.com/electronic-projects/avr/">AVR</a></li> <li id="menu-item-80793" class="menu-item"><a href="https://www.engineersgarage.com/raspberry-pi-electronic-projects/">Raspberry pi</a></li> <li id="menu-item-78430" class="menu-item"><a href="https://www.engineersgarage.com/electronic-projects/esp8266-electronic-projects/">ESP8266</a></li> <li id="menu-item-78434" class="menu-item"><a href="https://www.engineersgarage.com/electronic-projects/beaglebone-electronic-projects/">BeagleBone</a></li> <li id="menu-item-80794" class="menu-item"><a href="https://www.engineersgarage.com/electronic-projects/8051-microcontroller/">8051 Microcontroller</a></li> <li id="menu-item-55864" class="menu-item"><a href="https://www.engineersgarage.com/electronic-projects/arm-electronic-projects-electronic-projects/">ARM</a></li> <li id="menu-item-80795" class="menu-item"><a href="https://www.engineersgarage.com/electronic-projects/pic-microcontroller-electronic-projects/">PIC Microcontroller</a></li> <li id="menu-item-60239" class="menu-item"><a href="https://www.engineersgarage.com/electronic-projects/stm32-electronic-projects-electronic-projects/">STM32</a></li> </ul> </li> <li id="menu-item-7268" class="menu-item menu-item-has-children"><a href="https://www.engineersgarage.com/tutorials/">Tutorials</a> <ul class="sub-menu"> <li id="menu-item-78818" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/audio-tutorials/">Audio Electronics</a></li> <li id="menu-item-78819" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/battery-management-systems/">Battery Management</a></li> <li id="menu-item-78820" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/brainwave/">Brainwave</a></li> <li id="menu-item-78833" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/evs/">Electric Vehicles</a></li> <li id="menu-item-78822" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/emc-emi/">EMI/EMC/RFI</a></li> <li id="menu-item-78823" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/filters/">Hardware Filters</a></li> <li id="menu-item-78826" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/iot-tutorials/">IoT tutorials</a></li> <li id="menu-item-80151" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/power/">Power Tutorials</a></li> <li id="menu-item-78835" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/python/">Python</a></li> <li id="menu-item-78829" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/sensors-tutorials/">Sensors</a></li> <li id="menu-item-78830" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/usb/">USB</a></li> <li id="menu-item-78832" class="menu-item"><a href="https://www.engineersgarage.com/tutorials/vhdl-tutorials/">VHDL</a></li> </ul> </li> <li id="menu-item-56096" class="menu-item"><a href="https://www.engineersgarage.com/circuit_design/">Circuit Design</a></li> <li id="menu-item-62725" class="menu-item"><a target="_blank" href="https://www.youtube.com/user/engineersgarage">Project Videos</a></li> <li id="menu-item-7269" class="menu-item"><a href="https://www.engineersgarage.com/components/">Components</a></li> </ul> </li> <li id="menu-item-39810" class="menu-item menu-item-has-children"><a href="https://www.engineersgarage.com/article_page/">Articles</a> <ul class="sub-menu"> <li id="menu-item-63122" class="menu-item"><a href="https://www.engineersgarage.com/tech-articles/">Tech Articles</a></li> <li id="menu-item-13371" class="menu-item"><a href="https://www.engineersgarage.com/insight/">Insight</a></li> <li id="menu-item-13399" class="menu-item"><a href="https://www.engineersgarage.com/invention-stories/">Invention Stories</a></li> <li id="menu-item-13326" class="menu-item"><a href="https://www.engineersgarage.com/how_to/">How to</a></li> <li id="menu-item-59366" class="menu-item"><a href="https://www.engineersgarage.com/what_is/">What Is</a></li> </ul> </li> <li id="menu-item-1863" class="menu-item menu-item-has-children"><a href="#">News</a> <ul class="sub-menu"> <li id="menu-item-39809" class="menu-item"><a href="https://www.engineersgarage.com/news/">Electronic Product News</a></li> <li id="menu-item-77696" class="menu-item"><a href="https://www.engineersgarage.com/news/business-news/">Business News</a></li> <li id="menu-item-77697" class="menu-item"><a href="https://www.engineersgarage.com/news/company-start-up-news/">Company/Start-up News</a></li> <li id="menu-item-14489" class="menu-item"><a href="https://www.engineersgarage.com/reviews/">DIY Reviews</a></li> <li id="menu-item-14287" class="menu-item"><a href="https://www.engineersgarage.com/guest_post/">Guest Post</a></li> </ul> </li> <li id="menu-item-55871" class="menu-item menu-item-has-children"><a>Forums</a> <ul class="sub-menu"> <li id="menu-item-55870" class="menu-item"><a href="https://www.edaboard.com/">EDABoard.com</a></li> <li id="menu-item-55869" class="menu-item"><a href="https://www.electro-tech-online.com/">Electro-Tech-Online</a></li> <li id="menu-item-1851" class="menu-item"><a href="https://forums.engineersgarage.com/">EG Forum Archive</a></li> </ul> </li> <li id="menu-item-1868" class="menu-item menu-item-has-children"><a target="_blank" href="https://wtwh.me/9mk">DigiKey Store</a> <ul class="sub-menu"> <li id="menu-item-1869" class="menu-item"><a target="_blank" href="https://wtwh.me/9ml">Cables, Wires</a></li> <li id="menu-item-1870" class="menu-item"><a target="_blank" href="https://wtwh.me/9mm">Connectors, Interconnect</a></li> <li id="menu-item-1871" class="menu-item"><a target="_blank" href="https://wtwh.me/9mn">Discrete</a></li> <li id="menu-item-1872" class="menu-item"><a target="_blank" href="https://wtwh.me/9mo">Electromechanical</a></li> <li id="menu-item-1873" class="menu-item"><a target="_blank" href="https://wtwh.me/9mp">Embedded Computers</a></li> <li id="menu-item-1874" class="menu-item"><a target="_blank" href="https://wtwh.me/9mq">Enclosures, Hardware, Office</a></li> <li id="menu-item-1875" class="menu-item"><a target="_blank" href="https://wtwh.me/9mr">Integrated Circuits (ICs)</a></li> <li id="menu-item-1876" class="menu-item"><a target="_blank" href="https://wtwh.me/9ms">Isolators</a></li> <li id="menu-item-1877" class="menu-item"><a target="_blank" href="https://wtwh.me/9mt">LED/Optoelectronics</a></li> <li id="menu-item-1878" class="menu-item"><a target="_blank" href="https://wtwh.me/9mu">Passive</a></li> <li id="menu-item-1879" class="menu-item"><a target="_blank" href="https://wtwh.me/9mv">Power, Circuit Protection</a></li> <li id="menu-item-1880" class="menu-item"><a target="_blank" href="https://wtwh.me/9mw">Programmers</a></li> <li id="menu-item-1881" class="menu-item"><a target="_blank" href="https://wtwh.me/9mx">RF, Wireless</a></li> <li id="menu-item-1882" class="menu-item"><a target="_blank" href="https://wtwh.me/9mk">Semiconductors</a></li> <li id="menu-item-1883" class="menu-item"><a target="_blank" href="https://wtwh.me/9my">Sensors, Transducers</a></li> <li id="menu-item-1884" class="menu-item"><a target="_blank" href="https://wtwh.me/9mz">Test Products</a></li> <li id="menu-item-1885" class="menu-item"><a target="_blank" href="https://wtwh.me/9mA">Tools</a></li> </ul> </li> <li id="menu-item-56062" class="menu-item menu-item-has-children"><a href="https://www.eeworldonline.com/learning-center">Learn</a> <ul class="sub-menu"> <li id="menu-item-80114" class="menu-item"><a href="https://www.eeworldonline.com/category/tech-tips/">eBooks/Tech Tips</a></li> <li id="menu-item-76567" class="menu-item"><a target="_blank" href="https://www.eeworldonline.com/design-guide-library">Design Guides</a></li> <li id="menu-item-77221" class="menu-item"><a target="_blank" href="https://www.eeworldonline.com/learning-center">Learning Center</a></li> <li id="menu-item-81739" class="menu-item"><a target="_blank" href="https://www.eeworldonline.com/category/tech-toolboxes/">Tech Toolboxes</a></li> <li id="menu-item-80113" class="menu-item"><a href="https://gateway.on24.com/wcc/experience/elitewtwhmedia/2927718/4415581/eeworld">Webinars & Digital Events</a></li> </ul> </li> <li id="menu-item-55895" class="menu-item menu-item-has-children"><a>Resources</a> <ul class="sub-menu"> <li id="menu-item-77693" class="menu-item"><a href="https://www.eeworldonline.com/category/digital-issues/">Digital Issues</a></li> <li id="menu-item-77694" class="menu-item"><a href="https://eetrainingdays.com/">EE Training Days</a></li> <li id="menu-item-55899" class="menu-item"><a target="_blank" href="https://www.eeworldonline.com/2023-leap-awards-winners-are-announced/">LEAP Awards</a></li> <li id="menu-item-77695" class="menu-item"><a href="https://www.eeworldonline.com/category/podcasts/">Podcasts</a></li> <li id="menu-item-77375" class="menu-item"><a target="_blank" href="https://www.eeworldonline.com/ee-world-webinars-and-digital-events/">Webinars / Digital Events</a></li> <li id="menu-item-55898" class="menu-item"><a href="http://www.engineeringwhitepapers.com/category/electricalelectronic/">White Papers</a></li> <li id="menu-item-62203" class="menu-item"><a href="https://www.designworldonline.com/category/news/engineering-diversity/">Engineering Diversity & Inclusion</a></li> <li id="menu-item-55896" class="menu-item"><a href="https://www.DesignFast.com">DesignFast</a></li> </ul> </li> <li id="menu-item-80115" class="menu-item"><a href="https://www.engineersgarage.com/subscribe-engineers-garage-newsletter/">Subscribe</a></li> <li id="menu-item-80423" class="menu-item"><a href="https://www.engineersgarage.com/join-us-as-a-guest-post-writer/">Guest Post Guidelines</a></li> </ul></div></div></div><style type="text/css" media="screen"></style><link rel='stylesheet' id='mediaelement-css' href='https://www.engineersgarage.com/wp-includes/js/mediaelement/mediaelementplayer-legacy.min.css?ver=4.2.17' type='text/css' media='all' /> <link rel='stylesheet' id='wp-mediaelement-css' href='https://www.engineersgarage.com/wp-includes/js/mediaelement/wp-mediaelement.min.css?ver=6.7.2' type='text/css' media='all' /> <script type="text/javascript" src="https://www.engineersgarage.com/wp-content/plugins/genesis-blocks/dist/assets/js/dismiss.js?ver=1732716289" id="genesis-blocks-dismiss-js-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/comment-reply.min.js?ver=6.7.2" id="comment-reply-js" async="async" data-wp-strategy="async"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-content/themes/ThemeWTWHv2/assets/js/global-min.js?ver=1629218360" id="ea-global-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/jquery/ui/core.min.js?ver=1.13.3" id="jquery-ui-core-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/jquery/ui/tabs.min.js?ver=1.13.3" id="jquery-ui-tabs-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/hoverIntent.min.js?ver=1.10.2" id="hoverIntent-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-content/plugins/megamenu/js/maxmegamenu.js?ver=3.4.1" id="megamenu-js"></script> <script type="text/javascript" id="wtwh-uni-gam-prestitial-core-js-extra"> /* <![CDATA[ */ var PRESTITIALINFO = {"logoHeight":"100","logoWidth":"100","backgroundColor":"clear","siteUrl":"https:\/\/www.engineersgarage.com","siteName":"Engineers Garage","siteLogo":"svg","mainCss":"https:\/\/www.engineersgarage.com\/wp-content\/plugins\/wtwh-universal-gam\/assets\/css\/frontend\/prestitial\/main.css?=1.1.1","prestitialCss":"https:\/\/www.engineersgarage.com\/wp-content\/plugins\/wtwh-universal-gam\/assets\/css\/frontend\/prestitial\/prestitial.css?=1.1.1"}; /* ]]> */ </script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-content/plugins/wtwh-universal-gam/assets/js/frontend/prestitial/adlogic.js?ver=1.1.1" id="wtwh-uni-gam-prestitial-core-js"></script> <script type="text/javascript" async data-no-optimize="1" src="https://www.engineersgarage.com/wp-content/plugins/perfmatters/vendor/instant-page/pminstantpage.min.js?ver=2.3.9" id="perfmatters-instant-page-js"></script> <script type="text/javascript" id="mediaelement-core-js-before"> /* <![CDATA[ */ var mejsL10n = {"language":"en","strings":{"mejs.download-file":"Download File","mejs.install-flash":"You are using a browser that does not have Flash player enabled or installed. Please turn on your Flash player plugin or download the latest version from https:\/\/get.adobe.com\/flashplayer\/","mejs.fullscreen":"Fullscreen","mejs.play":"Play","mejs.pause":"Pause","mejs.time-slider":"Time Slider","mejs.time-help-text":"Use Left\/Right Arrow keys to advance one second, Up\/Down arrows to advance ten seconds.","mejs.live-broadcast":"Live Broadcast","mejs.volume-help-text":"Use Up\/Down Arrow keys to increase or decrease volume.","mejs.unmute":"Unmute","mejs.mute":"Mute","mejs.volume-slider":"Volume Slider","mejs.video-player":"Video Player","mejs.audio-player":"Audio Player","mejs.captions-subtitles":"Captions\/Subtitles","mejs.captions-chapters":"Chapters","mejs.none":"None","mejs.afrikaans":"Afrikaans","mejs.albanian":"Albanian","mejs.arabic":"Arabic","mejs.belarusian":"Belarusian","mejs.bulgarian":"Bulgarian","mejs.catalan":"Catalan","mejs.chinese":"Chinese","mejs.chinese-simplified":"Chinese (Simplified)","mejs.chinese-traditional":"Chinese (Traditional)","mejs.croatian":"Croatian","mejs.czech":"Czech","mejs.danish":"Danish","mejs.dutch":"Dutch","mejs.english":"English","mejs.estonian":"Estonian","mejs.filipino":"Filipino","mejs.finnish":"Finnish","mejs.french":"French","mejs.galician":"Galician","mejs.german":"German","mejs.greek":"Greek","mejs.haitian-creole":"Haitian Creole","mejs.hebrew":"Hebrew","mejs.hindi":"Hindi","mejs.hungarian":"Hungarian","mejs.icelandic":"Icelandic","mejs.indonesian":"Indonesian","mejs.irish":"Irish","mejs.italian":"Italian","mejs.japanese":"Japanese","mejs.korean":"Korean","mejs.latvian":"Latvian","mejs.lithuanian":"Lithuanian","mejs.macedonian":"Macedonian","mejs.malay":"Malay","mejs.maltese":"Maltese","mejs.norwegian":"Norwegian","mejs.persian":"Persian","mejs.polish":"Polish","mejs.portuguese":"Portuguese","mejs.romanian":"Romanian","mejs.russian":"Russian","mejs.serbian":"Serbian","mejs.slovak":"Slovak","mejs.slovenian":"Slovenian","mejs.spanish":"Spanish","mejs.swahili":"Swahili","mejs.swedish":"Swedish","mejs.tagalog":"Tagalog","mejs.thai":"Thai","mejs.turkish":"Turkish","mejs.ukrainian":"Ukrainian","mejs.vietnamese":"Vietnamese","mejs.welsh":"Welsh","mejs.yiddish":"Yiddish"}}; /* ]]> */ </script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/mediaelement/mediaelement-and-player.min.js?ver=4.2.17" id="mediaelement-core-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/mediaelement/mediaelement-migrate.min.js?ver=6.7.2" id="mediaelement-migrate-js"></script> <script type="text/javascript" id="mediaelement-js-extra"> /* <![CDATA[ */ var _wpmejsSettings = {"pluginPath":"\/wp-includes\/js\/mediaelement\/","classPrefix":"mejs-","stretching":"responsive","audioShortcodeLibrary":"mediaelement","videoShortcodeLibrary":"mediaelement"}; /* ]]> */ </script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/mediaelement/wp-mediaelement.min.js?ver=6.7.2" id="wp-mediaelement-js"></script> <script type="text/javascript" src="https://www.engineersgarage.com/wp-includes/js/mediaelement/renderers/vimeo.min.js?ver=4.2.17" id="mediaelement-vimeo-js"></script> <script type="text/javascript">jQuery(document).ready(function($) { $(".ui-tabs").tabs(); });</script> <script>"undefined"!=typeof jQuery&&jQuery(document).ready(function(){"objectFit"in document.documentElement.style==!1&&(jQuery(".cat-post-item figure").removeClass("cat-post-crop"),jQuery(".cat-post-item figure").addClass("cat-post-crop-not-supported")),(document.documentMode||/Edge/.test(navigator.userAgent))&&(jQuery(".cat-post-item figure img").height("+=1"),window.setTimeout(function(){jQuery(".cat-post-item figure img").height("-=1")},0))});</script> <script type="text/javascript"> if (typeof jQuery !== 'undefined') { var cat_posts_namespace = window.cat_posts_namespace || {}; cat_posts_namespace.layout_wrap_text = cat_posts_namespace.layout_wrap_text || {}; cat_posts_namespace.layout_img_size = cat_posts_namespace.layout_img_size || {}; cat_posts_namespace.layout_wrap_text = { preWrap : function (widget) { jQuery(widget).find('.cat-post-item').each(function(){ var _that = jQuery(this); _that.find('p.cpwp-excerpt-text').addClass('cpwp-wrap-text'); _that.find('p.cpwp-excerpt-text').closest('div').wrap('<div class="cpwp-wrap-text-stage"></div>'); }); return; }, add : function(_this){ var _that = jQuery(_this); if (_that.find('p.cpwp-excerpt-text').height() < _that.find('.cat-post-thumbnail').height()) { _that.find('p.cpwp-excerpt-text').closest('.cpwp-wrap-text-stage').removeClass( "cpwp-wrap-text" ); _that.find('p.cpwp-excerpt-text').addClass( "cpwp-wrap-text" ); }else{ _that.find('p.cpwp-excerpt-text').removeClass( "cpwp-wrap-text" ); _that.find('p.cpwp-excerpt-text').closest('.cpwp-wrap-text-stage').addClass( "cpwp-wrap-text" ); } return; }, handleLazyLoading : function(_this) { var width = jQuery(_this).find('img').width(); if( 0 !== width ){ cat_posts_namespace.layout_wrap_text.add(_this); } else { jQuery(_this).find('img').one("load", function(){ cat_posts_namespace.layout_wrap_text.add(_this); }); } return; }, setClass : function (widget) { // var _widget = jQuery(widget); jQuery(widget).find('.cat-post-item').each(function(){ cat_posts_namespace.layout_wrap_text.handleLazyLoading(this); }); return; } } cat_posts_namespace.layout_img_size = { replace : function(_this){ var _that = jQuery(_this), resp_w = _that.width(), resp_h = _that.height(), orig_w = _that.data('cat-posts-width'), orig_h = _that.data('cat-posts-height'); if( resp_w < orig_w ){ _that.height( resp_w * orig_h / orig_w ); } else { _that.height( '' ); } return; }, handleLazyLoading : function(_this) { var width = jQuery(_this).width(); if( 0 !== width ){ cat_posts_namespace.layout_img_size.replace(_this); } else { jQuery(_this).one("load", function(){ cat_posts_namespace.layout_img_size.replace(_this); }); } return; }, setHeight : function (widget) { jQuery(widget).find('.cat-post-item img').each(function(){ cat_posts_namespace.layout_img_size.handleLazyLoading(this); }); return; } } let widget = jQuery('#category-posts-2-internal'); jQuery( document ).ready(function () { cat_posts_namespace.layout_wrap_text.setClass(widget); cat_posts_namespace.layout_img_size.setHeight(widget); }); jQuery(window).on('load resize', function() { cat_posts_namespace.layout_wrap_text.setClass(widget); cat_posts_namespace.layout_img_size.setHeight(widget); }); // low-end mobile cat_posts_namespace.layout_wrap_text.preWrap(widget); cat_posts_namespace.layout_wrap_text.setClass(widget); cat_posts_namespace.layout_img_size.setHeight(widget); } </script> </body></html>