--- title: ESP32 Rotary Display Makes Ideal Timer | daily.dev description: [mircemk] built a 'Universal Timer' using a CrowPanel Rotary Display, which pairs an ESP32-S3 with a 480x480 round touchscreen and a built-in rotary encoder.... canonical: https://daily.dev/posts/esp32-rotary-display-makes-ideal-timer-9jssqtdt9 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: ESP32 Rotary Display Makes Ideal Timer | daily.dev og:description: [mircemk] built a 'Universal Timer' using a CrowPanel Rotary Display, which pairs an ESP32-S3 with a 480x480 round touchscreen and a built-in rotary encoder.... og:url: https://daily.dev/posts/esp32-rotary-display-makes-ideal-timer-9jssqtdt9 og:image: https://api.daily.dev/og/posts/9JSSqtdt9.png og:image:alt: ESP32 Rotary Display Makes Ideal Timer og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # ESP32 Rotary Display Makes Ideal Timer **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 1 upvotes · 0 comments ## Summary [mircemk] built a 'Universal Timer' using a CrowPanel Rotary Display, which pairs an ESP32-S3 with a 480x480 round touchscreen and a built-in rotary encoder. Twisting the encoder ring sets the countdown time, and the circular graphics rotate to match. A PCF8574 I2C I/O expander drives a buzzer for audio feedback when the timer ends. The display also changes color as it nears zero, making remaining time easy to read from across a room. The project's code is freely available to flash and modify. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What hardware does the CrowPanel Rotary Display use for a rotary encoder timer project? The CrowPanel Rotary Display is a 2.1 inch module combining an ESP32-S3 with a 480x480 round touchscreen and a built-in rotary encoder ring. In the 'Universal Timer' project by mircemk, it's paired with a PCF8574 I2C I/O expander to drive a buzzer that sounds when the countdown reaches zero. _Browsing ESP32 display projects like this one is easier with daily.dev's dev-focused feed._ ### How can I give visual feedback for a countdown timer on a round display? One approach, used in an ESP32-S3 rotary timer project, is to rotate the circular graphics on the screen as a user twists a physical encoder ring to set time, then shift the display's color as the countdown nears zero. This makes remaining time readable at a glance from across a room, without needing to read numbers closely. _Makers refining UI feedback ideas for embedded displays often track similar builds on daily.dev._ ## Similar posts on daily.dev - [Rotary encoder with 1.8-inch touch display gets upgrade to ESP32-S31 SoC](https://daily.dev/posts/rotary-encoder-with-1-8-inch-touch-display-gets-upgrade-to-esp32-s31-soc-i8boluiv6) · CNX Software · 1 upvotes · 0 comments - [Elecrow CrowPanel Rotary Display Review: A Smart Knob for DIY Enthusiasts](https://daily.dev/posts/elecrow-crowpanel-rotary-display-review-a-smart-knob-for-diy-enthusiasts-euicjrjhz) · It's Foss · 0 upvotes · 0 comments - [You, too, can make this sleek digital Pomodoro timer that runs off an ESP32](https://daily.dev/posts/you-too-can-make-this-sleek-digital-pomodoro-timer-that-runs-off-an-esp32-kyed75cbi) · XDA Developers · 2 upvotes · 0 comments - [A Simple Desktop Pomodoro Timer](https://daily.dev/posts/a-simple-desktop-pomodoro-timer-h1cv4cuu2) · Hackaday · 0 upvotes · 0 comments - [This ESP32 project couples a simple clock with some iconic retro gaming references](https://daily.dev/posts/this-esp32-project-couples-a-simple-clock-with-some-iconic-retro-gaming-references-2b1omg9og) · XDA Developers · 2 upvotes · 0 comments --- Tags: [#hardware](https://daily.dev/tags/hardware), [#iot](https://daily.dev/tags/iot), [#embedded](https://daily.dev/tags/embedded) [View this post on daily.dev](https://daily.dev/posts/esp32-rotary-display-makes-ideal-timer-9jssqtdt9) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"ESP32 Rotary Display Makes Ideal Timer","url":"https://daily.dev/posts/esp32-rotary-display-makes-ideal-timer-9jssqtdt9","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/esp32-rotary-display-makes-ideal-timer-9jssqtdt9"},"datePublished":"2026-10-27T08:26:11.090Z","dateModified":"2026-10-27T08:26:35.005Z","description":"[mircemk] built a 'Universal Timer' using a CrowPanel Rotary Display, which pairs an ESP32-S3 with a 480x480 round touchscreen and a built-in rotary encoder....","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ca66904d6568a4d1b007aca0c2012be?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ca66904d6568a4d1b007aca0c2012be?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hackaday","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hackaday","logo":"https://media.daily.dev/image/upload/s--JhDfhy70--/f_auto,q_auto/v1767541814/logos/hackaday","url":"https://daily.dev/sources/hackaday"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/esp32-rotary-display-makes-ideal-timer-9jssqtdt9","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"hardware,iot,embedded","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hackaday","item":"https://daily.dev/sources/hackaday"},{"@type":"ListItem","position":3,"name":"ESP32 Rotary Display Makes Ideal Timer"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/esp32-rotary-display-makes-ideal-timer-9jssqtdt9#faq","mainEntity":[{"@type":"Question","name":"What hardware does the CrowPanel Rotary Display use for a rotary encoder timer project?","acceptedAnswer":{"@type":"Answer","text":"The CrowPanel Rotary Display is a 2.1 inch module combining an ESP32-S3 with a 480x480 round touchscreen and a built-in rotary encoder ring. 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