--- title: Cheap Smart Ring Becomes MIDI Controller | daily.dev description: A $20 Colmi R02 smart ring was converted into a MIDI controller by reprogramming its firmware. The device lacks code signing or encryption, making it easy to... canonical: https://daily.dev/posts/cheap-smart-ring-becomes-midi-controller-c8vb6o06h twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Cheap Smart Ring Becomes MIDI Controller | daily.dev og:description: A $20 Colmi R02 smart ring was converted into a MIDI controller by reprogramming its firmware. The device lacks code signing or encryption, making it easy to... og:url: https://daily.dev/posts/cheap-smart-ring-becomes-midi-controller-c8vb6o06h og:image: https://api.daily.dev/og/posts/c8vb6O06H.png og:image:alt: Cheap Smart Ring Becomes MIDI Controller 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. # Cheap Smart Ring Becomes MIDI Controller **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 1 upvotes · 0 comments ## Summary A $20 Colmi R02 smart ring was converted into a MIDI controller by reprogramming its firmware. The device lacks code signing or encryption, making it easy to upload custom firmware. The ring's accelerometer data is transmitted via Bluetooth to a web app that converts it into MIDI CC commands, enabling control of synthesizer parameters like filter cutoff frequencies. The project demonstrates how affordable consumer hardware can be repurposed for musical expression without requiring custom hardware builds. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Wearable MIDI Controller Built With Raspberry Pi](https://daily.dev/posts/wearable-midi-controller-built-with-raspberry-pi-w7fzp4ndh) · Hackaday · 0 upvotes · 0 comments - [Pebble’s founder introduces a $75 AI smart ring for recording brief notes with a press of a button](https://daily.dev/posts/pebble-s-founder-introduces-a-75-ai-smart-ring-for-recording-brief-notes-with-a-press-of-a-button-z2tsekeme) · TechCrunch · 0 upvotes · 0 comments - [Wireless MIDI Controller Has Lots Of Knobs](https://daily.dev/posts/wireless-midi-controller-has-lots-of-knobs-2agd1o16r) · Hackaday · 0 upvotes · 0 comments --- Tags: [#bluetooth](https://daily.dev/tags/bluetooth), [#embedded](https://daily.dev/tags/embedded), [#hardware](https://daily.dev/tags/hardware), [#iot](https://daily.dev/tags/iot) [View this post on daily.dev](https://daily.dev/posts/cheap-smart-ring-becomes-midi-controller-c8vb6o06h) ```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":"Cheap Smart Ring Becomes MIDI Controller","url":"https://daily.dev/posts/cheap-smart-ring-becomes-midi-controller-c8vb6o06h","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/cheap-smart-ring-becomes-midi-controller-c8vb6o06h"},"datePublished":"2026-01-31T18:16:14.933Z","dateModified":"2026-03-15T05:54:43.289Z","description":"A $20 Colmi R02 smart ring was converted into a MIDI controller by reprogramming its firmware. 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