Open Source Modular Smartwatch Platform for Hackers

C5/10March 18, 2026
WhatA customizable smartwatch platform with swappable sensor modules, expandable storage, and wireless data sync — built on the Sensor Watch concept but with modern capabilities.
SignalCommenters are genuinely excited about the Sensor Watch project (open source PCB replacement for Casio F-91W) but are hitting hard walls around limited storage preventing complex watch faces, no practical way to transfer data on/off the device, and wanting more sensor options — these are real users with real unmet needs.
Why NowUltra-low-power ARM chips (like the SAM L22 in Sensor Watch) have gotten cheap enough for hobbyist hardware, and the maker community has matured to support open watch ecosystems.
MarketHardware hackers and quantified-self enthusiasts; niche but passionate ($50-150 price point); Sensor Watch and PineTime are closest but both have significant limitations.
MoatAn ecosystem of community-built watch faces and sensor modules creates switching costs — once users invest in building for the platform, they stay.
More than 135 open hardware devices flashable with your own firmware View discussion ↗ · Article ↗ · 321 pts · March 18, 2026

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