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ZSWatch — Open-Source Smartwatch with Zephyr Firmware
Fully open-source smartwatch with custom nRF5340 hardware and Zephyr RTOS firmware. Features 1.28-inch round touchscreen, BMI270 IMU, heart rate, magnetometer, microphone, and BLE companion apps for iOS and Android.
Boards:nRF5340
Firmware:Zephyr RTOS
Use Cases:wearablesFitness TrackingnotificationsOpen Hardware Development
ZSWatch
ZSWatch is a fully open-source smartwatch — both hardware design and firmware — built around the Nordic nRF5340 SoC running Zephyr RTOS. It's designed for makers and developers who want a complete, hackable smartwatch platform.
Hardware Specs
- SoC: Nordic nRF5340 (via u-blox NORA-B10) — dual-core 128 MHz, 512 KB RAM, 1 MB Flash
- Display: 1.28-inch round IPS TFT LCD, 240x240, capacitive touchscreen (30 MHz SPI)
- IMU: Bosch BMI270 — gesture detection, wrist-wake, step counting
- Pressure: Bosch BMP581 (~20 cm altitude accuracy)
- Magnetometer: ST LIS2MDLTR
- Ambient Light: Broadcom APDS-9306-065
- Microphone: Knowles SPK0641HT4H-1 (I2S)
- PMIC: Nordic nPM1300
- External Flash: Macronix 64 MB
- RTC: Micro Crystal RV-8263-C8
Software Features
- Multiple dynamic watch faces
- Pop-up notifications from phone via BLE
- Step counting and fitness tracking
- Compass, music control, settings apps
- iOS and Android companion apps
- Extensible application framework
Development
The WatchDK development kit ($99) provides the same SoC and sensors in a larger form factor with USB-C, breakout headers, and SWD/UART debug interface for easier development.
Partially funded by NGI0 Commons Fund. PCB manufacturing sponsored by PCBWay.