Move Ultralight is an open-source wearable health tracker without a display. It continuously tracks heart rate, blood oxygen (SpO2), heart rate variability, sleep, stress, respiratory rate, skin temperature, and daily activity—for 10+ days on a single charge—and communicates through a companion app, haptic feedback, and LED indicators.

The Open Wearable for Health Insights

Move Ultralight’s screenless design is a deliberate choice: low-power and distraction-free, with every milliamp going into sensor accuracy and battery life. This adds up to a small, light wearable that can last more than a week on a single charge. A 20-pin expansion FPC connector lets strap-integrated modules extend sensing or add new functionality. No subscription, no paywall, no vendor lock-in — and you retain your right to repair.

All health intelligence runs on the device itself. Over 30 days it learns your personalized baselines to flag meaningful shifts—recovery that is truly good versus merely average, training that is building fitness versus fatigue, and subtle multi-signal drifts that may hint at illness. No health data leaves your wrist.

The companion app (Flutter, iOS and Android) is your critical visual interface. It shows a morning dashboard, sleep staging with hypnogram, personalized recovery, fitness/fatigue curves with daily TRIMP, and anomaly alerts when multiple biomarkers drift together. Every screen drills down to the underlying raw data — including a dedicated view for raw PPG waveforms at full sample rate, the same signals the on-device algorithms see. Everything stays on your phone, with CSV/JSON export and BLE streaming for your own analysis in Python or custom models.

What it won’t change: your motivation, sleep hygiene, or training discipline. This is a tool, not a coach.

Features & Specifications

• Optical array: 2× green + 2× red + 2× IR LEDs + 4× photodiodes, driven by the AS7058 AFE (120 dB SNR, NDA-free)
• Processing: STM32U595 + nRF54L15, both on Zephyr RTOS, 6-axis IMU, skin temperature (±0.1°C)
• Battery: 300 mAh Li-Po, 10+ days typical
• Interaction & I/O: Haptic feedback, LED indicators, USB Type-C (direct) and magnetic pogo dock charging
• Expansion: 20-pin FPC connector, BLE 5.4 with raw PPG streaming and dual-SoC OTA
• Dimensions: 36 × 20 × 11 mm (1.4 x 0.78 x 0.43 in)
• Weight: < 20 g (~0.7 oz)

Open Source

Move Ultralight is fully open-source. The NDA-free AS7058 PPG AFE lets us publish the entire stack with no black boxes: firmware for both SoCs, drivers, register configurations, and signal processing pipelines (Apache 2.0); KiCad schematics, PCB layout, Gerbers, and BOM (CERN-OHL-P v2); ML models and training scripts (Apache 2.0); Flutter companion app source (Apache 2.0); and enclosure CAD (CERN-OHL-P v2). Everything will be published on GitHub as it is ready.

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