ProtoCentral's Move Ultralight Is a Screen-Free, Distractionless, Open Source Smart Fitness Wearable
No screen, no problem: this permissively-licensed wearable runs small machine learning models on-device to track your health changes.
Begaluru-based ProtoCentral Electronics is preparing to launch an open-hardware screen-free health tracker designed to adorn your wrist and provide detailed fitness and health data without the distraction — powered by an STMicroelectronics STM32U595 microcontroller and Nordic Semiconductor nRF54L15 communications coprocessor: the Move Ultralight.
"Move Ultralight’s screenless design is a deliberate choice: low-power and distraction-free, with every milliamp going into sensor accuracy and battery life," the company explains of its design ethos. "This adds up to a small, light wearable that can last more than a week on a single charge. A 20-pin expansion FPC [Flexible Printed Circuit] 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."
The compact wearable isn't a smartwatch — there's no display, though the gadget does include a small motor for basic haptic feedback. Instead, it's designed to communicate with a companion app running on your smartphone and provide ongoing readings for heart rate and blood oxygen concentration, which are then used to calculate heart-rate variability, stress levels, breathing rate, and more.
"All health intelligence runs on the device itself," ProtoCentral promises, putting privacy at the forefront of the watch's software design. "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," the company adds. "It shows a morning dashboard, sleep staging with hypnogram, personalized recovery, fitness/fatigue curves with daily TRIMP [Training Impulse], and anomaly alerts when multiple biomarkers drift together. Every screen drills down to the underlying raw data — including a dedicated view for raw PPG [photoplethysmogram sensor] waveforms at full sample rate, the same signals the on-device algorithms see. Everything stays on your phone, with CSV/JSON export and BLE [Bluetooth Low Energy] streaming for your own analysis in Python or custom models."
The custom board is built around a pair of microcontrollers, the STMicroelectronics STM32U595 as the primary controller and the Nordic Semiconductor nRF54L15 as a communications coprocessor, both running the Zephyr real-time operating system (RTOS). There's a six-axis inertial measurement unit (IMU), a skin temperature sensor, and a multi-spectral green/red/infrared photoplethysmogram sensor. "The NDA [Non-Disclosure Agreement]-free [ams OSRAM] AS7058 PPG AFE [Analog Front-End] lets us publish the entire stack with no black boxes," the company says of this latter component.
The company has pledged to release full firmware, drivers, register configurations, and signal processing pipelines for the wearable under the permissive Apache 2.0 license, with hardware design files including KiCad project files and production Gerbers plus CAD files for the enclosure to be released under the permissive variant of the CERN Open Hardware License 2; the machine learning models and training scripts for the on-device health monitoring will be made available under the Apache 2.0 license too, along with the source code for the mobile companion app.
ProtoCentral is preparing to launch a crowdfunding campaign for the Move Ultralight, with interested parties invited to sign up on Crowd Supply to be notified when it goes live.