The Sensor Watch

The Sensor Watch is a board replacement for the classic Casio F‑91W wristwatch. It is powered by a Microchip SAM L22 microcontroller with built-in segment LCD controller. You can write your own programs for the watch using the provided watch library, program the watch over USB using the built-in UF2 bootloader, and then install the board in your existing watch case to run your own software on your wrist.

Photo: a close-up of the Sensor Watch circuit board, and a wristwatch displaying the word “Hello”

Features:

ARM Cortex M0+ microcontroller
32KHz crystal for real-time clock with alarm function
Ten digit segment LCD, plus five indicator segments
Three interrupt capable buttons
Red / green PWM’able LED backlight
Optional piezo buzzer (requires some light soldering)
On-board USB Micro B connector
Reset button with double-tap UF2 bootloader
Nine-pin flex PCB connector