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Sensor Watch board shown with a digital watch.

Electronics ยท Ships from IL

Sensor Watch

ARM Cortex-M0+ board upgrade that turns a Casio F-91W/A158W into a hackable watch.

$39.00 US only
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Sold by HackBazaar Demo Bench

Details

Sensor Watch is a drop-in electronics upgrade for classic Casio F-91W and A158W watches. It replaces the original quartz movement with a Microchip SAM L22 ARM Cortex-M0+ board while keeping the familiar case, buttons, and low-power segmented LCD.

The board runs the open-source Movement firmware and can display world time, sunrise and sunset, moon phase, long timers, and custom watch faces. A USB Micro-B connector and UF2 bootloader make firmware updates feel like copying a file, while the onboard temperature sensor, RTC, ADC, PWM-capable pads, UART-capable pads, and red/green backlight leave room for practical hacks.

Good fit for: wearable firmware experiments, low-power timekeeping, TOTP-style utilities, field logging, and anyone who wants a classic digital watch that can still be reprogrammed.

Battery

Seller Notes

Requires installation into a compatible donor watch. Coin cell battery and small parts present. Optional buzzer support requires light soldering; water resistance depends on careful case reassembly.