Oddly Specific Objects Sensor Watches Lite & Pro

Oddly Specific Objects Sensor Watches Lite and Pro utilize the capabilities of an ultra-low-power Arm® Cortex® M0+ microcontroller upgrade for Casio F-91W or A158W watches. These sensor watches include a small circuit, less than an inch in diameter, and feature a 100mAh single-coin cell battery. The sensor watches Pro and Lite use a monochrome segment LCD on the Casio F-91W and A158W for an always-on display that consumes less power. The sensor watch Pro features an RGB LED, an infrared light sensor, a voltage boost for the piezo buzzer for extra volume, and a soldering-free installation experience. Additional features of Sensor Lite include clock, moon phase, backpacker, stargazer, athlete, sunrise/sunset, and world clock. Additional features of Sensor Pro include day/night percentage, menstrual cycle, interval timer, tarot, wordle, couch to 5K, TOTP, countdown, advanced alarm, and simple calculator.

Features

  • Raw segment LCD glass/monochrome segment LCD to provide an always-on display that consumes mere microamperes of power
  • Can run for over a year on a single 100mAh coin cell, eliminating the need for frequent recharging
  • Reusable water-resistant F-91W and A158W enclosures
  • Sensor watch pro:
    • Louder buzzer (with no soldering)
    • Sports a red, green, and blue LED, which can backlight your watch in all the colors of the rainbow
    • Day/night percentage
    • Interval timer
    • Menstrual cycle
    • Couch to 5K
    • Time-based One-Time Passwords (TOTP) watch face
    • Wordle
    • Tarot
    • Countdown
    • Advanced alarm
    • Simple calculator
  • Sensor watch lite:
    • Clock
    • Wrld clock
    • Sunrise/sunset
    • Moon phase
    • Timer
    • Backpacker
    • Stargazer
    • Athlete

Specifications

  • Arm® Cortex® M0+ microcontroller running at up to 32MHz
  • 256KB of on-chip Flash, with up to 8KB EEPROM emulation area
  • 32KB of RAM with full retention in low-power standby mode
  • 32.768kHz crystal for real-time clock functionality with alarm support
  • Red and green PWM-able LED backlight
  • Temperature sensor
  • On-board USB Micro B connector
  • Reset button with double-tap UF2 bootloader
  • Edge-plated contacts for three interrupt-capable buttons
  • Open source
  • Sensor watch lite:
    • Controller for ten-digit segment LCD, plus five indicator segments
    • Connection pad for piezo buzzer (requires light soldering)
  • Sensor watch pro:
    • Infrared phototransistor for light sensing
    • Controller for classic Casio segment LCD or custom Sensor Watch LCD
Oddly Specific Objects Sensor Watches Lite & Pro

Videos

Published: 2026-03-10 | Updated: 2026-03-13