The Sensor Watch circuit board is designed to fit in a Casio F-91W or A158 wristwatch. Note that it will not work with counterfeits! You need a genuine Casio F-91W wristwatch to serve as the donor watch for this board swap.
At a minimum, you will need a small Phillips screwdriver to perform this board swap. Tweezers can also help. Optionally, you may use a soldering iron to remove a small metal tab from the original F-91W circuit board, and solder it to the Sensor Watch board. This modification is necessary to get the buzzer to beep. Note that if you don’t do this swap, Sensor Watch will still work the same, with the exception that the buzzer will not sound.
You can view a video of the full board swap procedure here:
bit.ly/BoardSwap
or
youtu.be/Zr0pKeC2VFU
NOTE: The video shows all these steps in much greater detail; please watch it!
- Place the F-91W on a table with the display facing down.
- Remove the four screws on the back, then remove the backplate.
- Carefully remove the black gasket, taking care to note its orientation.
- Remove the watch movement.
- Unclip the metal retainer from the white plastic enclosure; set it aside.
- Remove the shiny battery contact from the green circuit board, and place it on the same spot on the Sensor Watch board.
- Remove the battery and the original F-91W circuit board.
- Place the Sensor Watch circuit board in the white plastic enclosure.
- Place the battery, negative side down, on the battery contact.
- Clip the metal retainer back onto the assembly. The display should turn on.
- Reassemble the watch: place the movement in the case, replace the gasket, and screw in the backplate.
If you encounter any issues, please reach out in the Sensor Watch Discord: discord.gg/Rdd9ewREaJ
Sensor Watch enters sleep mode after 1 hour. You can tell because the seconds will look different. Press the “Alarm” button to wake.
You can download alternate firmware at www.sensorwatch.net, where you can also learn to write your own custom watch faces!