first pcb design Contest
Appreciate Project

ATTINY85-based activity tracker, updated version (without the USB).

It uses a very low power LED driver and an accelometer so that the ATTINY (the part that consumes the most current) can safely sleep while the LEDs are on.


The previous version had USB that would necessitate using ATTINY85-20 or even an added crystal - and that wouldn't do for a low power badge because of higher voltage requirements and pins that the crystal would tie up.

I will keep looking for an MCU that can both provide USB, work off of <2.5V (as the battery discharges) and not be a challenge to program for normal people. As it is, the compromise here means that you need a programmer to program the ATTINY but those are readily available off-the-shelf parts.


I also added BOM this time so you know what to expect at least in the hardware department.

December 18,2017
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