BMS - cell at a time
This is an attempt at a single cell daisy chain Battery Management System. Emphasis is placed on minimum power draw and cost. Hopefully it is also reliable.
Most parts are over specified, however I worry that having the microcontroller powered directly from the cell could lead to bad things if the cell ever has a voltage spike on it. The type caused by a loose connection maybe especially bad.
Be warned.
This uses a newer generation of ATtiny that is commonly used with Arduino. Current firmware uses Microchip Studio, and I have used a ATtiny416xplained demo board to flash the ATtiny202 Alternatively, firmware could be developed that uses Arduino IDE, with a programmer made as described here: https://github.com/SpenceKonde/AVR-Guidance/blob/master/UPDI/jtag2updi.md
v1.1
- incorporate uC pin swap mod
- improve connections
v1.0 Initial test production run. Mostly works. If you ever get one of these boards, check to see the modification is done to swap FAULT and EN pins.
Application: KiCad Version: (5.1.10-1-10_14), release build