Stripped down version of SIMPBMS Volt slave module code.
This varient removes all inputs and outputs except for key on input, SOC gauge level output, and charger enable output. Menus are removed and variables are configured under settings in the code. Currently set up to output SOC, Pack voltage, High cell v, Low cell v, cell delta, charger and balance state on Serial3 at 9600 baud. Only voltage based SOC currently supported for simplicity/minimal hardware.