PWR - Power Supply Duties Provide +5v power to the computer Provide charging current for the Ni-Cd battery LED outputs for Power on, Battery Present, Charging, Charge complete Parts LM2576 (TI?, 3A?) lm2576hv.pdf ATTiny84 Ni-Cd Monitor ATtiny24A-44A-84A-DataSheet-DS40002269A.pdf Based on Freescale MC68HC908QY4A Example AN2679.pdf AN3392.pdf