PIC 12F675 battery monitor using a diode/LED and resistor

Here’s a circuit by Joe Desbonnet’s Random Tech Stuff that’s designed to monitor battery voltage. It uses one resistor, one diode (or LED), one microcontroller ADC input and one digital output. A practical application using a PIC 12F675 is presented. This allows you to monitor battery voltage under load, allowing sufficient time to replace the […]