Measure Battery capacity with a microcontroller

Photo by Harrison Broadbent on Unsplash

I figured out that my self-designed home devices will empty, without any sign. So I decided to create a voltage meter into my code.

Hardware construct

For clarification, I will use an ESP device, this can only measure the largest input of 3,3V. But my Batteries have more consumption. For this, I must create first a voltage divider to get a…