I’m getting ready to put together a small control panel with some buttons in a simple resistor ladder, and use the voltage reading across the circuit with each closed button via analogRead. However, as I’m working to design the pieces, I’m reading some information about the proper way to calibrate the readings from analogRead depending on whether the Arduino is powered by USB or external power supply.
What I think I’m reading is that calibrating the readings from the analogRead function while powered by USB is a bad idea because USB power can vary - but I thought the 5V pin on the Arduino was regulated regardless of source. Should I power my button pads from a separate/dedicated source?
I am doing this from scratch so I’d like to do it as “right” as possible from the start - I may be wiring up between four to six buttons on a few separate PCB strips.