Just starting out, fiddling with an Uno. I would like to use the ADC with EXTERNAL reference voltage but I also would like to be able to swith back to 5V if needed (default).
Docs say, I need a 5K resistor if I want to do that. https://www.arduino.cc/en/Reference/AnalogReference&
The reference voltage I produce (1V) is coming from a voltage divider with resistors. Intuitively, I'd say I'm all set up but electronics tend to prove me wrong.
Q: Do I need another resistor before the pin and the output of the voltage divider?