@robert-hh said in ADC sensors on external PSU: @Alephus Connecting the sensor to the input should not raise the voltage measure at that connection. So it must be something else in the set-up. after a while i did a few more tests and found something: of all ADC1 pins, all behave properly except P19 and P20 (guess wich 2 i was using) a friend analized my problem as well and detected that those 2 pins where not "floating", and after analazing the datasheet he assumes its because they are the only ones with pullup/pulldown internal resistors. So for now i have a solution however i still dont understand is why, after all, they are tecnicaly valid Pins pins in the datasheet

@jcaron as of right now what I want to achieve: Using a SCD30 sensor (which gets humidity, temperature and CO2 levels) read the data and save it, for that I intend to create (or modify based on other libraries) the library for the sensor. I already have the adress of the sensor and the hexadecimal "commands" and I am trying to use the libraries of the Pysense sensors as a template