8 Replies Latest reply on Jun 30, 2014 2:39 AM by SpiderKenny

    Galileo Analog Input Impedance

    joaocandre

      I'm using the analog inputs on Intel Galileo to measure voltage on a simple breadboard circuit. Using a voltage divider with two 10K resistors, I should measure halfscale on the middle node (between both resistors), and that's waht I see with the multimer. However, if I connect any of the analog pins between the resistors, the voltage stops being equally divided between the resistors, and instead I get 2.3V. On top of it, the value measured with analogRead() is ~348, which is not even equivalent to 2.3V.

       

      So there is current going into the analog pin, shouldn't an "input" pin have high impedance? How do I correct this behaviour?