I'm using the analog inputs on the Arduino Uno R3 to measure voltage values between 0-5V. I ran out of analog inputs. Is there a way to expand the amount of analog inputs? Can the digital pins be used as analog input pins?
Sorta un-related side question: Whenever I have the Arduino Motor shield on top of the Arduino board, I notice that the A1 + A0 inputs no longer are able to sense any voltage values and the A2+A3 inputs are always measuring 5V, even when open. Is the motor shield broken? Is this abnormal behavior? Therefore, Im looking for other ways to increase the analog input sensors.