SITUATION: You've a potentiometer connected to an Arduino to provide a variable voltage to an analog pin. When turned toward one end or the other the potentiometer emits an evil-smelling smoke.

 

CAUSE: This is almost always a result of connecting the center pin of the potentiometer to ground (GND), Vin, or +5v, or +3.3v.

 

NEVER, NEVER, EVER connect the center pin of a potentiometer to a voltage or ground. For these lessons and labs the center pin is only ever connected to an Analog pin on an Arduino.

For our lessons the wiring of a potentiometer is:

  • One Outside Pin is connected to +5v
  • The Center Pin is connected to an analog pin on an Arduino.
  • The Other Outside Pin is connected to GND

 

NOTE: A potentiometer that has experienced these symptoms is almost certainly damaged to the point where it cannot be used. It should be discarded.