Using ADC to Measure Voltage and Current

Example Circuit

+v via current regulator
  | 
  |----- analog2 in (LED anode)
 _|_
 \ /    <- LED
 _v__
  |
  ------- analog1 in  (LED cathode)
  |
 [ ]  
 [ ] <- current sensing resistor  (as close to 1 ohm as possible) 
 [ ]  
  |
  ------------ Ground



analog1 value will be proportional to current

analog2 will be the voltage on the led anode

(analog2 - analog1) value will be the voltage across the diode

See Also

Example using 2 potentiometers

Current-Sensing with Allegro ACS714 Hall-Effect-Sensor