Measuring netfrequency

From NURDspace
  • arduino, on pin 3 a 1kHz clock signal
  • the signal to measure is connected to pin A0 of the arduino


first attempt

  • when an interrupt comes in via pin 3, a uS timestamp is taken ('t0')
  • everytime the sign of the signal changes (via A0), then a timestamp is taken and the timestamp t0 is subtracted
  • also pin 8 is inverted (output pin)

result

  • it works somewhat but there's an enormous lapse

50hztest001.png

  • yellow is incoming 50Hz signal
  • blue is the toggle-pin (pin 8)