Projects › Projects › capacitive liquid level measurement using LM324 › Are you using a filter
April 18, 2012 at 1:46 pm #7483
Are you using a filter capacitor for the full wave rectifier? try without it?
Also try this, just use a diode as the rectifier, amplify the half waves using lm324, connect the output to ADC of the controller and in your code check for only the maximum voltage occuring.