Testing the Reference Detector

The reference detector measures the LED brightness, along with the ambient light level. This provides a voltage that will be subtracted from the signal detector, so we can tell if there is an object under the coil.

To review the reference detector circuit go here.

The reference detector circuit is electrically identical to the signal detector. The only difference is the physical placement of the sensor.

See if it's Working

Please repeat the check-out procedure you used when testing the signal detector.

If I think of anything new or special or different, I'll add it! So far I can't come up with any differences.