I'm also having issues getting the signal to show up through the Gecko G540.
I'm using a reflective opti-switch.
I'm using a 5V PS with a 150 Ohm resistor to power the IR LED (1.6V Forward, hence the 150R to keep from annihilating the LED). I can see the IR is working by looking at it through a digital camera lens.
If I connect the multimeter to the collector and emitter wires and rotate the spindle by hand I detect changes in resistance when the spindle is at the reflective part. (I have black electricians tape wrapped around the spindle with a portion cutout.) I have the sensor sitting 0.005" from the edge of the spindle. Used a feeler gauge and push the sensor up to it, tightened down the screws, removed the feeler gauge.
I put the wire which I determined to be positive (collector?) in Pin #3 inlet on the 12-Terminal strip and the other wire (emitter?) in the #12 inlet. I then set the Ports & Pins to Index > Port 1, Pin 12. However, I'm not see anything on the Index LED from the Diagnostics page when I rotate the spindle. I've changed to Active Low, but still nothing is detected.
The debounce was set to 0, so I tried 2, 10, 50, still nothing.
Am I supposed to use some sort of Pull-Up or Pull-Down resistor at Pin #3? if so, what resistance?