I am having a problem that the state of the LED's is not changing. I did the usual of blocking the beam path and there was no change. I do not know if the problem is something stupid; however, I have looked the project over carefully, or if the sensor is bad.
How should I test the sensor?
I am looking for something like, with a 5V input, the voltage at pin X should be X volts when the sensor is working properly.