I bought your QRE1113 Digital board. Hooked up 5V and ground, but I don’t get any output. I expected to see a voltage change. Perhaps my unit is defective. I would love a typical schematic to drive an LED. I see 220 ohm resistor, and can add more between the output pin and LED. Not even sure whether the output goes high or low with the beam blocked or clear. My goal is to use my finger to block it, hence creating an electronic input switch (instead of a mechanical pushbutton) to a raspberry pi, but, I’m wired for 5 V. Thanks all you smart folks
Hi Ron,
How are you measuring the output? Do you possibly have a microcontroller you can hook it up to and watch the Output pin’s activity with a digitalRead? That would be the best way to test it but you should be able to watch it with a multimeter probing the OUT pin.
Hi Ron.
A quick and easy way to test these would be to put a LED between VCC and OUT. When nothing reflective is nearby the sensor the LED will be off. When you bring a reflective object near the sensor the LED will light up. The closer the object, the brighter the LED will glow.
If you’re looking for a voltage output, connect a 10K resistor between VCC and OUT and then measure voltage between OUT and GND. You will see 5 volts when nothing reflective is in front of the sensor and the voltage will drop to near 0 when a reflective object is in front.
Thanks so much for such a quick reply. I’ll try both tomorrow, when I get more sensors to try.