Frienda20 Pieces IR Infrared Obstacle Avoidance Sensor Module 3-Wire Reflective Photoelectric Sensor Module Compatible with Arduino/Raspberry Pi 3/Smart Car Robot

Nice, tiny, and functional circuit boards. Very easy to test, and subsequently build into a N scale model train system. I am using several of them to control station and crossing lights. I added another timing circuit to maintain the lights ON for a few seconds after the trains pass and the OPTO turns OFF.I have found though that the advertised distance of 30cm is not accurate. I bench tested them and found that they actually only detected obstacles to about 4.5 - 5 inches (around 12cm), which is well short of the advertised 30cm (11.8 inches). Not a problem for my setup however. I did test 4 of the 20 units and found very little variation in their functioning.The batch of 20 is a lifetime supply for me, so no need to order more. But I do recommend them within their operating range and the caveats noted.

I used these IR detectors differently than the intended method and some of them failed. Not sure if it was my fault but these are pretty inexpensive products so maybe that was the problem.

I bought these for a robotics class for my students. We ended up using a slightly different version of these sensors that have the IR emitter and receiver in a common plastic housing (and has analog output). These are a good value for the money but require a little work to get the most out of them. The emitter and receiver are discrete so their alignment relative to one-another can make a difference in the response and performance. So mount the unit then carefully bend the leads on the emitter and receiver to where you want them to point. In our case we were doing black line detection and these worked best at a slight angle from vertical. So move them around to see what works best for your use case. Adding a light barrier between the emitter and receiver won't hurt. Neither would encasing both in a small tube to keep out stray IR sources. Finally the pot should be tweaked to match the use case - distance, reflectivity of the target, etc. The built-in status LED is wonderful - it allows tuning with only power applied (no software needed). The digital output is active low (green LED on). Beware of electrostatic discharge (ESD) - we blew a few LM393 comparator (the small black chip) and IR receivers from static. Overall these are cheap and effective; good for simple projects.

I used these to sense an HO train going over them, and they work better than the photo sensor type. They turn on and off the crossing for my layout.I need 8 because there are two roads to cross, and plan on putting in lights for block detection, which means using them for that as well.I don't think I'll buy more, unless I go through the 20 I have, and that might happen with more ideas coming.

This detector works, but nowhere near a max distance of 30cm ~ 12in. I got max distances of around 6.5cm ~ 2.6in. I was using a 5V source. The description says the deflection angle is 35 degrees. In actuality, it's nowhere near that. It might be half that, probably less. The manufacturer must know it has hyped the performance parameters on this product. Amazon ought to require the manufacturer to give customers the correct values.The modules come with the screw distance adjustment set to near minimum distance of around 0.5in. To get longer distances, rotate the screw adjustment clock wise. You will find out that before the screw reaches its end rotation, the module will turn on and stay there at what looks like a detection distance of 0.0in...useless. At its max detection range, the screw adjustment is sensitive to very small rotations. The max distance of 2.6in works well for me, but Im sure many applications would require a greater detection distance.

Works great.This is not an analog input device, on the Arduino. It only puts out 0 (0VDC) and 1 (5VDC), binary outputs. So, be sure to connect it to Digital IO Input Pins, or know that if you connect it to Analog inputs, you're basically only going to see 0 and 1024 on your Analog Input pins.

Fine

Arrived in good condition and works well