2Pcs 3.3V-5V Tracking Sensor Module 8 Channel Finding Module Line Follower Infrared Detection Sensor 8 bit Detector Hunt Board PCB

Both worked upon arrive and after soldering the pins to the boards. Make sure to short the 3.3V solder bridge if you're not using 5V. The range of detection range is small, so ensure the 'obstacles' are close to the sensors so they reflect enough light from the LEDs. Seems to work with external IR sources as well, so it could be paired with a stronger source to increase the range a bit.

I was disappointed with these line follower sensor arrays. When I tested the individual sensors making up the arrays, I found 2 sensors in one of the arrays that did not work. Besides the issues with the product’s QC, the design of the sensor array has some questionable aspects. The pitch of the individual sensors is 5/16” or ~8mm, for sensors of this type the spacing is typically 3/8” or ~9.5mm. This reduction in spacing makes these sensors more susceptible to IR light crosstalk. These sensors arrays should be placed as close to the ground plane as possible (1mm) to minimize ambient light leakage. To use these sensor arrays you will need to construct a barrier between the individual sensors and a seal to prevent ambient light leakage. Using these sensor arrays without this extra shielding will be frustrating. Besides the crosstalk issues caused by the sensor to sensor spacing, the sensor is shorter, meaning its maximum detection range for finding a line is reduced. A quite common target line width is 3/4" (electrical tape width). This sensor is more suited for a 5/8” line.Only one of the sensors array fully worked and there are design dimension concerns. I would pass on these. There are better sensors available.

It does not work. Both of the sensors give 5v on D1-D8, regredless of anything else.