BGTXINGI 10PCS TCRT5000 Infrared Reflective IR Photoelectric Sensor Switch Module 3.3-5V Obstacle Avoidance Barrier Line Track Sensor Module

Great sensors - I have 30 on my model railway. They work just fine and are very economical. Note, however, that at the time of purchase, the digital output on the sensors was 'low' when the IR detector senses an obstruction (IR light is reflected off the surface) and 'high' when there is no obstruction (no reflected IR light). As I wanted the reverse of this I had to build a simply inverter circuit (using cheap 'not' gates or similar) to invert the digital output. Some tech data - using a 4VDC supply, the digital output switches between 0.1VDC ('low') and 2.3VDC ('high') which is fine as the on/off threshold for my downstream circuitry is around 1.4VDC. I assume that using a 5VDC supply would result in the the 'high' digital output signal being closer to 3.3VDC. I don't use the analogue output so can't comment.

For me, I could do without the power and activity Leds which are surprisingly bright (at 5v) and both green and I'd rather they left out the pin header. I also wonder if only one of the 2 comparators in the LM393 is used, then maybe they could also use the other one to provide an active high detection output? The DO detection output is active low with a passive resistive pull up which was inconvenient for me as I needed to add an inverter to suit my application.Anyway, they do work and saves time making a mount for discreet IR sensors.