“A cheap beam break sensor utilising a reflector panel instead of a transmitter / receiver setup. Capable of handling long distances.
Specific parts list:
I found These LEDs with a half-angle of 5 degrees able to emit 100mA of power. They also emit light at 940nm which is perfect for the receiver.
Vishay TSSP4038 IR receiver. The receiver is made to detect continuous 38kHz light also. Some other sensors need bursts which I weren’t ready to figure out how to code.
Arduino Pro Mini 3.3v
D-SUN adjustable voltage regulator. I just had it lying around
5V Relay module able to be triggered by the 3.3V Arduino
0.1uF Capacitor
300uF capacitor
2N7000 transistor (This one can only handle 200mA so that limits the power for the LEDs but it’s still more than the 20mA the Arduino pin can output) Might want to upgrade to a 2N2222 instead if more power is needed.
I’ve gathered bits and pieces from other projects to make this. The coding could probably be nicer looking and so could the soldering. But hey, it works.
I wanted to make a sensor with no dedicated transmitter but a reflector panel instead. Also, it needed to be long-range. It’s fairly easy to find these on ebay but pretty damn difficult to find any with a range of about 15m which I need. So I built one…
I had a lot of trouble getting this thing working but two things I learned were that the capacitor near the sensor is a MUST and that light pollution is a bitch. I ended up covering the whole sensor in Sugru (except the front, obviously) to keep stray light out. It’s pretty difficult to see that annoying IR light but I realised that it travelled through the plastic PCB-ish material. The Sugru did it.”