Here is the diagram of my Arduino infrared close proximity sensor. As you can see, the core part of my experimental setup is an Arduino UNO, but other compatible microcontrollers can also be employed.

Because of the affordability and seeming ubiquity of the Arduino ... the part can be a fairly expensive proposition. Thankfully, [Libelium] has already tested and verified a number of tubes ...

The part list consists of one Arduino, two resistors, and one IR emitter. That’s right, an emitter. When an LED (IR or otherwise) is reverse biased it can act as a light sensor. The main ...