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.

This circuit uses invisible ... people are moving. Two Infrared LEDs always emit continuous infrared beam to the Photodiode. The IR LEDs and Photodiode are placed on the opposite frames of the door ...

Messing around with Arduino can lead to some ... controlling the current in an electrical circuit. This is particularly important if your project uses LEDs, or is complex enough to otherwise ...

[Hulk] has your back with this simple but effective IR Remote Tester / Decoder. How to connect the TSOP4838 to an Arduino to ... easily drive a visible LED with just a resistor for a current ...

[Computergeek] made an Arduino Shield in order to use ... he should probably have invited a resistor to the party the two IR LEDs are having.

Typically, reflective-type infrared ... circuit works off a 9-V dc supply and can be powered by a compact PP3/6F22-type battery. On power-up, current flows through resistor R1, and the LED inside ...