Testing an IR Sensor

Because there is a semiconductor/chip inside the sensor, it must be powered with 3 - 5V to function. Contrast this to photocells and FSRs where they act like resistors and thus can be simply tested with a multimeter.

Here we will connect the detector as such:

  • Pin 1 is the output so we wire this to a visible LED and resistor
  • Pin 2 is ground
  • Pin 3 is VCC, connect to 3-5V

When the detector sees IR signal, it will pull the output low, turning on the LED - since the LED is red its much easier for us to see than IR!

We will use 4xAA 1.3V batteries (I use NiMH) so that the voltage powering the sensor is about 4V.

2 batteries (3V) may be too little. 3 Batteries should be fine if you have a triple-AA holder

You can also get 5V from a microcontroller like an Arduino if you have one around. Ground goes to the middle pin.

The positive (longer) head of the Red LED connects to the +6V pin and the negative (shorter lead) connects through a 200 to 1000 ohm resistor to the first pin on the IR sensor.

Now grab any remote control like for a TV, DVD, computer, etc. and point it at the detector while pressing some buttons, you should see the LED blink a couple times whenever the remote is pressed

This guide was first published on Jul 29, 2012. It was last updated on Sep 21, 2018. This page (Testing an IR Sensor) was last updated on Jun 17, 2018.