Summary of Connecting an IR Sensor Using Arduino
The article explains how to set up an IR sensor circuit similar to a light sensor, with the addition of IR LEDs and IR detectors needing 5V and ground connections. It details assembling IR LEDs into housings, correctly placing them and IR detectors on a breadboard, noting the importance of polarity. Resistors (2kΩ and 220Ω) are used to limit current through the LEDs, especially critical since IR light is invisible to the naked eye, making it hard to verify functionality visually.
Parts used in the IR Sensor Project:
- IR Detectors (2x)
- IR LEDs in housings (2x)
- 2kΩ resistors (2x)
- 220Ω resistors (2x)
- Red jumper wires (2x)
- Black jumper wires (2x)
- Signal jumper wires (2x)
Schematic
Since the IR Sensor uses a light sensor, the schematic is very similar to that of the light sensor. The only difference is the addition of an IR LED and that the IR detector requires connection to 5V and ground.
Breadboard Setup
To setup the sensors you will need:
- 2x IR Detectors
- 2x IR LEDs in housings
- 2x 2kΩ resistors (red-black-red)
- 2x 220Ω resistors (red-red-brown)
- 2x red jumper wires
- 2x black jumper wires
- 2x signal jumper wires (can be of any color)
First we need to make sure that the IR LEDs are in their housings :
1) Insert IR LED into larger housing part with leads sticking out.
2) Press the LED firmly into the housing.
3) Place the smaller housing part over the LED.
Placing the IR LEDs
Now we can place the IR LEDs into the breadboard. Note that the anode (longer lead, rounded edge) is the positive side and the cathode (shorter lead, flat edge) is the negative side. Reversing the polarity may damage the LED.
Placing the IR Detectors
Now we can place the IR Detectors into the breadboard. The middle prong of the collector should be on the same bus as the LED’s cathode (in order to tie it to Ground).
Resistors
Remember, the IR LED’s are still a form of LED and will need a resistor in place to limit the amount of current flowing through them. This is especially important to remember with infrared LEDs because the wavelengths of light they emit are not visible to the human eye; it may be difficult to determine if they are working or not.
For more detail: Connecting an IR Sensor Using Arduino
