What is the IR Sensor?
Infrared Obstacle Sensor Module
IR Sensor Module has built-in an IR transmitter and IR receiver that sends out infrared light and looks for reflected infrared light to detect the presence of any obstacle in front of the sensor module.
It is used to find obstacles and short & medium-range communication.
There is onboard a potentiometer to adjust the detection range. There is an Obstacle Detection LED indicator on the module board.
IR sensor transmits digital data (logical 1 and 0) in the form of infrared light. When the sensor gets logical 1 means LED ON and logical 0 means LED OFF.
The sensor has a very good and stable response even in ambient light or in complete darkness.
Must See:

IR Sensor Pinout
IR sensor has three pins are- VCC, GND, and Out. It also has a distance adjust potentiometer.

Pin Description
Vcc | 3.3 to 5 Vdc Supply Input |
GND | Ground Input |
Out | The output that goes low when an obstacle is in range |
Power LED | Illuminates when power is applied |
Obstacle LED | Illuminates when an obstacle is detected |
IR Emitter | Infrared emitter LED |
IR Receiver | The infrared receiver that receives signal transmitted by Infrared emitter. |
Specifications
Board Size | 3.2 x 1.4cm |
Working voltage | 3.3 to 5V DC |
Operating voltage | 3.3V: ~23 mA, to 5V: ~43 mA |
Detection range | 2cm – 30cm (Adjustable using potentiometer) |
Active output level | The output is “0” (Low) when an obstacle is detected |
Hardware Connections
- Vcc to 5V of Arduino.
- GND to GND of Arduino.
- Out to any digital pin of Arduino.
IR Transmitter
- For transmitting IR LED of wavelength 940 nm to 950 nm are commonly used.
- This IR LED transmits the data from one end to and at another end there is an IR receiver to receive the data.

IR Receiver TSOP1738
- At the receiver end, the IR receiver receives data at 38kHz of the carrier frequency.
- Mainly, TSOP Receiver is used to receive data which support various transmitted code.
- The data rate of TSOP1738 is up to 2400 bps.

