ir sensor

IR Sensor

Infrared Obstacle Sensor Module

IR Sensor Module has builtin 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.

ir sensor module

IR Sensor Pinout

ir module pinout

Pin Description

Pin, Control IndicatorDescription
Vcc3.3 to 5 Vdc Supply Input
GndGround Input
OutOutput that goes low when obstacle is in range
Power LEDIlluminates when power is applied
Obstacle LEDIlluminates when obstacle is detected
IR EmitterInfrared emitter LED
IR ReceiverInfrared receiver that receives signal transmitted by Infrared emitter.


Board Size3.2 x 1.4cm
Working voltage3.3 to 5V DC
Operating voltage3.3V: ~23 mA, to 5V: ~43 mA
Detection range2cm – 30cm (Adjustable using potentiometer)
Active output levelThe output is "0" (Low) when an obstacle is detected

Onboard, Obstacle Detection LED indicator

Hardware Connections

-->  Vcc to 5V

-->  Gnd to Gnd

-->  Out to digital pin 7 (any digital pin)

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

  • 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.

IR Receiver TSOP1738

IR Receiver Pinout

IR Receiver Pinout

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