IR Transceiver 38KHz 940nm JST-PH 2mm

IR Transmitter and Receiver with Stemma JST-PH 2mm connector (940nm Transmitter + 38kHz Receiver)

Were you looking for a high-power infrared transmitter board or a super-sensitive infrared receiver board? But if, instead of buying two boards, you’d prefer one that performs both functions, this is the board for you! This Adafruit breakout board is an ‘Infrared Transceiver’, so it is capable of transmitting and receiving remote control data at 940nm in a handy solderless package.

Please note that this board is specifically designed to receive IR remote control signals at 940nm and 38KHz; it is not suitable for proximity detection or other signals at different frequencies. The signal must be read by a microcontroller capable of receiving pulses, so ensure it supports IR receiver connectivity and decoding. Sometimes it is necessary to use special code or specific pins.

Important Note: To make this board easy to use, it includes both solder pads and a connector for a 4-pin JST-PH cable (the cable is not included with this product). Although Adafruit products often use JST-PH cables for I2C, this board does not use I2C. The white wire carries data from the microcontroller to be emitted via the IR LED, while the green wire transmits the demodulated remote signal data to the microcontroller. The black wire is ground, while the red wire is 3V-5V power and logic level.

The transmitter section uses the same circuit diagram and configuration as the breakout board “High Power IR LED Emitter“, which features an N-channel FET driver that supplies a current of 100mA–200mA through each LED, enabling coverage of distances in excess of 10 metres. One LED is oriented vertically and the other horizontally, ensuring optimal coverage. When powered at 5V, the board draws approximately 200mA per LED (400mA in total) during operation. When powered at 3V, the board draws approximately 100mA per LED (200mA in total). As infrared light is invisible to the human eye, a small yellow LED labelled “IN” is included, which flashes when the IR LEDs are active.

For the receiving section, the same “vertical” IR sensor used in the “IR Receiver” breakout board is employed. This sensor is designed to recognise signals modulated at 38 kHz and with a wavelength of 940 nm. The demodulated IR envelope is sent to the pin labelled “OUT” and must be decoded by your microcontroller. To aid debugging, there is a second yellow LED labelled “OUT”, which flashes when data is received.

This product is supplied as a fully assembled and tested PCB, but does not include the cable for the STEMMA connector. No soldering is required to use it, but you will need to obtain a 4-pin STEMMA JST PH cable with a 2mm pitch. Alternatively, if you prefer to solder, there is a 0.1″ header for power, ground and signals.

Technical details

Product dimensions: 25.5×17.7×7.2mm / 1.0″×0.7″×0.3″
Product weight: 2.0g / 0.1oz

Further information

Main guide: Adafruit IR Transmitter/Receiver.

Adafruit name: IR Remote Transceiver JST PH 2mm – Emitter + Receiver [ADA5990]