TSOP1738 IR Receiver Module
38kHz IR receiver for decoding signals from standard infrared remote controls.
Wiring & code for
TSOP1738 practical reference
A demodulating IR receiver tuned to 38kHz, used to decode signals from standard infrared remote controls. Rather than just detecting raw infrared light, the TSOP1738 internally filters and demodulates the 38kHz-modulated carrier that virtually all consumer IR remotes use, rejecting ambient light noise and outputting a clean digital pulse train that directly matches the original transmitted code — making it the standard receiver for universal remote clone projects, IR-controlled robots, or capturing existing remote codes for later playback.
Key specifications
- Sensor type: TSOP1738 demodulating infrared receiver, tuned to a 38kHz carrier frequency
- Operating voltage: 2.5V–5.5V DC
- Operating current: ~1.5 mA typical, low standby current
- Carrier frequency: 38kHz (matches the vast majority of consumer IR remote controls)
- Output: Active-LOW demodulated digital signal — pulses LOW when a matching 38kHz-modulated IR signal is received
- Range: ~10-15m typical for standard remote-control transmission power
- Ambient light rejection: Built-in filtering rejects sunlight and normal indoor lighting noise that would otherwise interfere with detection
- Interface: Single digital output pin, typically read using an IR-remote decoding library (e.g. IRremote)
Pinout and connection notes
Add a small decoupling capacitor (e.g. 10-100µF) across VCC and GND close to the sensor if experiencing unreliable readings, since the internal AGC circuit can be sensitive to power supply noise; libraries like IRremote handle the pulse-timing decode automatically once wired to a digital input pin. Confirm the carrier frequency matches your target remote — 38kHz covers most consumer electronics, but a few remotes (particularly some Japanese TV brands) use 36kHz or 40kHz and need a differently-tuned TSOP variant.
- OUT: Demodulated digital signal output, active LOW — connect to a digital input pin
- GND: Ground
- VCC: Power, 2.5–5.5V DC
Integration checklist
- Confirm the exact part number and breakout-board revision.
- Verify supply voltage, current demand, logic levels, and signal direction against the datasheet.
- Check controller pin assignments and bus address or interface mode against the example code.
- Power up with external loads disconnected, then test signals before full integration.
- If readings or communication fail, check power and ground first, then pin mapping, interface settings, and library initialization.
Troubleshooting and reproducibility
Record the board used, wiring, library/version, supply arrangement, and measured behavior. Use the selected board-specific wiring example as the source of truth. Never assume visually similar modules share identical voltage tolerance or pin order.