Grove - IR (Infrared) Receiver uses the Vishay TSOP38238 to receive 38 kHz-modulated infrared remote-control signals. It delivers demodulated digital pulses to a microcontroller, where software decodes the protocol and command. This module receives infrared signals; it does not transmit them.

Features

• TSOP38238, 38 kHz reception: Designed for modulated infrared remote-control signals.
• Integrated signal conditioning: Photodetection, amplification, AGC2, filtering, and demodulation in one receiver.
• MCU-friendly digital pulses: Active-low output for timing capture and software decoding.
• Grove digital connection: 3.3–5 V module supply with a four-wire Grove connector.

How It Works

A remote control switches its infrared LED on and off at approximately 38,000 cycles per second during a carrier burst. Bursts and gaps form the timing pattern used by a remote-control protocol. 38 kHz is the modulation carrier frequency, not the infrared light frequency or the data bit rate.

The receiver filters the incoming signal and removes the 38 kHz carrier. Its SIG output is normally HIGH and goes LOW during a valid detected burst. The output represents the burst envelope, not the original 38 kHz waveform.

The microcontroller measures pulse and gap durations to decode the protocol, address, and command. The TSOP38238 demodulates the signal; it does not decode button commands by itself. A LOW level alone does not mean a data bit of 0 or a particular button.

AGC2 and Signal Compatibility

The TSOP38238 uses AGC2 (automatic gain control). Together with optical and electronic filtering, AGC adjusts receiver sensitivity to help suppress interference from ambient light and other unwanted signals. Strong ambient light or interference can still reduce reception range; immunity is not absolute.

Use a compatible remote-control format with a 38 kHz carrier. Custom transmitters must meet the TSOP382 datasheet requirements for carrier bursts, gaps, and duty cycle. Continuous infrared illumination or an uninterrupted carrier is not a substitute for a correctly modulated remote-control message. Compatibility also depends on the MCU decoding software; not every infrared remote or protocol is supported.

Specifications

GPIO compatibility: For a 3.3 V microcontroller, power this module from 3.3 V. Do not assume the SIG output from a 5 V-powered module is safe for a 3.3 V-only GPIO; check the host input limits and use level shifting if required.

Quick Start

1. Connect VCC and GND to a compatible supply, and SIG to a digital input supported by your IR receive library. Leave the white NC wire unconnected.
2. Follow the Grove - Infrared Receiver Wiki for wiring and the existing Arduino raw-timing capture example.
3. Aim a compatible remote control at the receiver and press a button. A protocol-decoding sketch can report the protocol, address, and command when supported. The Wiki raw-capture sketch reports pulse timings rather than decoded button values.

A separate Grove - Infrared Emitter is optional for building your own transmit/receive pair; it is not required when receiving a compatible handheld remote.

Applications

• Remote-control button input for DIY electronics
• Infrared-controlled robots and interactive projects
• Custom short-range infrared communication using compliant burst formats

This is not a PIR motion sensor, infrared thermometer, distance sensor, or a receiver intended for continuous-beam detection.

Part List

Resources

• Vishay TSOP38238 / TSOP382 series datasheet — receiver operation, electrical specifications, and suitable data formats.
• Grove - Infrared Receiver Wiki — wiring, Arduino examples, and design files.
• Grove Sensor family
• New to Grove? Read Preface - Getting Started and Introduction to Grove.