Arduino Nano · IR Receiver

Arduino Nano IR Receiver Simulator: Wiring, Code and a Live Circuit

This is a 38 kHz IR receiver wired to an Arduino Nano with a remote control beside it, decoded live with the IRremote library: open it in the editor, press a button on the remote, and the serial monitor prints its command code.

Three wires to the receiver: power, GND, and OUT to pin 2. The remote speaks NEC, the protocol of most cheap kit remotes.

Run it in the editor Read the code

5 V logic
Library: IRremote.hpp
OUT on pin 2
NEC protocol, 38 kHz

Arduino Nano · IR Receiverlive0.000 s 0.00x

Click to open it in the editor

The circuit itself, running on the simulator with the sketch below. Press what can be pressed; click anything else to open it in the editor.

Wiring the IR Receiver to the Arduino Nano

Every connection in the circuit above, with the board’s own pin names.

IR Receiver pin	Arduino Nano pin	Why
VCC	5V	The VS1838B-style receiver runs from 2.7 to 5.5 V.
GND	GND	Ground.
OUT	pin 2	Low while a 38 kHz burst arrives, high otherwise: the demodulated code.
IR (light)	The remote	In the editor the infrared light path is drawn as a gray wire from the remote.

The receiver runs from the Arduino Nano’s 5V pin and its output idles at 5 V, which the board reads directly.

Pins to leave alone on the Arduino Nano

A6 and A7 are analog only: pinMode(A6, OUTPUT) does nothing and digitalRead(A7) is not there to call. D0 and D1 are the USB serial port.

On a real bench

The Nano plugs into the breadboard itself, straddling the center channel, so the IR Receiver goes in a few columns along and every connection is a short jumper. The silkscreen labels its pins D2 to D13 and A0 to A7; in code D2 is simply 2. A Nano clone with a CH340 USB chip needs that driver on a real computer.

The code

The sketch the circuit above runs. Open it in the editor, change a line and press Run: it compiles in your browser.

IR receiver on Arduino Nano pin 2

#include <IRremote.hpp>

const int IR_PIN = 2;   // OUT, pin 2

void setup() {
  Serial.begin(9600);
  IrReceiver.begin(IR_PIN);
  Serial.println("Point the remote and press a button");
}

void loop() {
  if (IrReceiver.decode()) {
    if (!(IrReceiver.decodedIRData.flags & IRDATA_FLAGS_IS_REPEAT)) {
      Serial.print("Command: 0x");
      Serial.println(IrReceiver.decodedIRData.command, HEX);
    }
    IrReceiver.resume();   // ready for the next one
  }
}

IrReceiver.begin(IR_PIN) starts the IRremote library listening on the pin. decode() returns true once a whole code has arrived, and decodedIRData.command holds the button’s command byte, 0x47 for the button pressed in this demo.

Holding a button makes an NEC remote send short repeat frames, which the library flags with IRDATA_FLAGS_IS_REPEAT. The sketch prints only the first frame of each press. resume() must be called after each code or nothing more is decoded.

Serial.begin(9600) opens the serial monitor. Serial is the USB port, as on the Uno; a clone with a CH340 chip needs that driver on a real computer, which the simulator does not.

Common mistakes with the IR Receiver on the Arduino Nano

Old IRremote code

Sketches written for IRremote 2.x use IRrecv irrecv(pin), irrecv.enableIRIn() and results.value. Version 3 and later use IrReceiver and decodedIRData, as here. Mixing the two is the most common reason an IR sketch will not compile.

Forgetting resume()

After decode() returns true, the library holds the code until resume() is called. Leave it out and the first button press is the only one you ever see.

Picking A6 or A7

A6 and A7 look like the other analog pins but are inputs to the ADC and nothing else. the receiver output on either of them never sees a digital level. Any of D2 to D13 or A0 to A5 works.

Questions and answers

Can I simulate an IR remote with an Arduino Nano?

Yes. The circuit at the top of this page is an Arduino Nano with a IR receiver and remote, running in your browser on a simulated ATmega328P. Click a button on the simulated remote: it sends a real NEC frame, which the receiver demodulates onto the pin. Press Run it in the editor to change the wiring or the code; it is free and needs no account.

How do I find my remote’s codes?

Run this sketch and press each button: the command printed is the code to compare against. Address and command are both in decodedIRData if you need to tell two remotes apart.

Why does every press print FFFFFFFF?

That is the repeat code of an NEC remote as old versions of the library reported it. The current library flags repeats instead, which the sketch checks.

Which receiver is this?

A three-pin 38 kHz demodulating receiver like the VS1838B or TSOP38238. Check the pin order on yours: it differs between makers.

Build your own IR Receiver project

Open this circuit in the editor, change the wiring or the code, and keep your version in a free account.

Start building free Open the editor