IR-receiver

Kaluma library for IR (Infrared) receiver.

Wiring

Here is a wiring example for IR receiver. In this example we used TSOP1838 or TSOP38438 (38KHz).

Raspberry Pi Pico	IR receiver
3V3	VCC
GND	GND
GP15	OUT

Install

npm install https://github.com/niklauslee/ir-receiver

Usage

Here is an example code.

const {IRReceiver} = require('ir-receiver');
const pin = 15;
pinMode(pin, INPUT_PULLUP);
const ir = new IRReceiver(15);
ir.on('data', (data, bits) => {
  console.log(`data: ${data.toString(16)} (${bits} bits)`);
});

Example

This example shows how to transmit IR signals read from a remote controller.

Components

Part	Quantity	Note
Raspberry Pi Pico	1
Breadboard	1	mini
Push button	1
IR LED	1	940nm
IR receiver	1	TSOP38438 (or TSOP1838) 38KHz
Remote controller	1	NEC type (38KHz)
Jumper wires

Wiring

Raspberry Pi Pico	IR receiver	IR LED	Button
3V3	VCC		L1
GND	GND
GP15	OUT
GP16		anode
GP17		cathode
GP14			L2

Code

When you send IR signal to the IR receiver using a remote controller (38KHz), the signal pulse is stored in the memory variable. Then, it sends the stored IR signal whenever you press the button.

const {IRReceiver} = require('ir-receiver');

var memory = null;  // to store received IR signal
var recv = 15;      // pin for IR receiver
var led_pulse = 16; // pin for IR LED digital pulse
var led_pwm = 17;   // pin for IR LED 38KHz carrier
var btn = 14;       // pin for button

pinMode(recv, INPUT_PULLUP);
pinMode(led_pulse, OUTPUT);
pinMode(btn, INPUT_PULLDOWN);

// receive IR signal and save to memory
var ir = new IRReceiver(recv);
ir.on('data', (data, bits, pulse) => {
  console.log('IR signal received.');
  console.log(`- data: ${data.toString(16)} (${bits} bits)`);
  console.log(`- pulse(${pulse.length}): [${pulse.join(',')}]`);
  memory = pulse;
});

// send IR signal stored in memory
function send() {
  analogWrite(led_pwm, 0.5, 38000); // 38KHz
  pulseWrite(led_pulse, HIGH, memory);
  digitalWrite(led_pulse, LOW);
  console.log('Sent IR signal.');
}

// send signal when button pressed
setWatch(send, btn, RISING, 10);

References

API

Class: IRReceiver

IRReceiver(pin[, options])

pin <number>
options <object>
- timeout <number> Enough time to receive data in microseconds. Default: 100000.

Create an instance and ready to receive IR signals.

Event: 'data'

data <number> The received data.
bits <number> The size of data. (Many remote controller sends 32-bits data).
pulse <number[]> The raw pulse data.

Emitted when data is received.