Arduino
IR Remote: A beginners tutorial on Receiving and transmitting IR Remote
Control Signals using an IR LED, and IR receiver connected to an Arduino Uno.
Introduction
How to create an Arduino IR remote control using an IR LED and IR
recevier. You have many IR (Infra Red) Remotes in your home which allow
you to
control the TV, air conditioners, garage door openers, etc. This
tutorial will show you how to read the code that your IR remote makes,
and replicate it using an Arduino.
How do IR remotes work?
IR remote controls work by sending out unique bursts of infrared light
for each button pressed on the remote (using an Infrared light emitting diode). The receiving device, whether a
TV, AC unit, or other appliance, contains an IR sensor that can
recognize these coded signals. It then carries out the associated
function like changing channels or adjusting temperature settings.
How to detect IR remote light
The tutorial uses an IR sensor module which contains an infrared
photodiode and internal conditioning
circuit. You get the decoded digital output from one pin - all very
convenient - and all you need to do is get the Arduino to interpret the
protocol (the sequence of formatted digital data) from the IR sensor -
just use the suggested library.
There are many different IR receiver modules, but most will work just
fine with this tutorial. However make sure they are tuned to operate at
38~39kHz - this is the diode modulation frequency. To transmit a
digital "1", the diode is not just turned on for a while, it is turned
on and off at 38kHz for a set period of time (this is part of sunlight
rejection - the receiver can be tuned to reject anything but 38kHz
oscillation).
The one used in this tutorial is on the Keys-22 breakout board and is the TL1838
Why not use 'just an IR photodiode' to detect IR?
These modules have been developed over years and include frequency
sensitive amplifiers and ambient sunlight rejection circuits - it means
they can work up to 18m. In short don't try to make one of these using
an IR receiver diode - all the problems in creating a reliable detector
are solved in the IR Sensor module.
Note: There is one good use of an IR LED and IR receiver diode - and that is detecting blood flow i.e. creating a heart rate plot.
What this tutorial does
With an Arduino controlling such an IR sensor module and also controlling an IR LED, you have the
ability to both receive from and transmit to other IR devices. We can
input codes detected from a physical remote. Or our code can output
codes to control appliances without a physical remote of our own.
In this guide, we'll show you how to wire an IR sensor module to an
Arduino and code it for bidirectional IR communication. You'll learn to
receive signals and also emit your own codes to remotely trigger
devices. This opens up plenty of possibilities to control additional
systems through the infrared protocols that are included within Arduino
libraries.
Getting Started with an Arduino IR Remote
In this beginner-friendly tutorial, we'll show you how to use an
Arduino IR remote sensor with your Arduino Uno board to receive signals from a
standard TV or air conditioner remote control. By decoding the IR
pulses, you'll be able to control Arduino projects and more with a
simple remote.
Required Components
Arduino Uno or Nano board
IR Sensor Module
Breadboard
Jumper wires
Example remote control (from TV, AC, etc)
An IR LED
A push button
A 100 Ohm resistor.
Arduino IR remote: Circuit Diagram
Ground (0V) and supply voltage (5V) are connected from pins in the
lower
pin header of the Arduino Uno, while the IR sensor is connected to pin
10
of the upper rail and the IR diode is connected to pin 9 of the upper
rail via the 100 Ohm resistor - make sure the flat side of the IR diode
(denoting the cathode) goes to ground. The push button is connected to
pin 2 on one side, and ground on the other.
Diagram using fritzing
Diagram using fritzing
Libraries needed
The library you need to install is "IRremote".
Installing an Arduino Library with IDE
Install the library as follows:
1st method:
Click the menu bar and follow the menu items:
Sketch-->Include Library-->Manage
Libraries...
2nd method:
Click the ICON on the left that looks like a set of books.
The library manager appears on the left of the screen.
In the search box type "IRremote". Now click the install button.
Arduino IR remote: Example Sketch
What it does
The following Arduino IR remote sensor example code will receive a code from
your remote - press any button and the serial monitor will display the
data for that button.
Warning: Not all
protocols are supported - if it fails try a different remote control
unit (or look at the github source for IRremote - it has some ideas for
other protocol solutions).
When you press your own button on the breadboard, it will spit out
the
same code with the same protocol, address and code as the remote (these
values were are stored in variables: irprotocol, iraddress,
ircode on IR recevied action).
It is a simple repeater, but demonstrates the fundamental use of the
library so you can use it for more complex projects. For example:
IR Remote Controlled LEDs/Motors
IR Remote Home Automation
IR Repeater
Universal Remote
IR Message Decoding
TV Remote Controlled Car
IR Remote Power Relay
You can copy and paste the code below into the Arduino IDE (in a new
sketch) replacing everything that is in the new sketch window (See "Uploading the code" below).
IrReceiver.resume(); // Do it here, to preserve raw data for printing with printIRResultRawFormatted()
}else{
IrReceiver.resume(); // Early enable receiving of the next IR frame
IrReceiver.printIRResultShort(&Serial);
IrReceiver.printIRSendUsage(&Serial);
Serial.print("Command ");
Serial.println(IrReceiver.decodedIRData.command);
irprotocol = IrReceiver.decodedIRData.protocol;
iraddress = IrReceiver.decodedIRData.address;
ircommand = IrReceiver.decodedIRData.command;
}
Serial.println();
IrReceiver.resume(); // Receive the next value
}
// You could use millis delay code but this works as
// IRremote library is interrupt driven.
// In general don't use delay() this is beginners code.
int reading1 = digitalRead(buttonPin);
delay(50);
int reading2 = digitalRead(buttonPin);
if(reading1==reading2){ // Press or release is same as 50ms ago.
buttonState = reading1;
if(buttonState == HIGH && // Update on correct transition - button release.
previousButtonState == LOW){
// Flash built-in LED
digitalWrite(ledPin, HIGH);
delay(100);
digitalWrite(ledPin, LOW);
// Send saved IR code
sendIRCode(code);
} // went high
previousButtonState = buttonState;
} // r1 == r2
} // loop
Short Code Explanation
The code receives IR codes from a receiver module using the IRRemote library to create an Arduino IR remote project.
It defines pins for the receiver, LED, IR LED and button.
Global variables store the received protocol, address and command.
Setup initializes the pins and starts code receiving/sending.
Loop checks for received codes and prints values to serial monitor.
It stores the protocol, address and command in global variables.
Button press is checked and LED flashes on press.
On button press, the stored command value is sent via IR LED.
Arduino IR remote: Detailed explanation
The code first includes the IRremote library. This library provides functions and classes to encode and decode IR signals.
It then declares some global variables that will be used throughout the code:
irPin: The pin number connected to the IR receiver module
ledPin: The pin for the built-in LED
irLedPin: The pin connected to the IR LED
buttonPin: The pin for the button
It also declares variables to store the received protocol, address and command:
irprotocol
iraddress
ircommand
The setup() function runs once on startup. It initializes the LED, IR
LED and button pins as outputs or inputs. It then begins initialization
of the IRreceiver and IRsender objects from the IRremote library. This
prepares them to receive and transmit IR signals.
The main loop() is where the logic happens. It first calls
IrReceiver.decode() to check if a new code was received. If a code was
received, it prints out details like the protocol and address.
Importantly, it stores the received values in the global variables.
Next, the button state is checked. If pressed, the stored command
value is passed to sendIRCode(). sendIRCode() first flashes the LED for
feedback. It then uses the IRsender object to transmit the code, using
the stored protocol, address and command.
By receiving codes, storing the important values, and retransmitting
on demand, this demonstrates the basic process of IR reception and
retransmission with the IRremote library.
Arduino IR remote: Uploading the Code
There are a few steps to uploading the code using the Arduino IDE:
Connect the Arduino Uno to the PC with a USB cable.
Select the Arduino Uno hardware.
Open a new sketch.
Paste the code above into the new page (overwrite everything).
Press the upload button (right arrow at top).
You can find a more detailed tutorial on the Arduino IDE page.
Testing the Circuit
Connect up as shown, and point at IR receiver on the breadboard e.g. use your TV remote - and point it at the
sensor. After that, Press the button on the solderless breadboard to re-transmit
that code. If it does not work your remote may have an unsupported
protocol. The solution is to use another remote, or use a different IR
library.
Look at the Serial monitor output to see what was received to see
which protocol your remote is using, and other received data e.g. address
and command.
Making it reliable
If the device you are controlling does not react very well, then
change the code to increase the repetitions of the output code. So for
instance, changing the '0' to a '3' in the statement below, will cause 3
repetitions of the output code. This line is within the function sendIRCode().
The reason this works is that in all IR remote codes there is a bit
within the sent data that indicates if a key-press-has-changed. The
Receiving device can understand, that if it receives multiple IR codes,
that you are holding the button down - not that you want to turn the
television on and off twenty times a second!
Arduino IR remote: Conclusion
This concludes the basic tutorial on using an Arduino IR remote sensor to
receive and transmit infrared signals. With just a few inexpensive
components, you've built a system that can detect remote control codes
and retransmit them to trigger associated actions.
The skills learned here provide a foundation for many possible
extension projects. Some ideas include building a universal remote to
control multiple devices, creating an IR-based home automation system,
or adding IR controls to robots or other Arduino projects.
The IRremote library also supports decoding protocols for many common
remotes, so with further exploration you can receive codes from a wide
range of sources. Combining IR reception with other sensors and
actuators opens up creative possibilities.
I hope this tutorial helped demonstrate the basic functionality of an
Arduino IR remote sensor and IR LED. Please feel free to experiment further and let me
know if you have any other questions.
Written by John Main who has a degree in Electronic Engineering.
Note: Parts of this page were written using claude-instant
as a research assistant.
How to get accurate DHT22 digital humidity sensor readings with an Arduino. Did you know it also measures temperature as Well? Find out why, in this page...
A PIR sensor lets your Arduino sense movement without contact. This tutorial covers PIR sensor basics, connecting one to an Arduino board and coding a motion detector.
Arduino Hall Effect Sensor: Add magnetic sensing superpowers to your Arduino projects with an easy-to-use hall effect sensor. With full code and layout...
The tutorial uses an IR sensor module which contains an infrared
photodiode and internal conditioning
circuit. You get the decoded digital output from one pin - all very
convenient - and all you need to do is get the Arduino to interpret the
protocol (the sequence of formatted digital data) from the IR sensor -
just use the suggested library.
With an Arduino controlling such an IR sensor module and also controlling an IR LED, you have the
ability to both receive from and transmit to other IR devices. We can
input codes detected from a physical remote. Or our code can output
codes to control appliances without a physical remote of our own.
Comments
Have your say about what you just read! Leave me a comment in the box below.
Don’t see the comments box? Log in to your Facebook account, give Facebook consent, then return to this page and refresh it.