Infrared (IR) communication is a popular method for wireless communication, commonly used in remote controls for televisions, air conditioners, and other home appliances. In this article, we will explore how to create an IR transmitter using an Arduino, which can be used to control various devices.

Understanding IR Communication

IR communication involves the transmission of data using infrared light. An IR transmitter sends out infrared light pulses, which are detected by an IR receiver. The data is encoded in the pattern of these pulses.

Components Required

• Arduino board (e.g., Arduino Uno)
• IR LED
• Resistor (220 ohms)
• Breadboard and jumper wires
• IR receiver module (optional for testing)

Circuit Diagram

1. Connect the long leg (anode) of the IR LED to a digital pin on the Arduino (e.g., pin 3).
2. Connect the short leg (cathode) of the IR LED to one end of the resistor.
3. Connect the other end of the resistor to the ground (GND) on the Arduino.

Installing the IRremote Library

To simplify the process of sending IR signals, we will use the IRremote library. Follow these steps to install it:

1. Open the Arduino IDE.
2. Go to Sketch > Include Library > Manage Libraries.
3. Search for "IRremote" and install the library by shirriff.

Sample Code

Here is a sample code to send an IR signal using the Arduino:

#include <IRremote.h>

IRsend irsend;

void setup() {
  Serial.begin(9600);
}

void loop() {
  // Send a Sony TV power command
  irsend.sendSony(0xa90, 12);
  delay(2000); // Wait for 2 seconds before sending the signal again
}

Explanation

• The IRsend object is used to send IR signals.
• In the loop() function, the sendSony() method sends a Sony TV power command. The first argument is the command code, and the second argument is the number of bits in the command.
• The delay(2000) function pauses the loop for 2 seconds before sending the signal again.

Testing the IR Transmitter

To test the IR transmitter, you can use an IR receiver module connected to another Arduino. Here is a simple receiver code to print the received IR signal to the Serial Monitor:

#include <IRremote.h>

IRrecv irrecv(11); // Connect the output of the IR receiver to pin 11
decode_results results;

void setup() {
  Serial.begin(9600);
  irrecv.enableIRIn(); // Start the receiver
}

void loop() {
  if (irrecv.decode(&results)) {
    Serial.println(results.value, HEX); // Print the received value in HEX format
    irrecv.resume(); // Receive the next value
  }
}

Conclusion

Creating an IR transmitter with Arduino is a straightforward process that can be accomplished with a few components and the IRremote library. This setup can be used to control various IR-enabled devices, making it a versatile tool for home automation projects.