Project 7: DIY IR Remote Control Switch

Objective:

To build a DIY Infrared (IR) remote control switch that can turn ON/OFF an LED (or appliance) using a TV/DVD remote.

Components Required:

IR Receiver Module (TSOP1738)
Arduino Uno (or ATtiny85 for a compact design)
NPN Transistor (BC547)
Resistors – 220Ω, 1KΩ, 10KΩ
Relay Module (5V)
LED (or appliance)
Power Supply (9V Battery / 5V Adapter)
Breadboard & Wires
Any IR Remote (TV, DVD, etc.)

Circuit Diagram:

(A schematic can be designed in Fritzing or Tinkercad.)

Step-by-Step Instructions:

Step 1: Connect the IR Receiver Module

TSOP1738 has 3 pins:
- VCC → 5V
- GND → GND
- OUT → Arduino Digital Pin (D2)

Step 2: Decode the Remote Signals

Upload an IR decoding sketch to Arduino using the IRremote library.
Open the Serial Monitor and press buttons on the remote.
Note down the unique HEX codes of the buttons.

Step 3: Control the LED/Relay

Program Arduino to toggle the LED/Relay when a specific IR code is received.

Step 4: Power the Circuit

Use a 9V battery or 5V adapter for stable operation.

Code for Arduino:

cpp
#include <IRremote.h>

int RECV_PIN = 2;
int LED = 7;
IRrecv irrecv(RECV_PIN);
decode_results results;

void setup() {
  Serial.begin(9600);
  irrecv.enableIRIn();  
  pinMode(LED, OUTPUT);
}

void loop() {
  if (irrecv.decode(&results)) {
    Serial.println(results.value, HEX);
    if (results.value == 0xFFA25D) { // Replace with your remote's button code
      digitalWrite(LED, !digitalRead(LED)); // Toggle LED
    }
    irrecv.resume();
  }
}

How It Works:

The IR receiver detects remote signals.
Arduino decodes the signal and checks the button code.
If the button matches, it toggles the LED/Relay ON or OFF.
The appliance/light operates like a remote-controlled switch.

Customization Ideas:

💡 Control multiple appliances using different remote buttons.
💡 Use ATtiny85 for a compact and low-power version.
💡 Add a display to show which device is ON/OFF.