Circuit Documentation

Summary of the Circuit

This circuit is designed to control an RF 433 MHz transmitter and an LED using an Arduino UNO microcontroller. The circuit includes a momentary push button switch that, when pressed, triggers the Arduino to send a signal through the RF transmitter and simultaneously light up an LED. The circuit is powered by a 9V battery, which is controlled by a rocker switch to turn the power supply on and off. A resistor is used in series with the LED to limit the current and protect the LED from damage.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

9V Battery

• Standard 9V battery used to provide power to the circuit.

Rocker Switch

• A simple on/off switch that controls the connection between the 9V battery and the circuit.

RF 433 MHz Transmitter

• A radio frequency transmitter that operates at 433 MHz for wireless communication.

Momentary Push Button Switch

• A switch that is only active when pressed, used to trigger an event in the circuit.

LED: Two Pin (red)

• A red light-emitting diode that illuminates when powered.

Resistor

• A 220 Ohm resistor used to limit the current through the LED.

Wiring Details

Arduino UNO

• 5V pin is connected to the +ve pin of the RF 433 MHz Transmitter.
• GND pin is connected to the - pin of the 9V Battery, -ve pin of the RF 433 MHz Transmitter, and pin2 of the Resistor.
• Vin pin is connected to the output pin of the rocker switch.
• D13 pin is connected to the cathode pin of the LED.
• D12 pin is connected to the Data pin of the RF 433 MHz Transmitter.
• D2 pin is connected to pin2 of the Momentary Push Button Switch.

9V Battery

• + pin is connected to the input pin of the rocker switch.
• - pin is connected to the GND pin of the Arduino UNO.

Rocker Switch

• input pin is connected to the + pin of the 9V Battery.
• output pin is connected to the Vin pin of the Arduino UNO.

RF 433 MHz Transmitter

• +ve pin is connected to the 5V pin of the Arduino UNO.
• -ve pin is connected to the GND pin of the Arduino UNO.
• Data pin is connected to the D12 pin of the Arduino UNO.

Momentary Push Button Switch

• pin2 is connected to the D2 pin of the Arduino UNO.
• pin4 is connected to the GND pin of the Arduino UNO through the Resistor.

LED: Two Pin (red)

• anode pin is connected to pin1 of the Resistor.
• cathode pin is connected to the D13 pin of the Arduino UNO.

Resistor

• pin1 is connected to the anode pin of the LED.
• pin2 is connected to the GND pin of the Arduino UNO.

Documented Code

void setup() {
  pinMode(2, INPUT_PULLUP); // Momentary switch connected to D2
  pinMode(12, OUTPUT);      // RF Transmitter Data connected to D12
  pinMode(13, OUTPUT);      // LED connected to D13
}

void loop() {
  if (digitalRead(2) == LOW) { // Check if the momentary switch is pressed
    digitalWrite(12, HIGH);    // Send signal via RF Transmitter
    digitalWrite(13, HIGH);    // Turn on LED
    delay(100);                // Debounce delay
    digitalWrite(12, LOW);     // Stop sending signal
    digitalWrite(13, LOW);     // Turn off LED
  }
}

The code is written for the Arduino UNO microcontroller. In the setup() function, the digital pins are configured: pin 2 as an input with an internal pull-up resistor, and pins 12 and 13 as outputs. The loop() function continuously checks the state of the momentary switch connected to pin 2. When the switch is pressed (logic LOW), the Arduino sends a HIGH signal to the RF transmitter on pin 12 and turns on the LED connected to pin 13. After a short delay to debounce the switch, it turns off both the RF transmitter and the LED.