To begin with, this project uses RF 433MHz module and one Arduino work like transmitter and other like receiver.
When we press button on transmitter side, LED on receiver side go ON or OFF and also this RF Transmitter Receiver Circuit with Arduino Uno is very simple.
In addition, circuit is good project for new beginners, but its range is small but enough for small hobby work.
Arduino Code:
// Transmitter code
int button = 7;
int led = 13;
int txPin = 12;
void setup() {
pinMode(button, INPUT_PULLUP);
pinMode(led, OUTPUT);
pinMode(txPin, OUTPUT);
}
void loop() {
int state = digitalRead(button);
if(state == LOW){
digitalWrite(txPin, HIGH);
digitalWrite(led, HIGH);
} else {
digitalWrite(txPin, LOW);
digitalWrite(led, LOW);
}
}
Arduino code receiver side:
// Receiver code
int led = 13;
int rxPin = 11;
void setup() {
pinMode(led, OUTPUT);
pinMode(rxPin, INPUT);
}
void loop() {
int value = digitalRead(rxPin);
if(value == HIGH){
digitalWrite(led, HIGH);
} else {
digitalWrite(led, LOW);
}
}Coding Explanation:
- INPUT_PULLUP used for button so wiring is easy.
- When button pressed then pin becomes LOW.
- Transmitter sends HIGH on pin 12.
- Receiver reads pin 11.
- If HIGH then LED is ON.
- If LOW then LED is OFF.
- Very simple communication logic.
Circuit Working for RF Transmitter Circuit :
Parts List for Transmitter Circuit:
| Components | Quantity |
|---|---|
| Resistor | |
| 220Ω 1/4 watt | 1 |
| 10k 1/4 watt | 1 |
| Semiconductors | |
| Arduino Uno | 1 |
| RF Transmitter Module | 1 |
| Push Button | 1 |
| LED any 5mm | 1 |
First, the transmitter Arduino reads the push button and when the user presses the button, the input pin becomes LOW, and the Arduino sends a HIGH signal to the RF transmitter data pin.
The RF transmitter then transmits this HIGH signal through the air as a radio signal.
If we do not press the button, the Arduino instead sends a LOW signal, and the LED on the transmitter indicates the button status.
So transmitter only send simple ON or OFF signal.
How to Build RF Transmitter Circuit:
To build a RF Transmitter Circuit with Arduino Uno following are the steps to follow:
- First, assemble all the parts as shown in circuit diagram.
- Next, RF Transmitter VCC pin goes to Arduino 5V, RF Transmitter GND pin goes to Arduino GND and RF Transmitter DATA pin goes to Arduino digital pin 12
- Then push button one pin goes to Arduino 5V and push button other pin goes to Arduino digital pin 7
- Now connect 10k resistor from pin 7 to GND
- After that, LED positive end connect to Arduino pin 13 and LED negative connect to 220 ohm resistor to GND
- Finally, Arduino 5V pin connect to breadboard positive line and Arduino GND pin connect to breadboard ground line
Circuit Working for RF Receiver Circuit:
Parts List for Receiver Circuit:
| Components | Quantity |
|---|---|
| Resistor | |
| 220Ω 1/4 watt | 1 |
| Semiconductors | |
| Arduino Uno | 1 |
| RF Receiver Module | 1 |
| LED any 5mm | 1 |
Receiver module take radio signal from air and it give this signal to Arduino data pin and then Arduino read HIGH or LOW from receiver pin.
Also, if Arduino receive is HIGH then it turns LED ON and if receive is LOW then it turns LED OFF and then receiver only decode simple ON/OFF with no coding used.
So LED show the received state immediately.
How to Build RF Receiver Circuit:
To build a RF Receiver Circuit with Arduino Uno follow the below steps:
- First, assemble all the parts as shown in circuit diagram.
- Next, RF receiver VCC pin connect to Arduino 5V, RF receiver GND pin connect to Arduino GND and then RF Receiver DATA pin connect to Arduino digital pin 11.
- Then LED positive pin goes to Arduino pin 13 and LED negative pin goes to 220 ohm resistor to GND.
- Lastly, Arduino 5V pin goes to breadboard positive line and Arduino GND pin goes to breadboard ground line.
Formula with Calculation:
Below is a small formula from Ohms Law to find LED resistor.
R = (Vsource – Vled) / Iled
where,
- R means resistor value in ohms.
- Vsource means Arduino supply voltage 5V.
- Vled means LED forward voltage, around 2V for red LED.
- Iled means LED current, about 0.02A or 20mA.
Example:
R = (5V – 2V) / 0.02A
R = 3V / 0.02A
R = 150 ohms
So, we choose next safe value like 220 ohm resistor to keep LED safe.
Conclusion:
To conclude, this RF Transmitter Receiver Circuit with Arduino Uno is very simple and easy project and is also good for learning basic wireless control.
Furthermore, only few wires and two Arduino needed, further, we can use it for wireless switch, robot control and small remote; also this project is easy first step into wireless electronics.
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