These RF modules are very popular among the Arduino tinkerers. The 433MHz is used on a wide variety of applications that require wireless control. These modules are cheap and you can use them with any microcontroller (MCU). In this project the transmitter is sending a message “Hello World!” to the receiver via RF. Those messages are being displayed in the serial monitor on the receiver.

Specifications RF 433MHz Receiver
- Frequency Range: 433 MHz
- Modulation: ASK
- Input Voltage: 5V

Specifications RF 433MHz Transmitter
- Frequency Range: 433MHz
- Input Voltage: 3-12V

You need the following components to make this circuit:
- 2x Arduino
- RF 433MHz Receiver/Transmitter
- Breadboard

Here’s the library you need for this project:
1. Download the RadioHead library
http://www.airspayce.com/mikem/arduino/RadioHead/RadioHead-1.41.zip
2. Unzip the RadioHead library
3. Install the RadioHead library in your Arduino IDE
4. Restart your Arduino IDE

The RadioHead library is great and it works with almost all RF modules in the market. You can read more about this project here.


Receiver Sketch

#include RH_ASK.h>
#include SPI.h> // Not actualy used but needed to compile

RH_ASK driver;

void setup()
{
Serial.begin(9600); // Debugging only
if (!driver.init())
Serial.println("init failed");
}

void loop()
{
uint8_t buf[12];
uint8_t buflen = sizeof(buf);
if (driver.recv(buf, &buflen)) // Non-blocking
{
int i;
// Message with a good checksum received, dump it.
Serial.print("Message: ");
Serial.println((char*)buf);
}
}


Transmitter Sketch - Sending Strings

#include RH_ASK.h>
#include SPI.h> // Not actually used but needed to compile

RH_ASK driver;

void setup()
{
Serial.begin(9600); // Debugging only
if (!driver.init())
Serial.println("init failed");
}

void loop()
{
const char *msg = "Hello World!";
driver.send((uint8_t *)msg, strlen(msg));
driver.waitPacketSent();
delay(1000);
}


Transmitter Sketch - Sending Sensor Data

#include RH_ASK.h>
#include SPI.h> // Not actually used but needed to compile

int SensorData;
char SensorCharMsg[4];

RH_ASK driver;

void setup()
{
Serial.begin(9600); // Debugging only
if (!driver.init())
Serial.println("init failed");
}

void loop()
{
SensorData=49;
itoa(SensorData,SensorCharMsg,10);
driver.send((uint8_t *)SensorCharMsg, strlen(SensorCharMsg));
driver.waitPacketSent();
delay(1000);
}