Arduino and RF Transceiver Module - OnSpec Electronic, Inc

Wireless communication has become an integral part of our lives, whether it’s a TV remote or long-distance radio communication. By using RF modules (Radio Frequency Modules), we can easily and affordably implement wireless communication.

Arduino, on the other hand, is a cost-effective solution for microcontroller applications. With its open-source hardware and software, Arduino can be used in various applications with simple programming and hardware components.

By combining wireless communication with Arduino, we can create a wide range of applications such as remote-controlled cars, wirelessly operated robots, home automation systems, and simple data transfer.

In this project, we will design a system where two Arduino boards communicate with each other using RF modules.

Circuit Diagram

As this is a wireless communication project, the circuit consists of a transmitter part and a receiver part.

The circuit for the transmitter part is shown below:

And the circuit for the receiver part is shown below:

Components Required

Transmitter Part:

Arduino UNO (or any other Arduino board)
434 MHz Transmitter Module (or 315 MHz Module)
LED
1 KΩ Resistor
Prototyping board (breadboard)
Connecting wires
Power supply (adapter or battery)

Receiver Part:

Arduino UNO (or any other Arduino board)
434 MHz Receiver Module (or 315 MHz Module)
LED
1 KΩ Resistor
Prototyping board (breadboard)
Connecting wires
Power supply (adapter or battery)
RF Module

Component Description

Arduino UNO:

Arduino UNO is an affordable, open-source microcontroller board used for electronics prototyping. In this project, we will utilize two Arduino boards for wireless communication.

RF Module:

RF Module is a low-cost wireless communication module commonly used in various applications. It consists of a transmitter and a receiver that operate at a specific radio frequency range, typically 315 MHz or 434 MHz.

For this project, we are using a 434 MHz RF Transmitter-Receiver pair, which can communicate over distances of up to 40 meters.

Circuit Design

Transmitter Part:

The transmitter part consists of an Arduino UNO and the 434 MHz Transmitter module. An onboard LED can be used, but an external LED with a current-limiting resistor is also an option. The design of the transmitter part is as follows:

The RF Transmitter Module has 4 pins: VCC, GND, Data, and Antenna. VCC and GND pins are connected to the 5V and ground respectively. The data pin is connected to any digital input/output pin of Arduino. In this project, it is connected to Pin 12.

The antenna pin should be connected to a wire wound in the form of a coil.

Receiver Part:

The receiver part consists of an Arduino UNO and the 434 MHz Receiver module. An onboard LED can be used, but an external LED with a current-limiting resistor is also an option. The design of the receiver part is as follows:

The RF Receiver Module also has 4 pins: VCC, GND, Data, and Antenna. VCC and GND pins are connected to the 3.3V pin of the Arduino and ground respectively. The data pin is connected to Pin 12 of the Arduino.

An antenna similar to the one used in the transmitter module is connected to the antenna pin of the 434 MHz Receiver module. The onboard LED connected to the 13th pin of Arduino is used in the project, but an external LED can be used as well.

Working Process

In this project, we demonstrate RF communication between two Arduino UNO boards. The goal is to successfully transmit data between the RF Transmitter-Receiver modules using the microcontroller boards. Here’s how the project works:

Note: This project can be implemented with or without the use of a special library called “VirtualWire.h”. The project described here uses the library. However, if you prefer not to use the library, the receiver part of the circuit needs to be modified.

VirtualWire.h is a communication library created by Mike McCauley specifically for Arduino. It allows two Arduino boards to communicate with each other using RF modules. The library consists of several functions used for module configuration, data transmission, and reception.

In this project, the transmitter sends two characters: “1” and, after a brief delay, “0”. When the transmitter sends “1”, the LED on the transmitter side turns on. The receiver receives the data “1” through RF communication and turns on its LED accordingly.

Similarly, when the transmitter sends “0”, the LED on the transmitter side turns off. As a result, the receiver receives “0” and its LED also turns off.

Thus, the receiver imitates the actions of the transmitter.

Note: The project uses a special library called VirtualWire, which utilizes the microcontroller’s “Timer” feature. This may affect timer-related properties such as PWM. If you prefer not to use the library, you can refer to the above schematic for a similar implementation without any library.

The project includes sketches for both variants: one using the library and the other without.