RF 434MHz ASK Transmitter and Receiver

1. Description

This tutorial shows how to establish a basic RF communication link using cost effective wireless modules (434 MHz transmitter and receiver). The use of low-cost RF modules could be practical in systems with multiple remote sensors and/or other remote devices. On the other hand, this type of modules do not offer advanced security features as it might be the case for the more expensive RF modules.

Difficulty level: beginner.

2. Parts

– Transmitter:

– 1 x Standalone ATmega328P-PU w Reset Button and LED (or Arduino Uno R3);
– 1 x TWS-BS RF Transmitter Module (434 MHz);
– Breadboard + wires.

– Receiver:

– 1 x Arduino Uno R3;
– 1 x RWS-371 RF Receiver Module (434 MHz);
– Breadboard + wires.

Note. RF modules (transmitter and receiver) at other frequencies (i.e. 315 MHz) could be used as long as they match each other.

3. Schematics

– Transmitter:

(click to enlarge)

– Receiver:

(click to enlarge)

4. Assembly (breadboard)

– Transmitter:

(click to enlarge)

– Receiver:

(click to enlarge)


5. Code

The code implements a minimalist RF communication link between the two microcontrollers. It uses the RadioHead-1.74 library and is basically a slight variation of the original example code (included in the library) for the ASK transmitter and receiver.

ask_transmitter.ino – to be uploaded into transmitter’s microcontroller:

 

ask_receiver.ino – to be uploaded into receiver’s microcontroller:

6. Demo

7. Additional resources

Libraries:
– RadioHead-1.74: http://www.airspayce.com/mikem/arduino/RadioHead/

References:
– RadioHead Packet Radio library for embedded microprocessors: http://www.airspayce.com/mikem/arduino/RadioHead/
– RadioHead RH_ASK Class Reference
http://www.airspayce.com/mikem/arduino/RadioHead/classRH__ASK.html


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