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Basics: Project 037a

Project name: RF 315/330/433 MHz XD-FST / XD-RF-5V Transmitter / Receiver - way to communicate between Arduinos

Tags: Arduino, RF 315/330/433 MHz XD-FST / XD-RF-5V Transmitter / Receiver, way to communicate between Arduinos

Attachments: library1, transmittersketch1, receiversketch1; library2, transmittersketch2, receiversketch2;

In this project, you needed these parts :

1.Aruduino Uno R3 (you can also use the other version of Arduino) 2 pcs

2.Arduino IDE ( you can download it from here  )

3.Jumper cables

4. RF 315/330/433 MHz XD-FST / XD-RF-5V Transmitter / Receiver module 1 pc

General

We will learn how to connect RF 315/330/433 MHz XD-FST / XD-RF-5V Transmitter / Receiver modules to Arduino board and use them.

Understanding the RF 315/330/433 MHz XD-FST / XD-RF-5V Transmitter / Receiver

The 433MHz is used on a wide variety of applications that require wireless control. Check that it's legal to operate low powered devices (25mW) in the 433MHz band without a licence in your country. If you're transmitting to (or on the same frequency as) a garage door opener / RC toy etc that you bought in your own country, it should be fine, provided you stick to the power limit.

315/330/433 MHz XD-FST / XD-RF-5V Transmitter / Receiver modules are very popular and, of course, cheap You can use them with any microcontroller (MCU).They work very well when the receiver and transmitter are close to each other. If you separate them too far you’ll loose the communication. The communication range will vary. It depends on how much voltage that you’re supplying to your transmitter module, RF noise in your environment and if you’re using an external antenna.

The use of an optional antenna will increase the effectiveness of your wireless communication. See on picture below.

Specification:

TX (Transmitter) Technical Specifications:

• Working voltage: 3V～12V
• Working current: max≤40mA (12V), min≤9mA(3V)
• Resonance mode: sound wave resonance (SAW)
• Modulation mode: ASK /OOK
• Working frequency: 315MHz-433.92MHz, customized frequency is available.
• Transmission power: 25mW (315MHz at 12V)
• Frequency error: +150kHz (max)
• Velocity: ≤10Kbps
• Self-owned codes: negative
• Transmit up to 90m in open area

RX (Receiver) Technical Specifications:

• Working voltage: 5.0VDC +0.5V
• Working current:≤5.5mA (5.0VDC)
• Working principle: single chip super regeneration receiving
• Working method: OOK/ASK
• Working frequency: 315MHz-433.92MHz, customized frequency is available.
• Bandwidth: 2MHz (315MHz, having result from testing at lowing the sensitivity 3dBm)
• Sensitivity: excel –100dBm (50Ω)
• Transmitting velocity: <9.6Kbps (at 315MHz and -95dBm)

Signals and connections of the RF 315/330/433 MHz XD-FST/XD-RF-5V Transmitter/Receiver

Transmitter (TX) pins:

ATAD (DATA) - output signal coded by first Arduino board

GND - should be connected to ground , (-) of power supply

VCC - should be connected to power supply +3V - +12V

Receiver (RX) pins:

DATA - there are two pins, it doesn't matter which one to connect to second Arduino board, as long as you use only one of the DATA pins.

GND - should be connected to second Arduino board ground pin

VCC - should be connected to second Arduino board 5V pin.

Build the circuit

The following picture shows the needed connections with the Arduino Uno 

Code

1. Sketches with RadioHead library:

Transmitter sketch / you will need to modify this line

const char *msg = "Welcome to Acoptex.com!!!";//you can change this message to yours, do not forget to change number of symbols in receiver sketch

Receiver sketch / you will need to modify this line 

 uint8_t buf[25];//you can change this number. it is the number of symbols in transmitter message

2.  Sketches with VirtualWire library:

Transmitter sketch / you will need to modify this line

 const char *msg = "Welcome to Acoptex.com!!!";

Step by Step instruction

1. Do wiring.
2. Setup of tranmitter and receiver can be done on different PC (using installed Arduino IDE softwares) or on the same PC (using installed Arduino IDE and portable Arduino PC softwares) Open Arduino IDE.
3. Plug your Adruino Uno board into your PC and select the correct board and com port
4. Open up serial monitor and set your baud to 9600 baud
5. Verify and upload the the sketch to your Arduino Uno board.
6. Open the Arduino IDE serial monitor to see the values. Transmitter serial monitor window (on the left) and receiver serial monitor window (on the right):

Summary

We have learnt how to connect RF 315/330/433 MHz XD-FST / XD-RF-5V Transmitter / Receiver modules to Arduino board and use them.

Library:

• See attachments on the begining of this project description.
  We have used the library - NewliquidCrystal_1.3.4.zip which we downloaded, unzipped, changed the name of folder to LiquidCristal and added to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC.
  See attachments on the begining of this project description.
• Sketches (transmitter1 and receiver1). We have used the RadioHead library - RadioHead.zip which we downloaded, unzipped and added to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC.
• Sketches (transmitter2 and receiver2). We have used the VirtualWire library - VirtualWire.zip which we downloaded, unzipped and added to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC.

Sketch:

• See attachments on the begining of this project description. 
• Sketches (transmitter1 and receiver1)
• Sketches (transmitter2 and receiver2)