433Mhz RF Wireless Transmitter Module and Receiver Kit 5V DC 433MHZ Wireless For Arduino Raspberry Pi /ARM/MCU WL Diy Kit
oday we will examine a low-cost method of sending wireless data between two Arduinos without using wifi or bluetooth. Learn how inexpensive 433MHz modules may be all you need to cut the cord on your next Arduino design.
We are using a frequency of 433MHz in our modules. One wavelength at 433MHz is 69.24 cm. As this is a pretty long antenna (about 27.25 inches) it is more practical to use a half or quarter wave antenna.
Most experimenters use a quarter wave antenna which works out to about 17.3 cm or 6.8 inches.
Hooking up the Transmitter The hookup for the transmitter is very simple, as shown in the following illustration:
The module only has three connection, they are as follows:
VCC – This can be any positive DC voltage from 3 to 12 volts. In this experiment we will get 5 volts from our Arduino.
GND – The ground connection, connected to one of the Arduino ground terminals.
DATA IN – This is connected to pin 12 of the Arduino. You should try and use pin 12 as by default the library we’ll be using in our sketch uses this pin for data output.
You will also want to solder a 17.3 cm piece of solid hookup wire to the antenna terminal on the module.
Once you have the transmitter wired you can move on to the receiver.
Hooking up the Receiver
The receiver is just as easy to hookup as the transmitter was.
Once again there are only three connections to make. Although the receiver module has four pins the two center pins are tied together, so you can use either one for data out.
The connections are as follows:
VCC – Unlike the transmitter this needs to be 5 volts. We will use the 5 volt output from the Arduino.
GND – Again a ground that is connected to any Arduino ground pin.
DATA OUT – This needs to be connected to digital pin 11 on the Arduino.
The antenna connection on the receiver is often unmarked. It is the pad in the lower left of the module, right next to the small coil.
Now that both the transmitter and receiver are wired up we will need to write some code and send it to the respective Arduino boards. Since you probably have only one computer we will start with the transmitter. Once the code has been loaded there we’ll move on to the receiver. The transmitter can then be powered using a power supply or battery.
But before we start coding there is a library we will need to install into our Arduino IDE that will make writing the code a lot simpler.
You will need to download the library from the Airspayce website. Demo Transmitter Code and receiver
Here is the sketch we will be using for our transmitter and receiver: