Do you want to see how to establish a communication link with Arduino? In this Arduino 433MHz RF tutorial we are going to build a simple project just to demonstrate how easy it is to add wireless capability to our Arduino Projects with these 433Mhz modules. I have two Arduinos here. This one is sending the temperature and the humidity it measures every two seconds, and the other one is receiving the data and displaying it on the display. As you can see this one way communication is working fine and the range is good, we can easily get around 6 meters with a small antenna! The theoretical range that we can achieve is more than 100 meters. You can find links for all the parts in the description of the video.
Note: This video tutorial is prepared for Greece, where it’s legal to operate low powered devices (25mW) in the 433MHz band without a license. Check what’s legal in your own country.
These 433Mhz modules is a low cost wireless solution for Arduino. This module is the transmitter and this one is the receiver. We can only establish a one way communication link using these two modules. The cost of both modules is less than 2$! The kit operates at the 433MHz band and it can achieve at a data rate of 4Kbits. The connection to Arduino is extremely easy. We only have to connect the DATA pin of the modules to a digital pin on Arduino. But let’s see how to build this project in detail.
WHERE TO BUY
1. Cheap Arduino Uno: http://bit.ly/Cheap_Uno
2. 433Mhz RF Kit: http://bit.ly/433Rf
3. DHT22: http://bit.ly/DHT_22
4. 1.8″ Color TFT: http://educ8s.tv/part/7735
5. Small Breadboard: http://bit.ly/SmallBreadboard
6. Wires: http://bit.ly/WiresArduino
7. Powerbank: http://bit.ly/PowerBank_XiaoMi
8. Jumper wires: http://bit.ly/JumperWiresB
9. Battery holder: http://bit.ly/4BatteryHolder
First of all, we have to download the VirtualWire library in order to make our life easier when we work with the 433Mhz wireless modules. You can find the link for the library in the description of the video.
Virtual Wire: https://www.pjrc.com/teensy/td_libs_VirtualWire.html
Adafruit GFX: https://github.com/adafruit/Adafruit-GFX-Library
Adafruit ST7735: https://github.com/adafruit/Adafruit-ST7735-Library
Let’s first see the Transmitter code. It sends out a simple data structure which contains two floats, the temperature and the humidity. In order to establish a communication link we have to set which pin we have connected the module to, and set the communication bitrate. In this example I have set the bitrate to 500bps. Next, we read the temperature and the humidity from the sensor, we save the values in the data structure and with this line of code here, we send the data structure. It’s that easy!
Let’s now see the receiver code. Again we declare the same data structure. We initialize the receiver module with the same settings as the transmitter and we wait for data. If there is data available, we save that data in the data structure and then we print that data on the display. It’s that easy! You can find the code of the project in a link in the description of the video.
CODE OF THE PROJECT
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