WiFi chips are incredibly cheap these days, and pretty much every computer has them built in. So, it’s easy to default to WiFi anytime you need devices to communicate with each other. You could have two computers sitting a foot apart, and it’s easier to communicate through WiFi than pretty much any other method. But, that doesn’t mean it’s always ideal — particularly when WiFi isn’t available. This MagPi Magazine tutorial will teach you how to use 433MHz radio for communication instead.
This tutorial is mostly a learning exercise, but the underlying concepts could be very useful. You can use 433MHz radio to control a lot of traditional home automation devices, like wireless electrical sockets. Or, you can let Raspberry Pi projects talk to each other when they are away from WiFi. To get started you’ll need two Raspberry Pis, two 433MHz radio transceiver module kits, two breadboards, and some M/F jumper wires.
The transceiver kits come with two boards: one for transmitting radio, and one for receiving. Those are connected to the Raspberry Pis’ GPIO pins so you can use any Raspberry Pi model, including the the Zero. To communicate between the boards, you will use the simple RF Chat Python 3 program. Sending messages is as easy as typing them in the terminal. From there, you can move on and control 433MHz remote-control electrical sockets. Just receive the original remote’s code and write it down or remember it, then send it back to control the socket!