Main Content

Let's turn lights on with the computer the 433Mhz way

A while ago I started using home assistant on a pi and bought some inexpensive 433Mhz ac wireless switches. However, after one month of intense use the Raspberry Pi didn’t have enough power, so I bought a cheap computer of eBay for this purpose and it worked well expect that I didn’t have control over my switches. Sure I could have use the raspberry in conjunction with the computer but that would be overkill, so I started designing an Arduino on a stick with USB and 433Mhz tx and rx. The first design I made was way too optimistic I planed to use a rf switch to switch between rx and tx and use a single sma port for the antenna but that didn’t go so well and neither tx nor rx was working, so I just gave up for a few weeks and then made version two.

Version two is smaller and have two coiled antennas instead of a sma port and it works well enough. It’s still based around an atmega328 running at 16MHz with the Arduino UNO bootloader and a CH340 USB to Serial converter. As it’s so versatile in its operation, I also added expansion port for SDA / SCL / A0 / Pin8 (PD0) in addition to the iscp header with the spi bus so that the board could be used as standalone transmitter to send sensor values for example.”

Link to article