433 ISM tranceiver with rtl_433 decoders

A project log for Fun with wifi repeaters

WiFi repeaters are getting super cheap now ($5!) and can contain quite open hardware. Try to make the most out of the QCA953X based ones.

biemsterbiemster 10/03/2023 at 09:180 Comments

Fun ideas seem to come in quick succession at the moment, after I remember that rtl_433 was ported to the ESP32:

This workaround will be needed since the QCA9533 lacks USB, otherwise rtl-sdr would open up so much more functionality!

I already have an SX1278 in the parts bin so that will be my main target, which will also enable LoRa to be added to the bridge. Actually getting the SX1278 running on the repeater will be the meat of this part of the project, with the 433 decoder a nice use case.

EDIT: It looks like most of the hard work has already been done:

Also RadioLib supports the SX1278 and can run on Linux:

And there is this:

Those three repos above should suffice for getting this to work.

Actually the sx1278 is supported out of the box by the micropython bundled with openwrt!

That will very likely be the way I will approach this, at least for initial testing. One thing left here now is getting SPI to work.

EDIT2: So getting SPI to work was fairly tricky, the cs-gpios in the device tree is not working anymore since the move to the ar934x-spi driver: Setting a CS line now involves pin muxing, which I do not know how to do.

This took me a while to figure out, and I opted to use the older ar7100-spi driver so I can use cs-gpios again, and I chose the WPS led pin to be my CS for spidev0.1. I've uploaded a new firmware to this project with this configuration. (plus setting correct config/network and bpf jit on first boot, so this gets done automatically now!)

This log will be evolving when I continue on this.