Just my shiny new µArt ( https://www.crowdsupply.com/pylo/muart) to flash some custom firmware on a couple of cheap Sonoff wifi switches ( https://www.banggood.com/DIY-Wi-Fi-Wireless-Switch-For-Smart-Home-With-ABS-Shell-p-1019971.html). They now work with Alexa without some dodgy third party cloud service.

It’s funny that the USB UART I used cost considerably more than the devices!

A small circuit board taped to a bench. On the left are two crocodile clips attached to two small wires which go under the board. These provide external power. Coming out of the centre of the board is a ribbon cable. This goes to the UART. The board is rectangular with a relay on the bottom right corner and small screw terminals at each end.

Of course these switches don’t have any sort of earth passthrough, so I guess I’ll need to add something if I want to use them with almost anything useful.

Also, the firmware I used was Tasmota ( https://github.com/arendst/Sonoff-Tasmota/) which supports other cool things like MQTT as well as Belkin emulation.