Caecilius wrote:
Thanks for that link - I much prefer something like this that uses a
standard protocol like ZigBee then a proprietary RF protocol as one
day I might want to add additional sensors or integrate the
temperature readings into a central heating control system.

Agreed. If you look at the list of devices supported by zigbee2mqtt:
https://www.zigbee2mqtt.io/informati...d_devices.html

it's actually quite comprehensive - lots of sensor/actuator options.
Includes the usual suspects like Hue, Hive, Ikea, etc.
And some of the Chinese stuff is quite cheap.

(Now, if somebody did some affordable UK wall sockets with measurement,
that would be very handy...)

Theo