i have completed a project which may be useful to other people
the sonoff sensor range for the th10 / th16 this very restricted
(temperature and humidity)
the project involves interfacing ANY sensor to the sonoff th10 / th16 by spoofing the 1 wire protocol
i have searched the web and i do not think anyone has done this
it was quite tricky and only one 1 wire library worked for me so all credit to the author
i have used a lux sensor for my project
the main benefit is you can still use ewelink
i have had the project running for over a year using a lux sensor for switching the back garden lights on and off accurately with a light level
you have to live with the temperature range settings in the sonoff but you can easily scale in the code to suite