How to create a eWelink supported device ?

[zoufalec]

I use the Sonoff switches to be able to control machines in my small workshop on the distance. For example turning off the compressor in the night when I leave and forget about it :-) Now I have an idea to use inspection USB camera (small and waterproof) as the surveillance cam on the head of one machine. But how to add for example Arduino or Raspberry or other device or other IPcamera to the eWeLink app ?