I know this has gone around a few times so I wanted to put in an official request for adding support for Particle’s line of devices. The Photon and Electron being their most popular but also, if possible, their new line of mesh products. I know their was an unsupported work-around library based on Blynk but since now having to use MQTT the Particle boards will no longer work.
Hope to see support and integration for these in the future. Keep up the great work! 
There’s nothing stopping us from using a standard MQTT library to connect the device. You can see my struggles here. I’m able to get a Particle to connect to a local MQTT server but I have not turned on authentication yet. If I had to guess, it doesn’t connect to Cayenne because the username/password is longer that the max specs of MQTT and the MQTT library is truncating it which obviously would fail authentication. I’ll work with it over the next few days to see what I can accomplish.