Alexa skill to control HomeVision Thermostat via ESP8266 without opening a router's port/firewall.
You must have a HomeVision Controller running HomeVisionXL software with the NetIO plug-in and an RCS TX-15B thermostat for this to work.
This project is based on the work of Nassir Malik. See his Youtube tutorials at https://www.youtube.com/channel/UCn8v7OzXk7IqRdKZdf14yjA and code at https://github.com/nassir-malik
TCP code used to talk to the HomeVision system is a modified version from Big Dan the Blogging Man at https://bigdanzblog.wordpress.com/2016/02/09/esp8266arduino-ide-communicating-with-tcp/
In This project you will be able to control a HomeVision Thermostat via ESP8266 with Alexa skills without opening a firewall port or setting up a reverse proxy.
Download this project and unzip.
Copy following folders to "C:\Program Files (x86)\Arduino\libraries"
Update and flash your ESP8266 with "ESP8266/ESP8266_WebSocketClient/ESP8266_WebSocketClient.ino"
Create an Alexa skills using the info in alexa utterences.txt and add Heroku app URL as an end-point
Test and enjoy.
See also this Project's Wiki page for more details.