I've created a small project using the ESP-01 board where I'm using the native MQTT client and a DS1631 temperature sensing IC. The temperature is displayed on Openhab. At the moment, I only have a single temperature sensing board, but soon I hope to have on in each room and then expend the project to control the thermostat as well.
I've got a blog entry at https://mydiyelectronics.wordpress.com/ ... e-monitor/
I've also created a github project, which is still in it's infancy (first time I've used github...) if anyone's interested. https://github.com/nerobot/ESP8266-Thermostat
Thanks again for the great work being done on this forum.
Steven