Achieved target: 1. Voice control of indoor fan, heating, cooling on/off. --------------------------------------------------------------------------- Materials: 0. Original thermostat: Honeywell CT87N4450 (shown in the figure on the right) Terminals (shown in the figure on the right; after removal of the mechanical controller): G (green wire): Indoor fan (air circulation) W (white wire): Heating (gas furnace) Y (blue wire): Cooling (AC) R and Rc connected (red wire): Power Jump connect G,W,Y with power to turn on the fan, heating and cooling. Voltage between each of G,W,Y and R/Rc is measured to be approximately 28~29V (AC). 1. NodeMCU-V3-Lua-WIFI-Module-ESP8266-32M-Extra-Memory-Flash-USB-Serial-CH340G A firmware based on ESP8266 wifi-soc. Can be programmed on Arduino IDE. 2. 4-channel relay 3. Cell phone battery (3.8V output) 4. Google Home Mini for voice control | Useful resources: 1. Building an open source Nest https://blog.particle.io/2014/01/17/open-source-thermostat/?redirected=tru Costs: 1. NodeMCU: USD 5.96 2. Google Home Mini: USD 40 |
honeywell_ct87n.pdf |