ESP8266 (NodeMCU) controlled beer fermentation chamber.
The whole project is created by modifying a wine cooler, similar to this one without the digital temperature controls or LCD.
The microcontroller is an ESP8266 board v0.9.
The ESP8266 controls a two channel relay module.
One of the relays control the peltier cooler.
The other relay controls the fans for the heatsinks that are connected to the peltier cooler. The temperature readings are provided by a DS18B20 temperature probe. You'll also need a 4k pullup resistor between the data and the power lines.
The power supply, heatsinks and fans are reused from the wine cooler itself.
- D0 - controls the relay of the cooling fans (high - fan on)
- D1 - controls the relay for the peltier (high - power on)
- D4 - the data pin for the DS18B20
Use ESP8266Flasher to upload the firmware in the repository. If you want to build your own, use http://nodemcu-build.com/, use the dev branch and enable the following modules: file,gpio,http,mdns,net,node,ow,sntp,tmr,uart,wifi
Use ESPLorer for uploading the files.
You will need an additional "credentials.lua" file with contents like this:
wifi_ssid = "MyWifi"
wifi_password = "MyPassword"
thingspeak_api_key = 'MYTHINGSPEAKAPIKEY'
thingspeak_channel_id = 123456Every 30 seconds, it takes a temp reading. It enables/disables the cooling based on the temperature, then submits the temperature data to thingspeak (check out my channel here).
It also runs a HTTP server for setting the target temperature.
- if the wifi goes away, the main loop stops (?)
- don't lose thingspeak data if there is no wifi
- enable heating by reversing the peltier polarity
- make it possible to update the wifi ssid/password from the http control site