Overview

This is my custom controller for my keezer. I am building this from the ground up because I have some very specific ideas that I want to include and I have found no other solution (custom or off the self) that meets my needs.

Build status

Master Branch Dev Branch

Goals

I have a number of goals I want to achieve for this custom controller. At this point I doubt all of this could or should be done on a single ESP8266 micro. It is likely I will have a number of ESP8266's that work together over MQTT to achieve all of the functionality I want. This project will evolve over a long period of time.

Future list of features

Check out the Github Issues (label enhancements) for a list of features that are planned for a later date.

Features

This is a list of actual features the current code base supports.

Current list of features

Measure the temperature inside the keezer with two temperature sensors (one at the top and one at the bottom).
Measure the temperature outside the keezer.
Control the keezer temperature given a temperature set point and the temperature sensor reading ().
Display the current temperature of the keezer on an LCD.
Turn on/off a fan(s) to circulate the air in the keezer when the difference between the top and bottom sensors is greater than a given threshold.
Detect motion when someone approaches the keezer.
Turn on LED lighting and LCD display when someone approaches and turn off the lighting and LCD display after a delay.
Connects to MQTT broker using a user name and password.
Broadcast over MQTT sensor readings such as: temperature and motion.
Broadcast over MQTT event changes such as: compressor, fan and lights turning on/off.
Respond to an MQTT ping request so that an external application can determine what keezers are online.
Allow the keezer to join a wifi network without changing the code
Allow for the keezer to join a new Wifi or a different MQTT broker by holding down the mode pushbutton for > 3 seconds.
The keezer continues to maintain the temperature of the beer even if the Wifi is down or the MQTT broker is down. The highest priority is to keep the beer nice and cold.

Hardware

Wiring

I used Fritzing to document the wiring of all components. After installing Fritzing just open the doc\keezer.fzz file from Fritzing. Or you can look at the doc\Wiring.png file.

I/O

1 gpio for 1 wire for temperature sensors
1 gpio for relay dc fan
1 gpio for relay LED light strip
1 gpio for relay compressor
1 gpio for motion sensor
2 gpio for LCD
1 gpio for push button LCD mode

LCD Display layout

A push button allows you to change the mode of the LCD. Mode 1 is the default mode and after a certain amount of time the LCD will fall back into this mode.

Example Mode 1 Top, Average & Bottom Compressor on

Current Temperature
Set  43.0 Top 44.5
          Avg 43.5
Comp On   Bot 42.5

Example Mode 1 Top, Average & Bottom Compressor off

Current Temperature
Set  43.0 Top 44.5
          Avg 43.5
Comp Off  Bot 42.5

Example Mode 2 External Temperature

Current Temperature
          Ext 82.0
        
Comp Off

Example Mode 3 Set Temperature

Set Temperature
High          44.0
Avg           43.0
Low           42.0

Dependencies

This application depends on the following libraries:

OneWire
DallasTemperature
RBD_Timer
RBD_Button
Adafruit LiquidCrystal
PubSubClient
WifiManager
ArduinoJson

Build

There are a couple things you need to do so that you can compile the project. I converted this project to use Platform IO so you will need to install it as well as an editor. I personally think that the Visual Studio code editor works very well with Platform IO.

Make a copy of the myconfig.sample.h and rename it myconfig.h
Edit the myconfig.h and set the specific topics that you want the keezer to use (or leave them as is). If you have more than 1 keezer make sure you changed the integer in all the topics so that one keezer can be addressed differently than the other keezer
You can also make changes to the default settings in myconfig.h
TODO Detail how someone sets the right index values for the temperature sensors since they are different for every sensor.
Place the ESP8266 into flash mode
Run the following command pio run --target upload
The first time that the application is downloaded to the target platform it will put the device in an Access Point mode which will allow you to configure it for connection to your Wifi
Open your Wifi and connect to "mykeezer-ap". Note you have 120 seconds after power on to complete this task before the keezer falls out of AP mode and starts controlling the temperature of the beer. If you dont complete this process before the 120 second timeout simply cycle the power on the keezer and try again
Click on the Wifi setup button and fill in the text fields. Once the information is submitted the device will connect to Wifi and the MQTT broker
If you need to change the MQTT or Wifi settings just hold in the mode button for longer than 4 seconds and the device will become an Access Point again for configuration.

MQTT

The only way to communicate with the keezer is to use MQTT messages. Currently the integration is mostly one way (keezer publishing messages to MQTT), but at some point you will be able to control aspects of the keezer by sending messages to it. If you have never used MQTT before then I would advise you to head on over to MQTT.org to learn more about it.

Note: This is a work in progress and I am likely going to re-factor these MQTT topics and message formats as I evolve the application over time.

Topics and Messages

The Topics and Messages that the keezer uses will be defined here so that you have one place for determining how to interact with it. You can also edit the mymqttbroker.h file to customize how you want your topics to be defined on the MQTT bus. For instance not everyone will want their MQTT topics to start with /home/keezer like I have put together. Hopefully this meets everyones needs on allowing the keezer to exist along with any other MQTT topics you have on your network.

MQTT Subscriptions

The following subscriptions are supported by the keezer.

Keezer ping

This allows some external application to request what keezers are on the bus. Each keezer (if you have multiple) will respond to this ping request.

/home/keezer/ping

MQTT Publications

Keezer ping response

In response to the ping request each keezer will publish the following. Where {id} is the unique id (integer) of the keezer. This allows for more than one keezer to exist on the bus.

/home/keezer/pingr/{id}

Keezer temperatures

The keezer will broadcast the current temperature readings. Where {id} is the unique id (integer) of the keezer. The body of the message contains a floating point number that represents Fahrenheit. There are multiple temperature readings that the keezer tracks: Average, Top and Bottom.

/home/keezer/{id}/temp/avg {float}
/home/keezer/{id}/temp/top {float}
/home/keezer/{id}/temp/bottom {float}

Keezer motion detection

The keezer will broadcast the status of the motion detector when it changes. Where {id} is the unique id (integer) of the keezer. The body of the message contains a 1 or 0 indicating if there was motion detected (1) or motion has stopped being detected (0).

/home/keezer/{id}/motion/value 1
/home/keezer/{id}/motion/value 0

Keezer compressor status

The keezer will broadcast when the compressor is turned on/off. Where {id} is the unique id (integer) of the keezer. The body of the message contains a 1 or 0 indicating if the compressor was turned on (1) or off (0).

/home/keezer/{id}/compressor/value 1
/home/keezer/{id}/compressor/value 0

Keezer fan status

The keezer will broadcast when the fan(s) is turned on/off. Where {id} is the unique id (integer) of the keezer. The body of the message contains a 1 or 0 indicating if the fan was turned on (1) or off (0).

/home/keezer/{id}/fan/value 1
/home/keezer/{id}/fan/value 0

Keezer light status

The keezer will broadcast when the light is turned on/off. Where {id} is the unique id (integer) of the keezer. The body of the message contains a 1 or 0 indicating if the light was turned on (1) or off (0).

/home/keezer/{id}/light/value 1
/home/keezer/{id}/light/value 0

mlinnen/my-keezer