Sour Dough Climatizer Project

PID temperature controller powered by ESPHome and controlled by Home Assistant

We love to produce our own bread - and when I say ‘we’, I mainly mean my wife, who is the one doing the magic here. We honed in on sour dough bread in particular. It is a living dough that one can maintain and pamper for a long period of time by feeding, splitting (for using parts in a bread) and then repeating the cycle.

The quality went down recently and we were wondering why.. Main suspicion was temperature and fluctuations of it (culprit may be winter time).

So, I went onto a journey to create a climatizer to keep our dough happy.
The accompanying video you’ll find on Youtube:

Schematics

The schematics aren’t really complicated:

Bill of materials

• a ESP8266

  • like ESP-12 WeMos D1 Mini, I used this one

• USB-C Power Board

  • I used one similar to this one

• Heater Foil

  • 5V 2.5W Foil

• Mosfet IRLZ44N

  • Infineon datasheet

• Temperature Sensor DHT22

ESPHome Program

Final program, which’s result I analyze in the end of the video:

climate:
  - platform: pid
    id: "sauertiger_pid"
    name: "Sauertiger PID"
    internal: no
    sensor: sauertiger_temp
    default_target_temperature: 26°C
    heat_output: sauertiger_pwm
    control_parameters:
      kp: 3.0
      ki: 0.00049
      kd: 12.56301
      output_averaging_samples: 2      # smooth the output over 5 samples
      derivative_averaging_samples: 2  # smooth the derivative value over 10 samples
    deadband_parameters:
      threshold_high: 0.2°C
      threshold_low: -0.2°C

sensor:
  - platform: dht
    id: sauertiger_sensor
    pin: D2
    model: DHT22
    temperature:
      name: "Sauertiger Temperature"
      id: "sauertiger_temp"
    humidity:
      name: "Sauertiger Humidity"
      id: "sauertiger_humid"
    update_interval: 5s

output:
  - platform: esp8266_pwm
    pin: D3
    frequency: 10 Hz
    id: sauertiger_pwm

number:
  - platform: template
    name: Sauertiger Target Temperature
    id: sauertiger_target_temp
    min_value: 10
    max_value: 40
    step: 1
    optimistic: True
    set_action:
      then:
        - climate.control:
            id: sauertiger_pid
            mode: auto
            target_temperature: !lambda 'return x;'

3D Models

There is still a small issue with the model I wanted to fix. But before I do that I’ll wait for my Prusa Core One delivery ;-)

If you (for some reason) want to have the model before that time, let me know..

Result

I am very pleased with the result and its ability to maintain a certain temperature. And it definitely helped already boosting some dough production ;-)

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