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Quick Temperature Controller

QuickTempController.jpg

This BrewskiTech project will show you how to create a quick and easy temperature controlled freezer or refrigerator that can be used as a fermentation chamber or a kegerator. The project uses basic electronic components, assembled on a breadboard, to quickly make a fermenter/kegerator that can be controlled and automated via Home Assistant.

Features:

  • Cool fermenting beer or finished beer for serving
  • Built on a breadboard to avoid time-consuming soldering and circuit layout
  • Avoids working with dangerous mains power by using an off-the-shelf device to control AC power to the fridge/freezer
  • View and control temperature though browser or phone based Home Assistant interface
  • Automate temperature ramping and notifications via Home Assistant

All source files are available in the github repo.

Video Tutorial​

A video tutorial is available on the BrewskiTech YouTube channel, which can be found here.

Building the electronics​

The section of the video tutorial on assembling the electronics starts here.

Electronics Plans​

A fritzing file is available for download in the github repo.

Breadboard Plan breadboard

Electronics Materials​

Materials needed:

  • Wemos D1 mini
  • waterproof 1-wire temperature sensor
  • 4.7 k-ohm resistor
  • three position screw terminal block
  • 5V USB power supply (an old cellphone charger will work)
  • Digital Loggers IoT Relay
  • Half-size breadboard
  • Breadboard jumper wire kit

Installation​

The section of the video tutorial on mounting and installing the electronics starts here.

Mounting the components​

The electronic components should be mounted to a secure surface to provide strain relief; basically, we don't want any of the sensitive wires to get pulled out of the breadboard. We used a piece of scrap plywood to act as a base. Then we used screws to secure the breadboard and IoT relay to the board, and a wire hanger to secure the temperature probe cable. Hot glue could also be used to secure the temperature probe cable.

Installing on the freezer / refrigerator​

Rare earth magnets were hot-glued to the back of the base board. The base board will then stick to the metal sides of the chest freezer or refrigerator. We found that the sides of the freezer were slick enough that the base board would slide down, so some double-sided carpet tape was used to create some additional friction between the magnets and the freezer side.

Home Assistant setup​

The section of the video tutorial on configuring the device in Home Assistant starts here.

YAML configuration​

The latest YAML file can be found here.

esphome:
  name: "fermenter2"
  platform: ESP8266
  board: d1_mini

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:
  - platform: esphome
    !secret esphome_ota_password

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Fermenter2 Fallback Hotspot"
    password: !secret wifi_backup_password

captive_portal:

switch:
  - platform: gpio
    name: "Fermenter 2 LED"
    inverted: true
    pin: D4
  - platform: gpio
    id: freezer_power
    name: "Fermenter 2 Freezer Power"
    pin: D5

one_wire:
  - platform: gpio
    pin: D3

sensor:
  - platform: dallas_temp
    name: "Fermenter 2 temperature"
    id: fermenter_temp
    update_interval: 5s

# Fermenter thermostat
climate:
  - name: "Fermenter 2 thermostat"
    id: fermenter_thermostat
    default_preset: home
    platform: thermostat
    visual:
      min_temperature: -1
      max_temperature: 40
      temperature_step: 1
    sensor: fermenter_temp    
    preset:
      # Standard presets
      - name: home
        default_target_temperature_high: 10
    startup_delay: True
    cool_deadband: 0.5
    cool_overrun: 0.5
    min_cooling_off_time: 300s
    min_cooling_run_time: 300s
    min_idle_time: 30s
    cool_action:
      - switch.turn_on: freezer_power
    idle_action:
      - switch.turn_off: freezer_power

Automation​

Since this project is similar in purpose to the Fermenter project, the temperature ramp automation from that project can be used for this device. Please see the section on the temperature ramp automation.