Fermentation temperature controller

I got an old freezer that was surplus to requirements and a heat pad and then made a control box with an ESP8266 and ESPHome which control a 2 channel relay board.

The microcontroller talks to 3 Maxim/Dallas 1-wire bus temperature sensors, one for the fermenter, one for fridge air and one for the ambient air.

The ESPHome YAML looks like..

esphome:
  name: fermenter
  platform: ESP8266
  board: d1_mini

wifi:
  ssid: "xxx"
  password: "xxx"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Fermenter Fallback Hotspot"
    password: "xxx"

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:

mqtt:
  broker: mqtt.dons.net.au

ota:

dallas:
  update_interval: 30s
  pin: D2

sensor:
  - platform: dallas
    address: 0xFF000801537D4C10
    name: "Fermenter"
    id: fermenter
  - platform: dallas
    address: 0x1600080153406D10
    name: "Fridge"
    id: fridge
  - platform: dallas
    address: 0x8E00080153057610
    name: "Ambient"
    id: ambient

switch:
  - platform: gpio
    name: "Heater"
    id: heater
    interlock: [cooler]
    pin:
      number: D5
      inverted: yes

  - platform: gpio
    name: "Cooler"
    id: cooler
    interlock: [heater]
    pin:
      number: D6
      inverted: yes

climate:
  - platform: bang_bang
    name: "Fermenter Control"
    id: fermenter_control
    sensor: fermenter
    default_target_temperature_low: 18 °C
    default_target_temperature_high: 20 °C
    visual:
      min_temperature: 1 °C
      max_temperature: 30 °C
    visual:
      min_temperature: 1 °C
      max_temperature: 30 °C
      temperature_step: 1 °C

    cool_action:
      - switch.turn_on: cooler
      - switch.turn_off: heater
    heat_action:
      - switch.turn_on: heater
      - switch.turn_off: cooler
    idle_action:
      - switch.turn_off: heater
      - switch.turn_off: cooler

A shot of the internals:

There's a lot more space after replacing the previous Atmel version.

-- Main.darius - 30 Sep 2007