Setting up fermentation control with a Blynk user interface

Overview

Many strains of yeast benefit from fermentation at a lower than indoors ambient temperature. For lagers, fermenting at a low temperature is required.

Here we describe how TFBrew can be used to control a fridge used as a fermentation chamber. We describe what hardware is needed, how to configure TFBrew and how to set up a Blynk user interface.

Hardware needed

• Fridge you can fit your fermenter into.
• Raspberry Pi to run the software (version 3 or Zero W if you want to monitor the changes in gravity with a Tilt Hydrometer)
• A DS18b20 one-wire temperature probe to measure the fermentation temperature
• To turn the fridge on and off, either of:
  • A WiFi controlled TPLink socket such as HS-100 or HS-110. This is the easy option, no wiring required.
  • A relay (preferably Solid State Relay that you can connect directly to a GPIO output on the Raspberry Pi).

Optional hardware

• Tilt Hydrometer to measure gravity as the fermentation progresses
• A second DS18b20 one-wire temperature probe to measure ambient temperature

Hardware setup

Configuration

sensors:
  - FridgeTemp:
      plugin: W1Sensor
      id: 10-000123456
      offset: 0.0
# AmbientTemp is optional
  - AmbientTemp:
      plugin: W1Sensor
      id: 10-000803628fd8
      offset: 0.0
# Tilt is optional
  - Tilt:
      plugin: TiltSensor

actors:
# If using the TPLink wifi socket, use the second compressor setup
  - Compressor:
      plugin: GPIOActor
      ip: 192.168.1.65
#  - Compressor:
#      plugin: TPLinkActor
#      ip: 192.168.1.65

controllers:
  - FermentationFridge:
      plugin: HysteresisLogic
      logicCoeffs:
        allowedOvershoot: 0.1
        allowedUndershoot: 0.0
      actor:  Compressor
      sensor: FridgeTemp
      initialSetpoint: 23
      initialState: on

extensions:
  - blynk:
      plugin: BlynkLib
      server: blynk-cloud.com
      port: 8442
      token: 123456645459866e233984d00sdf

connections:
  - FridgeTemp.temperature=>blynk.v9
  - AmbientTemp.temperature=>blynk.v10
  - Compressor.power=>blynk.v2
  - Tilt.temperature=>blynk.v3
  - Tilt.gravity=>blynk.v5
  - Tilt.temperature=>web.tilt_temp
  - Tilt.gravity=>web.tilt_gravity
  - FridgeTemp.temperature=>web.fridge_temp
  - AmbientTemp.temperature=>web.ambient_temp
  - Compressor.power=>web.compressor_power
  - blynk.v6=>FermentationFridge.setpoint
  - blynk.v7=>FermentationFridge.undershoot
  - blynk.v8=>FermentationFridge.overshoot
  - FermentationFridge.setpoint=>web.setpoint

Setting up a Blynk user interface

You can clone my user interface by installing the Blynk app on your phone/tablet and then visiting this link [http://tinyurl.com/yadlr6zo]