Brew Controller - Specification

The aim for the new brew controller is to control the brew day. This could be built to varying budgets (probably around £200 in what I'm building) primarily determined by the power rating. I am of the view two elements is better than one but haven't actually specified the elements for the boiler yet- the HLT elements are standard kettle elements ~ 11amps each. I'm taking a view that things which can't easily be replaced should aim for 20A - but to keep control on the cost intiially some easily replaced switches are only good for 15A.

In the garage I'm likely to have 1 x 30amp feed and 1 x 13amp feed, two 15A zones is an improvement over the current ATC800+ based temperature controller which is only good for a single 13A zone.


  • 2 x Diverse - Power Zones
  • Control of HLT for heating the mash water, and sparge water. 
  • Control of Boil control
  • Control of fermentation (to replace existing ATC800+), and provide graph of fermentation temperature
  • Automatic control of extractor fan
  • Manual control of 1 Pump
  • Ability to drive the functions from the brew controller, with (perhaps) of remote triggering of functions over a network interface.
  • Base settings for a given receipes should be set from a network interface to avoid manually setting values
  • Ability for real-time status to be seen over the network (web interface, android app) 
  • Allow future expansion to RIMS/HERMS
    • Hardware wise additional pumps may be required and control would move to software

Basic Equipment

  • RaspberryPi for control. 
    • In the previous temperature controller there was stability issues with running two DS18B20 probes. In hindsight this may have been a hardware wiring issue. Since I have a spare RPi two will be used to spread the load. (Testing will determine if refactoring onto a single RPi has any downsides).
  • DS18B20 probes for temperature control
  • HD44780 20x4 LCD screen 
    • previously used a 16x2 which was a little too limiting
  • SSR's for controlling element (1 per zone)
  • Mechanical Relays to protect element sockets 
  • Mechanical Relays to control low-power devices (fridge, heater, extractor fan, pump).
  • Lot's of switches, buttons, wire, sockets and plugs, resistors, transistors
  • MCP23017 I2C switch for providing extra GPIO ports.
  • Old computer case to house it all in.

Parts gathered so far


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