Brewberry π 
Given a DS18B20 temperature sensor, a solid state relays and a wifi connector, automate the mash process.
At least, that's the plan.
This repo contains the code of my brewberry-π home brew software, built with Elixir and Nerves.
Brewberry π can:
- control temperature within a 0.1 °C margin
- read, set and control the mash process with your phone (web ui)
- brewing software can be upgraded over the network
- it's firmware, so you can pull out the plug at any time
Why Elixir/Nerves? Well...
- Elixir is build on Erlang technology, making it fault tolerant by design.
- Nerves provides a basis for real firmware. You can just pull out the power plug without bad things happening (you do not want to try that with Rasbian).
- The system is up and running in less than 6 seconds(!) (not including wifi authentication). This is a lot faster than the 60 seconds it takes for Rasbian to boot.
- The Erlang/Elixir actor model is a natural fit for message driven applications.
An older version of the Brewberry-π written in Python is available at https://github.com/amolenaar/brewberry-pi-python.
Get started
- Go to the web application with
cd apps/web - Run
mix deps.get MIX_ENV=dev iex -S mixwill lauch the app and open a console, so you can tinker around- Open a browser on http://localhost:3030, the (web) app will be running there in "fake" mode
Firmware
To build an image for the Raspberry Pi (model B):
- Ensure Nerves stuff is installed on your machine, check out the Nerves getting started guide
- Go to the firmware application with
cd apps/fw_rpi - Install dependencies with
MIX_ENV=prod mix deps.get - Copy
apps/fw_rpi/config/wifi-example.exs.exampletoapps/fw_rpi/config/wifi.exsand fix the ssid and psk properties - Create firmware with
MIX_ENV=prod mix firmware - Burn to an SD card with
MIX_ENV=prod mix firmware.burn - And do remote updates once your first image is up and running:
MIX_ENV=prod mix firmware.push 10.192.168.122 --firmware ../../_build/rpi/prod/nerves/images/fw_rpi.fw
PCB
To control a brewing kettle some additional hardware is required:
- http://learn.adafruit.com/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing
- http://en.wikipedia.org/wiki/Solid-state\_relay
A schema is made with Fritzing and is available in the file Brouwerij.fzz.
Bill of Materials
| Label | Part Type | Properties |
|---|---|---|
| - | - | PCB prototype board |
| J1 | Screw terminal | 3 pins, connector to DS18B20 |
| J2 | Power plug | connector to SSR |
| Pi1 | Adafruit Pi Cobbler | manufacturer Adafruit Industries |
| Q1 | NPN-Transistor | type NPN (EBC); package TO92 [THT] |
| R1 | 4.7kΩ Resistor | pullup resistor |
| R2 | 1kΩ Resistor |
Learn more
- Elixir: http://elixir-lang.com
- Nerves docs: https://hexdocs.pm/nerves/getting-started.html
- Nerves website: http://www.nerves-project.org/
TODO
- Use bootloader from https://github.com/mobileoverlord/bootloader