This project uses Arduino Pro Mini (Atmega328P) board. However, all sources are provided in AVR native C.

The goal is to provide accurate fermentation chamber temperature control (within 0.1 degree celsius). Similar to brew pi, the complete system contains AVR microcontroller board running control algorithm. The SW on board implements serial terminal for controller configuration and state reading, but the ultimate goal is to create stand alone controller configurable via digital input elements (push button + incremental encoder) while state reading will be possible via i2c lcd screen.

Although sharing similar system architecture to brew pi, this project is completely independent and created from scratch.

Until all hardware elements are in place, Atmega will be controlled with raspberry pi via serial interface

• web_server - Contains sources for web server and services running on it
• rpi - Contains sources of the raspberry pi
• src - Contains sources for the AVR

Board documentation can be found here.

Here is also direct link to pdf schematics.

Installing SW on web server goes down to:

• installing web page
• installing handler for messages

To install web page, copy server_software/web_server contents into /var/www/html/beer to your favourite server.

To install handler for messages, copy server_software/apps/beermon_handler.py to server and try to run it.

It is possible you'll need some additional SW. To install necessary SW, execute (at least):

sudo apt-get update
sudo apt-get install python python3 mosquitto mosquitto-clients python-mosquitto python3-pip python-pip -y
sudo pip3 install paho-mqtt
sudo pip2 install paho-mqtt

After this, make sure your firewall is configured to receive on 1883

Once beermon_handler.py works, you can proceed with service installation. Copy beermon.service:

sudo cp beermon.service /etc/systemd/system/
sudo systemctl enable beermon.service
sudo systemctl start beermon

RPi part is installed by executing rpi/beermon-rpi.py on rpi startup. For detailed instructions, check instructions within rpi sw directory.

These instruction assume that either USBasp or buspirate AVR programmer with avrdude are used for device programming.

Install following tools

• avr toolchain
• gnu make
• avrdude

and configure your PATH variable.

Here will be given Linux instructions.

Install required packages:

sudo apt-get install avr-libc avrdude binutils-avr gcc-avr srecord

Clone the repo, build the sources with make, and push hex file to board with following command.

$ avrdude -c usbasp -p m328p -u -U flash:w:beer_tc.hex

Before any operations, learn port of the buspirate and set it:

port=/dev/ttyUSB0

To program device, execute:

sudo avrdude -c buspirate -P $port -p m328p -u -U flash:w:bin/beer_tc.hex

To power atmega from buspirate, execute:

echo "m 2 " > $port;echo "W" > $port

When beer_tc is running on AVR board, the following commands can be issued via serial interface. all commands are terminated with new line character.

Get commands come in following form

    get <object>

and the response is formated requested object type. The list of retrievable objects as well as belonging types are given in following table.

Format for requesting is "get \n", where response does not contain any newline characters.

Set commands come in following form.

    set <object> <value>

If execution is successful, command returns ok. If not the command fail reason string is returned.

While get command is supported for all listed objects, only some can be updated with set command.