Heating Brain

Heating Brain is a hobby project and kind of a playground. It means the code may change a lot, and there are several places for improvements.

I've started the project because I was very disappointed about "the industry device" for controlling the floor heating system in my house. It turned out that it is highly inefficient and lacks features that I would like to have. I decided to buy a Raspberry PI Zero, a Relay controller, a few 1-wire sensors and put it together. I created this application to:

• allow checking the temperatures, valves state, and gas stove via UI (i.e., heating-brain.local),
• ensure the controller won't enable gas stove until there is a sufficient heating extraction (i.e., enough floor sections are opened),
• allow introducing a complex "expected temperates time-table" for all sections.

In the future, I would like to improve the system by teaching it when to start the gas stove to achieve the expected temperature on a given hour in a given section (handling the thermal inertia of the floor).

The controller already gave my 20-30% better performance than "the industry device" in terms of gas consumption.

Requirements

See .tool-versions file.

Deployment

./server/deploy

Raspberry Pi Zero Setup

On the memory card

1. Install Raspbian Buster Lite on the memory card. See official documentation for details.

2. Copy server/config.txt into the card (as config.txt).

3. Configure network connection by creating wpa_supplicant.conf file on the card with the following content (adjust the credentials):

   country=PL
   ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
   update_config=1
   network={
       ssid="[wifi-name]"
       psk="[wifi-password]"
       key_mgmt=WPA-PSK
   }
   

4. Enable SSH by creating ssh file.

From host system after booting the server:

1. Allow password-less SSH connections:

   ssh-copy-id pi@[ip]
   

On the server

1. Set the hostname:

   sudo sed -i 's/raspberrypi/heating-brain/g' /etc/hostname
   sudo sed -i 's/raspberrypi/heating-brain/g' /etc/hosts
   

2. Fix the cannot change locale (en_US.UTF-8) issue:

   sudo sed -i 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/g' /etc/locale.gen
   sudo locale-gen en_US.UTF-8
   sudo update-locale en_US.UTF-8
   

3. Set the new password:

   sudo passwd pi
   

4. Upgrade distro:

   sudo apt-get update
   sudo apt-get dist-upgrade
   sudo apt-get autoclean
   

5. Install Erlang and Elixir.

6. Configure rsyslog (optional):

   # /etc/rsyslog.d/01-ignore-rngd.conf
   if $programname == 'rngd' then /var/log/rngd.log
   & stop
   
   if $programname == 'rng-tools' then /var/log/rngd.log
   & stop
   
   # /etc/rsyslog.d/02-cron.conf
   if $programname == 'cron' then /var/log/cron.log
   & stop
   
   # /etc/rsyslog.d/99-nas.conf
   use local address like "rsyslog.local"
   *.* @192.168.2.10:514
   
   $ActionQueueFileName queue
   $ActionQueueMaxDiskSpace 1g
   $ActionQueueSaveOnShutdown on
   $ActionQueueType LinkedList
   $ActionResumeRetryCount -1
   
   # /etc/logrotate.d/rsyslog
   /var/log/rngd.log
   {
     rotate 4
     weekly
     missingok
     notifempty
     compress
     delaycompress
     sharedscripts
     postrotate
       /usr/lib/rsyslog/rsyslog-rotate
     endscript
   

7. Create application directories:

   mkdir -p /srv/backups /opt/heating_brain
   chown pi:pi /opt/heating_brain/ /srv/backups/
   

8. Configure backups:

   # Add in crontab:
   
   0 * * * * /opt/heating_brain/_build/prod/rel/heating_brain/bin/heating_brain rpc ':ok = Collector.Storage.create_backup()'
   15 10 * * * find /srv/backups -type f -mtime +14 -ls -exec rm -f -- {} \;
   

From host system after setting up the server:

1. Deploy the code:

   ./server/deploy
   

   The first deployment will be significantly longer.

Resources

• (Mnesia manual)[http://erlang.org/doc/man/mnesia.html]
• (Raspberry Pi Pinout)[https://pinout.xyz/]
• (Installing OS on the memory card)[https://www.raspberrypi.org/documentation/installation/installing-images/README.md]