BrewBlox Service for the Tilt Hydrometer
The Tilt hydrometer is a wireless hydrometer and thermometer used to gather live readings of specific gravity and temperature when brewing beer.
BrewBlox is a modular brewery control system design to work with the BrewPi controller.
This brewBlox service integrates the Tilt hydrometer into BrewBlox.
Bluez is Linux's bluetooth software stack. The version provided by Raspbian by default can be unstable. It's recommended you update it from the Debian repositories with the following command:-
wget http://http.us.debian.org/debian/pool/main/b/bluez/bluez_5.50-1_armhf.deb && sudo dpkg -i bluez_5.50-1_armhf.deb && rm bluez_5.50-1_armhf.deb
Deploy the Tilt service on the BrewBlox stack
You need to add the service to your existing BrewBlox docker compose file.
tilt: image: j616s/brewblox-tilt:rpi-latest restart: unless-stopped privileged: true depends_on: - history network_mode: host command: -p 5001 --eventbus-host=172.17.0.1 volumes: - ./tilt:/share
The brewblox-tilt docker images are available on docker hub.
Note that the image tag to use is:
- rpi-latest for the arm architecture (when deploying on a RaspberryPi)
- latest for the amd architecture
You'll also need to modify the eventbus entry in your existing BrewBlox docker compose file to look like this.
eventbus: image: arm32v6/rabbitmq:alpine restart: unless-stopped ports: - "5672:5672"
Finally, you'll have to bring up the new service using
Add to your graphs
Once the Tilt service receives data from your Tilt(s), it should be available as graph metrics in BrewBlox.
Calibration is optional. While the Tilt provides a good indication of fermentation progress without calibration, it's values can be less accurate than a traditional hydrometer. With calibration its accuracy is approximately that of a traditional hydrometer. If you wish to use your Tilt for anything beyond simple tracking of fermentation progress (e.g. stepping temperatures at a given SG value) it is recommended you calibrate your Tilt.
To calibrate your Tilt, you first need to create a folder for the calibration files to be stored in. The recommended folder is
./tilt in the BrewBlox directory. You can use other directories but you should change the volume parameter for the Tilt service in your docker compose file accordingly. You can create the
tilt directory by running the following command in the BrewBlox directory:-
NOTE: It is recommended you create the
tilt folder before launching the Tilt service for the first time. Failure to do so will result in the docker service creating the folder as root. If this happens, use
chown to change the user and group ownership of the
tilt folder to match the rest of the BrewBlox directory.
If you wish to calibrate your Specific Gravity readings, create a file called
SGCal.csv in the
tilt directory with lines of the form:-
<colour>, <uncalibrated_value>, <calibrated_value>
The uncalibrated values are the raw values from the Tilt. The calibrated values are those from a known good hydrometer or calculated when creating your calibration solution. Calibration solutions can be made by adding sugar/DME to water a little at a time to increase the SG of the solution. You can take readings using a hydrometer and the Tilt app as you go. You can include calibration values for multiple colours of Tilt in the calibration file. A typical calibration file would look something like this:-
black, 1.000, 1.001 black, 1.001, 1.002 black, 1.002, 1.003 black, 1.003, 1.004 red, 1.000, 1.010 red, 1.001, 1.011 red, 1.002, 1.012 red, 1.003, 1.013 red, 1.004, 1.014
You will need multiple calibration points. We recommend at least 6 distributed evenly across your typical gravity range for each Tilt. For example, if you usually brew with a starting gravity of 1.050, you may choose to calibrate at the values 1.000, 1.010, 1.020, 1.030, 1.040, 1.050, and 1.060. The more calibration points you have, the more accurate the calibrated values the service creates will be. Strange calibrated values from the service are an indication you have used too few or poorly distributed calibration values.
Calibration values for temperature are placed in a file called
tempCal.csv in the
tilt directory and have the same structure. Temperature values in the calibration file MUST be in Fahrenheit. The tempCal file can also contain calibration values for multiple Tilts. Again, it should contain at least 6 points distributed evenly across your typical range. A typical tempCal file would look like this:-
black,39,40 black,46,48 black,54,55 black,60,62 black,68,70 black,75,76
Calibrated values will be logged in BrewBlox separately to uncalibrated values. If you don't provide calibration values for a given colour of Tilt, only uncalibrated values will be logged. You don't need to calibrate both temperature and SG. If you only want to provide calibration values for SG, that works fine. Calibrated temp values would not be generated in this case but calibrate SG values would.
It is also recommended that you re-calibrate SG whenever you change your battery. Different batteries and different placements of the sled inside the Tilt can affect the calibration.
As the Tilt does not talk directly to the BrewPi controller, you cannot use your Tilt to control the temperature of your system. This service currently only allows you to log values from the Tilt. To control your BrewPi/BrewBlox setup you will need a BrewPi temperature sensor.
You can build a docker container for x86 using the following:
Or for ARM using the following:
bbt-localbuild --arch arm
You can then run this container using the following:
docker run --net=host --privileged -v ~/brewblox/tilt:/share j616s/brewblox-tilt:local