Time and temperature are two important parameters that are monitored during the brewing process. I developed a device that times the various brewing steps and where applicable monitors the temperature.
Here is a list of the available functions:
- Brew – Starts a timer showing time for the overall brewing process. It also displays the current battery voltage and display a warning if the voltage is getting low.
- Strike – Displays the temperature as the strike water is heated. It also displays the temperature rate of change so the end time can be predicted.
- Mash – Tracks the time and temperature during the mashing process. A warning will be displayed and an alarm sounded if the temperature falls outside the minimum and maximum allowed range.
- Sparge – Similar to the mashing function.
- Boil – Tracks the time during the boiling process. An alarm is sounded for each of the hop additions.
- Chill – Monitors the wort temperature as it is cooled and sounds an alarm when it reaches the desired temperature.
- Alarm Toggle – This will enable or disable the alarm sound.
- Display Backlight – This will turn on or turn off the display backlight.
- Defaults – These are the tunable parameters such as minimum temperature and maximum temperature, mash, sparge and boil times, etc.
I used the Pololu SVP-324 for the hardware platform. The SVP makes a good general purpose project platform. The SVP has all of the needed hardware for this project except the temperature probe.
Here is a list of the hardware functions I used. There are many more features available such as motor controllers, multiple digital inputs and outputs, servo control lines and two regulated power supplies one of which is adjustable.
- ATmega324PA AVR microcontroller (32 KB flash,2 KB RAM, 1 KB EEPROM)
- 16x2 LCD display with backlight
- Three Buttons
- One of the eight analog inputs
The temperature probe was constructed using a two foot long piece of copper tubing and a TMP36 temperature sensor. The copper tubing is the type used to run a water line to a refrigerator ice maker. The TMP36 fits perfectly inside the tube.
The steps to make the temperature probe:
· Straighten the desired length of copper tubing.
· Crimp one end and seal it with a non-lead based solder.
· Use heat shrink tubing for each lead to insulate each lead soldered to the each of the three wires.
· Insert the sensor and wire into the open end of the tube until it hits the bottom.
· Seal the opened end with silicon sealant. This end should not be submersed in the liquid.
· Wrap this end with a thermal insulation material such as foam or vinyl tubing so the probe can be handled safely when removing it from a hot liquid.
At some point I will decide on a water resistant case for my BrewMon project. For now I am just using a plastic baggie.
Here is the code: BrewMon.zip
Enjoy and if you are ever in the area visit Keystone Homebrew Supply.