I’ve been brewing a lot of beer lately. One thing I’ve learned is that its important to be able to control the temperature of the beer during the fermentation process. To that end, I’ve designed and built the “Ferminator 2000”:
It has the following features:
– Two FET’s to control heater/cooler
– Three inputs: two thermistor inputs and a thermocouple input (Type K)
– SD card for config storage and logging
– Onboard FTDI for usb->serial comms
– DC/DC converter so that the uC power can be pulled from the drive voltage of the heater
– Accurate RTC for time-keeping (added to the second revision).
You can find the board files and the software (still in development) at http://www.github.com/esoren/ferminator2000.
It can be used to drive almost any kind of heating/cooling element. I used some flexible heaters that are normally used for heating the beds of 3D printers. By wiring three of the heaters in series (24V), they draw about 60W. This is enough power to heat up a 5 gallon carboy of beer by 5 degrees Fahrenheit per hour.
I’m still (slowly) working on the Software. Each of the blocks appears to be functional, but I need to setup the whole thing with a gallon of water before I risk it on any beer.