I brew like a simple pot on a stove. Because I think it is important to brew in a reproducible way I use automation to achieve this. Actually I use a predecessor of Tcontrol to control all the mash steps temperatures and timings. All the brewing is done without a pump. The inside of the kettle is RVS the outside is iron.
Mash tun with stirring motor on top and direct heater which is controlled by a proportional valve from a central gas heater. A handmade PCB with some I2C components is the interface to the parallel port of the brewing PC.
The stirrer used in the kettle is driven by 24 Vdc which is speed controlled by the PC depending on the heating in the last minutes.
On the brewing PC I fill in the mash scheme for this beer.
The home made brewing program is called BeerPID. The program BeerPID is not a PID controller anymore but uses a feedback an feed forward analog algorithm. Digital temperature sensors measure the temperature of the wort.
This photo shows the bottom side of the mash tun during heating. Also the wiring of the electrical ignition and the flame monitoring sensor can be seen.
After mashing the mash tum is hoisted on the counter with a electrical cable hoist.
The heating of the sparge water is automatically started after the mashing and regulated to 82 degrees Celsius during the sparge.
The sparge water bucket is about 25 liter. It contains a chip fryer heating element mounted 4 cm above the bottem into the water.
After filtering and sparging the boiling starts.
The software detects the start of the boiling so the first hop can be added. A timer on the screen is used to give alarm when next hop or sugar should be added.
Good to hear the reactions. To see it live in person is probably difficult due to the distance. But looking this video from a few years ago gives a good impression how I brew. https://www.youtube.com/watch?v=7T6Whz4tzjw
Tomorrow I’am going to brew an American Pale Ale. If there is interest I will make a topic about the fermentation of this beer. Including the fermentation result in time measured by the CO2 production sensor.
Let me see if I have your PC interface schematic figured out correctly. It looks you are bit-banging data bits out on pin 6, generating the I2C clock signal on pin 5, and bit-banging data bits in on pin 13 (bits are inverted from what appears at the base of T1). You have pins 10, 11, and 12 gated out such that they source current and serve as VCC for pin 8 with R4 acting as the collector load resistor on OK2. Pin 25 is signal ground. The optocouplers isolate the board power supply from the PC power supply. Am I close?
And Windows is not so good when you have real time interrupts that need to be dealt with. It usually prioritizes it’s own first, like updates and other outside world stuff. For good process control a RTOS is almost essential. But you guys know this already. A lot depends on how much you have going on, just controlling temperature or handling functions that occur over minutes as opposed to milliseconds it may work OK. I’ve seen it go both ways depending on the application. Cool system. I’m a little hesitant about putting heaters in plastic buckets. A single fault and you may have a fire if there is not water there.
The cycle time for my Labview applications is 1 second so it is not very hard real-time. But you have a point for more time critical processes.
The heater in the plastic bucket is no problem when there is at least 4 liters of water in it. With less then 5 liters of water in the bucket I disconnect the power to the element. And also the chips fryer element has still two protections against overheating. The first is the original thermostat which I set to 90 degrees C and the second protection is the original overheating protection of the chips fryer. Both are in series with the PC temperature control and switch off if over temperature is reached.
