Brew Controller: Finishing touches

I got the panel completely wired and partially tested. I had to figure a way to turn on the SSRs for the pumps without using the SSR output (Can’t write to the modbus register while in operational mode). I decided to just run through one of the alarm relays and run that way. It works great and turns on my drill, lights, etc without issue. Didn’t want to test with dry pumps.

I spent some of last Sunday getting the finished panel mounted to my brew cart. Just had to adjust the shelves and create a mounting plate and bolt right up. I still need to mount the pumps. Also mounted my Touchscreen computer to the wall close to an outlet. I didn’t want it on the cart itself, but in the shade just inside the garage. I realized the power supply also has a 2.5A USB power port on it, so that’s handy.

The new twistlock plugs were wired to the heating elements I had. They were hardwired to a dryer plug before when I was doing extract brews, so just needed to wire in the new cable and plug. I haven’t tested them yet, as I finished late, but it’s close. The temperature sensors still need thermal compound put inside them, but are otherwise working and measuring temperature.

Also embedded a nice little countdown timer (preset for 1 hour, but changable). Its just an embedded website, so I’ll likely update it later. It works for now though.

So all that is left is mounting the pumps and filling the HLT and BK with water and running the autotune on the PID’s.

Here’s some recent pictures:

Brew Controller: Panel Wiring

Another little update. I’ve been working on the interface some more, as well as getting the panel wired up. I still need to get the low voltage stuff wired to the PID controllers, get the modbus wired and install the wifi dongle/antenna cable.

I’m using some of the unused outputs (alarm ouputs) on the PID controllers to drive the SSR’s for the two pumps. I’ve also wired the E-Stop to the coils on the two 2-pole contactors for the heating elements in case I need to shut down. This will let me keep control power live.

The PID’s have a nice feature on them where you wire in a Current Transformer. This will let you see how much current is going through each SSR. This allows me to ensure that I can tell if a heating element is open circuit if the SSR is on and I see no current, or that the SSR is shorted if the SSR is commanded off and I see current.

Also, since then, I got a medical grade Touchscreen computer and a mounting arm off eBay. This will be my new interface for the brew panel, and will also allow me to check on the temp chambers. Here’s a video of the interfaces of both:

Here’s some pictures of the LCD touchscreen computer:

And some pictures of the panel:

Brew Controller: Assembly

I made some more progress on my electric brew control panel this past weekend. I got everything mounted and ready for wiring. Just some small tweaks and a few more parts and I can mount it to the wall and take it for a spin and brew some beer.

This week I’ve been working some on the HMI that I’ll be running on the Raspberry Pi. I’m not changing a ton of the layout, just getting more of the Modbus Registers added and configured. I’m going to use the spare outputs on the PID controllers to drive the SSRs for the pump motors. These Eurotherm PIDs have a Current transformer input that can monitor the current going through the heating elements. This will help show if the SSR is shorted and also I can guesstimate instantaneous power.


Kegerator: Mycodo

So I’ve spent a few weekends the last couple months trying to get the control system on the Conviron kegerator worked out. I wanted to use some of the PID controllers I bought, but they seem limited in they don’t have a on-time delay and off-time delay, no ramp/soak and limited output options. I don’t want to short cycle the compressor, so controlling the on and off times and delay between is a must.

When I was first planning the build, I looked into some other software that does controls for homebrewers. There’s Craftbeerpi, Brewpi and a few others. I stumbled upon another software that runs on the Raspberry pi, that was geared more towards plant and mushroom growth, called MyCodo, by Kyle Gabriel. I was hesitant at first because I don’t have experience with the DS18B20 temperature sensors.

So after months of tinkering, I decided to give it a shot and I’m really glad I did. Not only did it eliminate my problems, but it has some features that I really wanted to have. It turns the kegerator into a full temperature controlled chamber, with a receptacle inside I can control on and off if needed. I can control the heating and cooling solenoids on the heat pump, the compressor and fan, and display humidity, temperature etc. depending on sensors used.

One really awesome thing it can do, is use methods to change the PID setpoint over time, i.e. ramp/soak profiles for lagering and cold crashing.

I wired it to drive some SSR’s directly to control the compressor/fan at the same time, and heating/cooling solenoids independently as needed. I know the kegerator won’t need heating, but it’s just another cheap SSR, so I’ll wire it in and if I need it, it’s there. Once I prove it out, I’ll gut the controls on my other Conviron chamber, and overhaul it. Chamber 2 already has Temp, humidity and light control which I want to keep. The thought is, I can use it for fermenting as well as growing mushrooms, growing plants, etc.

Here’s a picture of the MyCodo interface showing some of the outputs, temperature and the graphing abilities:


Kegerator: Update

It’s been a pretty busy summer, so some of my projects were put on hold a while. A few weeks ago, I got new taps and drip-tray and installed into the temperature chambers. I spent a little while since then removing any unnecessary electrical components on the chamber that were left over from the broken controls. I also worked a bunch on the new control system using the Raspberry Pi.

New chamber fits roughly 9 corny kegs in the bottom, and has room up top for cheap beer, bottles and beer glasses. The chamber has a hole in the top that will house a 7″ touchscreen LCD that will eventually show a tap-list running on the Raspberry Pi. Also running on the RPi, is an HMI that I created (using the same software for my brew control system) that will allow me to set the temperature and view alarms. I can even set it to email or sms message me if an alarm threshold is reached.

Next up is wiring the SSR into the existing components and getting just the cooling working. I’m hoping to have this finished in the next couple weeks. I’m running out of space in our fridge for beer, and need somewhere cool to store everything.