craftbeerpi control panel

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BierMeJohn

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Hi All,

After months of searching posts here and on the cbpi facebook group, I'm close to starting my build. I'm looking for some constructive criticism/pointers/tips on the attached schematic for a cbpi panel I'm hoping to start ordering parts for in the near future. It's intended to control a 240V 30A, 2 x 5500W element (only one on at a time) system plus a fermentation chamber. It's meant to be more of a conceptual drawing so I wasn't overly concerned about having every single wire laid out on the schematic. Thanks in advance!


CBPi_ContolPanel.png
 
Forgive my ignorance, but why do you need all the relays, breakers and switches ? I'd get rid of everything I could. Your control box should be protected by a single GFCI at the breaker box.

When you do a wiring diagram like this it helps greatly to color code the traces, especially ground (green) hot (red and black) and neutral.

If you are running CraftBrewPi, you dont really need the touchscreen nor the Cat5 connector. A tablet works great for running CraftBeerPi over wifi. You can do all the admin over ssh.

If you want an estop, bring all the grounds for the relay board and the ssrs to a common point and put the estop there.

The Rpi needs 5v or 3.3v. Where is your supply for it ?

You don't need XLR connectors for 18ds20 temp sensors. I'm using 1/8th inch stereo jacks. You need a 4.7K ohm resistor between V+ and data as well.
 
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@brewman ! It looks like the OP is powering his Pi with the 12v power supply to the CBPi expansion board (hat) which is the way most of the expansion boards are set up. The expansion boards also have the 4.7K resistor already wired to the inputs for the sensors.

It looks like the emergency stop is wired to kill power to everything except the Pi which makes some sense since the Pi OS can have corruption issues if you don't shut it down properly through the software.

Some people have reported wifi issues with the Pi if they have built their controller in a metal enclosure unless they use an external antenna or wifi dongle so that may be his thinking for the network connection.

As for the rest of the design, other than seeing some of the same components I've seen in other designs, it's beyond me. I'm sure some of the experts here will weigh in.
 
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@Brewman, thanks for the input!

@Gravitysucks is right on with his answers.

Based on other comments received in a different forum, I've removed the breakers from my design. I included switches so that I can manually power the elements if I need to.

The touchscreen and cat5 connector are just a matter of preference.

Thanks for the tip about color coding the traces, that's a great idea!
 
Each to his own, but I just built a very similar system and did not find any need for the breakers, switches and relays, nor the touchsceen and io board.

I love operating my brewery from a 10 inch tablet and monitoring things from whatever device I have near me. I love that I can move the tablet wherever I want while brewing. It runs on its battery and connects via wifi so its totally portable. I place it wherever I'm working so I can always see what is going on. i don't have to be in close proximity to the kettle and I dont have to keep looking in the direction of the brewery. I can be washing things up or preparing yeast or weighing hops or putting kids to bed and still see exactly what is happening.

Fyi, if you wire the estop button into the grounds of only the relays and ssrs, the rpi can keep running after an estop.
 
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Each to his own, but I just built a very similar system and did not find any need for the breakers, switches and relays, nor the touchsceen and io board.

I love operating my brewery from a 10 inch tablet and monitoring things from whatever device I have near me. I love that I can move the tablet wherever I want while brewing. It runs on its battery and connects via wifi so its totally portable. I place it wherever I'm working so I can always see what is going on. i don't have to be in close proximity to the kettle and I dont have to keep looking in the direction of the brewery. I can be washing things up or preparing yeast or weighing hops or putting kids to bed and still see exactly what is happening.

Fyi, if you wire the estop button into the grounds of only the relays and ssrs, the rpi can keep running after an estop.
Yeah, I get what you're saying and that's cool. Believe I'll be able to monitor the process from a tablet regardless of the touchscreen. Honestly haven't given much thought to walking away and doing other things. But it's good to have options. When I am in my brewery I want to have a display that's always on and in one place (so I'm not looking around for where I sat my tablet down), but that's just me, I like what you're saying about the portability.

That's my intent, that the estop kill the pumps and elements and the pi keep running. Do I not have that wired properly?
 
CraftBrewPi supports an unlimited amount of clients, so you can monitor and control from the touchpad and remote device(s). But... you won't be able to override any of your manual switches. I like having everything controlled by CBPi. I don't see the need for manual switches at all.

Look at the interface for the new GrainFather controller. There are buttons for changing temps, but who uses them anymore ? Everyone does things from their phone.

As far as walking away, I like moving the tablet right in the brewery. If I'm washing up the mash tun, I can move the tablet so it is right there. I'm waiting for the boil to start and I can watch the temp climb right there. I don't have to walk away from the sink and look at the kettle. I like this so much that I'll probably add a camera to the RPi so that I can actually see the kettle.

If you want the display always in the same place, put a mount for the tablet in a standard place and put the tablet there when you are working by the kettle.

Samsung 10 inch tablets have excellent displays, are fast and work well for this. You can pick up a used one cheaply. They run a web browser much nicer than an RPi will. I like editing recipes and steps much better on a tablet (or a desktop PC) at a desk than standing in front of the brew kettle on a touchscreen.

I get why you want a mounted control at the front of your brewstand. I might make a mount for my tablet on mine. I'll see how the next few brews go.

As far as using manual switches and the estop, you can accomplish everything you want without the use of the power relays. See my attached diagram.

Edit: I'd put the CBPi (Auto) input on the center pole of the switches instead of the top contact as I drew in the diagram. That would allow you to go from Off to CBPi auto control without going through the On state.

20190120_122721.jpg
 
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Thinking out loud, it would be pretty easy to wire up buttons to an ESP8266 and have it send messages to a CBPi controller or wire buttons directly into the RPI and have them as inputs to CBPi. That would be better because the remote sessions could at least see (and overide ?) the state of the buttons, instead of assuming that the process is under CBPi control.

With the buttons wired in to overide CBPi in your system, you never know if CBPi is actually controlling the process or not. That would bug me. I am very sure that I would leave a button in the ON position instead of under CBPi control and flood something or overheat the mash or have a boil over. But maybe that is just me.
 
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I am impressed with first picture. Good job.

SSR have tendency to fail shortened. It is important to protect from that.
I fully support your 1st diagram and I think it's an idea in good direction.

Did you developed it more? How to detect if SSR failed and shortened , how to protect wort to over cock? Any ideas?
a) 2 SSRs in series ? would that be an option.
b) use relay you have in series, but use NC- that relay is on another GPIO and another temp sensor.
Its confugration is alway +10C as protection temperature. if goes over it disconnects....

It would be great to hear ideas about good protection.

As engineer I always think worst case scenario...
 
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