RasPi Brewing controller

[Buri]

Hi
Here is my project to get Single Vessel Brewing going.
I will post pots and hardware later as it's not near ready.
However I'd like to share some electronics stuff it just needs a box now. all the other stuff is hoked up and ready.

1. I use Raspberry Pi.
   I come a long way form Arduino to rasPi+ Arduino to rasPi only.

2. I ported brewtroller to python (ugly version) and hacked it for single vessel. Code is still need a lot of work. however it works end to end now.
it is a simple raspi deamon with web server that drives UI and user controls. I don not use LCD for simplicity sake.
however I can do all possible step brewing programs

     https://github.com/theburi/RasPi-Brew - Python script that runs as a demon
     https://github.com/theburi/raspi-brew-www - Web site that shows progress and takes User input.
3. I am fairly sure I finalized a list of electronic components.

So Python script runs at a background and controls Sensor, relay and executed a program.
Web site reads different stat files and if User Input is needed shows buttons and stuff.


If you guys are interested in contributing I would be more then happy.

I only tested it with a sensor in a kettle, but it worked great.


Some more comments:
the reason I abandoned Arduino were: C; hard UI and user input
I also found uln3803s chip that buffers and amplifies  RasPi outputs. Making outputs 5V and with enough power to drive relays. This chips makes relay switching dead easy and safe.
I also found a way to read 1wire devices (thermometers) with rasPI without any extra bits. it was finally added to rasPi kernel.

I use ATX PC power supply that drives my Pump with 12V and RasPi 5V
And a standard commonly used Power 25Amp relay to switch heating element as well as 5v relay for the pump

Since it is a brewtroller port, adding multipot setup should be fairly easy. However this program need to be rewritten to use python properly.
I moved away from PHP in a web server to keep everything simple.

[imark]

Interesting! haven't used brewtroller. What's your setup? More details please.

[Stitch]

Arduino will not crash as it is an embedded device. The raspberry pi has a tendency to crash. Using both and keeping control on arduino ensure that if the pi crashes then the process does not.

[Buri]

So stability of RasPi is not an issue. Whole process runs for few hours with very simple load. RasPi runs is not stable when we talk about weeks. I would not worry about it.
Even if that will become a problem a simple state persistence would address it. I could wait for 20 sec to reboot RasPi.

The main advantage is development speed. Arduino is hard. (er). slow and nightmare when code needs to be changed, debugged, tested etc.

Also I wanted to have Web interface so I can use my mobile and not LCD to monitor the brew. It just makes Input/output much easier to build and use (imho)

The brew set up is not finished - 50% complete. And I hit an issue as my heating element  broke so I need to replace it.

But it would be a clone of Braumeister build out of keg and a pot as a malt tube. I'll post pics as soon as I can have something to show.
New Heating element will be ceramic hob heating element under the keg. (testing atm) ( I just have one lying around so why not use it)

[Will_D]

So a R-Pi is prone to crash after a few weeks 

WHY?

Software: You can Crash a computer by dubious software (like allowing div by zero), poor memory addressing (getting data/instructions from outside your allocated memory) and so on

Hardware: Dodgy Chips/timers/what ever (like poor thermal design, induced emf) else.

Most of you are too old to remember a certain scandal whereby a large US chip manufacturer (who was so confident they printed the state map on the package) packaged up some chips in a mil-spec/space-spec ceramic package. They issued all the certifications. UNFORTUNATELY they forgot to run a simple radiation test on the ceramic substrate ingredients or the finished chips.

So they packaged up chips, sold them to us, with an unfortunate built in memory bit flipper (also called an alpha-particle emmitter) - not the sort od RAM you need. When they say Random they don't mean the randow chance of getting back what you stored there.

SO: Why are R-Pi's unreliable?

[mr hoppy]

If we're too old to remember have we gone senile?

[HomeBrewWest]

I live the PIs, but Java's exception handling is one of the reasons I write everything in Java. I think a JVM has just become available for the PI.

[Stitch]

Java is just massively complex. I have programmed a lot and I find java to be the hardest to use. The only benefit is that it is platform independent and as an android lover you are kind of stuck with it. The problem with the pis (imho ) is that they are open source developed by two people and you really get what you pay for. I worked for a company a few years back who produced automation controllers. The core chip could allegedly run inux. We forced on a copy of DSL (damn small Linux) with 64mb of ram which worked OK but again it was on 40 euro worth of hardware so performance was not great. The arduino in fairness is well designed for what you get. 

Sent from my Nexus 7 using Tapatalk

[JD]

Java ...only benefit is that it is platform independent

Yeah, right.

:

[Buri]

Latest: Today something (heating element) got burned, that generated a spike and it looks like RasPi GPIO got burned out, well it's black and RasPi would not boot. So a set back. 

[imark]

SSR the way to go with next build Buri

[JD]

Opto isolated SSR protects against anything on the hi voltage side from getting back to the low voltage side.

[Buri]

No. What happen was that apparently my DS18b20 steel shell was connected to the ground inside a connector and looks like a power surge fried ground connectors and my temp sensor.