How to: Raspberry Pi HLT/Boiler Controller

[Robbo100]

Great news! I am not sure what you mean about "the two bus pins"

So should the bus number for Rev 3 board be 1, the same as Rev 2?

 

[Robbo100]

And was this with your new RPi, or the old one?

 

[Pakman]

Robbo

This is with the old board. The new one is not due for a couple of days.

The Rev 3 board has Bus 0 not 1.

I used the pull-up resistors on the SDA and SCI lines (pins 3 and 5 on the Pi I/O header)

Graham

 

[Robbo100]

Where did you find out that the resistors would help?

 

[Pakman]

Searching through lots of Pi reference sites with the phrase I2CDETECT revealed several issues with the response I had of all addresses from 3 to 77 being filled. Pull-up resistors were deemed to be the answer. However - Having rebuilt the software onto a new SD card as part of the fault finding my old card still shows up the numerous addresses but the new one just shows 20 - they both now start the Boiler_Controller software OK.
Will try and sort the switches out tomorrow.
Graham
P.S. New Pi has been despatched.

 

[Robbo100]

How are things going Graham?

For anyone interested, I have just finished the software for the dual purpose Boiler/HLT Controller and Fridge Controller, which is working very well. I am in the middle of testing now, and will release the software (if there is a demand for it), when I am happy that it works.

Here is a link to the update: http://www.thehomebrewforum.co.uk/viewtopic.php?f=23&t=49311&p=484949#p484949. I wish my AG Beer was tasting as good as my RPi code was working! :wha:

 

[Pakman]

Latest update -

New Pi received, this is an RS unit unlike the previous Element 14 one - it's a revision e :wha:

Everything works as YOU designed it to! (after I removed my change to Adafruit_I2C.py) Expansion board at location 20 on bus 1. Both HLT and full boil mode works fine - tested temperatures by holding sensors near my soldering iron etc. etc. everything is fine. :party:

Obviously there is something wrong with my first board as I was unable to get the switches to work even though the software appeared to be running OK.

Thanks for your patience. I'll have to see if the old board works well enough for my serial datalogging task as that will not utilise the I2C bus. :hat:

Graham

 

[Robbo100]

Brilliant news. I am delighted, as I was a little worried I had made a mistake and you might be spending money fixing a problem that was my fault!

 

[Pakman]

Managed to get the other Pi to store the output from a USB GPS onto a log file yesterday so things are looking promising for it not being completely dead. :thumb: Just got to manipulate strings now so that I only log the bits I want from the NMEA GPS data stream. :hmm:

Back to brewing, did a Wilkos Fruits of the Forest cider yesterday - that's two sequential brews for SWMBO. :

Graham

 

[Swift Pint]

Looks great Robbo! :thumb:

Any reason why I couldnt use this to control my mash and then boil in a BIAB setup?

What sort of accuracy are you getting on temperatures and what sort of lag time in getting up to temp?

I guess I want to make sure I can control my mash temps to a reasonable accuaracy.

I'm currently using a brewpi for fermentation temps, and had considered modding that for mash temps, but haven't had the time to look into it!

 

[Robbo100]

What is your mash setup? How are you heating the mash tun?

In theory there should be no problems controlling within a degree or so.

 

[Swift Pint]

Great! :thumb:

I'm still thinking about my setup, but I think its going to be a thermopot with an element at the bottom, false bottom to keep the bag & grain off the element, and maybe a small pump re-circulating wort from the bottom of the pot to the top. (still at the idea stage!)

 

[jonnyconga]

Robbo - this looks awesome - been looking at your other thread too. Had a Rasp Pi since they were released but don't know a hole lot (nothing) about coding so never really got on with it. I don;t have time for this project at the mo but it definitely one of those "one day I'd love to..." sort of things. Love to learn how to do a bit of coding too.... again.. one day I will....

Also - people have mentioned getting cheap components from China - is that just via Ebay?

 

[Robbo100]

Thanks

It is all pretty easy once you get into it.

The stuff from China is an option and yes, it comes via eBay. I tend to get stuff from eBay too, but only for for UK suppliers.

 

[peeltone]

Hey Robbo

Great project, how are you doing with your revised code for Friday control etc.

Cheers

 

[Robbo100]

Hi there.

Well, I have had three disastrous brews, which I have put down to the fact we live in a very hard water area and I never descale my kettle elements, so I stopped brewing for a while. I haven't quite gotten round to emptying the 160 pints of wasted beer down the drain yet :-(

So anyway, it means that I sort of paused fiddling with the controller, because I couldn't bring myself to progress something which was generating such rubbish beer.

Anyway, now that I am happy that I have found the brewing problem I will pick it back up again.

I am aiming to simplify the install process by having the thermometer addresses stored in a .dat file (so the user doesn't have to modify the code). I also want to make it so the programme (along with graphing tools etc) are all automatically downloaded and installed from a simple script.

I can upload the script as it currently stands, but need to get my head back into it to make the final settings all work.

Sorry for the delay.

Are people actually using it?

 

[yoyomet]

This is a fantastic effort - not just doing it but the documentation is superb. I'm definitely going to do this when I get to the equipment build. Right now I'm just clearing the shed and putting up the shelving for the brewery.

 

[Robbo100]

@Pakman,

If you are watching this thread - I tried to PM you, but your setting for the forum are blocking all PMs.

Could you let me know if you are able to change your settings so I can ask you a question.

Thanks

Robbo100

 

[Pakman]

. . . but not been around much recently - however, I've just picked up a brewing fridge whilst working in Wales. Go ahead with your question.
Graham

 

[Pakman]

I'm still here Robbo, just not been on recently due to being busy elsewhere. I have just purchased a brewing fridge so will be moving my STC1000 to that task and using the Pi to do the HLT instead.
Graham