BrewMonitor project

[contrarian]

Looking good Michael, the end game is especially interesting.

But seriously, I have a hard enough time concentrating at work as it is without being able to monitor fermentation from my phone!

 

[Logan_01]

Just thinking on this load cell idea. A loadcell with a +/-1% accuracy would still give you a +/-200g reading on 20kg. To get to +/-1 gram at those weights means +/-0.005% accuracy. Without looking, I would be suprised if loadcells and the amplifiers would be able to achieve this. maybe NASA might have some, don't know.

 

[DJ_L3ThAL]

http://gedgesystems.com.au/main/Load_Cell_GK2101S.htm

0.02% accuracy which is about 4-5 grams over a single homebrew batch amount. Thats pretty accurate for this purpose if it suits and isnt $1million

 

[Logan_01]

Maybe you should enquire and get a price, will probably need 4 of them to balance the platform the fermenter sits on. No good getting high accuacy load cells without a high accuracy controller, so best get a price on one of those to. I recon you might get out with $5k, but we will see.
I personally like my $10 hydrometer which can determine 0.001 sg or 1g in 1kg.
To automate I would make something to measure hydrometer level, but would have to deal with bubbles or touching the sides.
Na too hard, just take the reading at the end, and drink the beer.

 

[Mr. No-Tip]

I think the end game really needs to be a temperature controller. The thing we are missing is a smart temp controller that is also legal in Australia. STC1000 and Brewpi's with SSR's aren't legal.

What is the legal issue?

 

[MastersBrewery]

Or do what one of the HBT'ers (malffet or something like that) did and use a mass flow controller and measure Co2, also means your under pressure though, but accurate to .ooo5 (the new and improved WW?!!)

 

[goatus]

What is the legal issue?

I think he means illegal to wire up the 240 side without a sparky licence.

 

[Spiesy]

I think he means illegal to wire up the 240 side without a sparky licence.

Any many are sold already wired up, illegally. They don't have Australian compliance - look in any HB shop and you'll find them.
Doesn't mean they aren't safe, the manufacturer just hasn't been able to justify the $10k to get compliance.

 

[megabyte]

Unless you're conducting nuclear reactions inside the fermenter (changing mass to energy or visa versa E=MC^2), net change in mass = mass of escaped matter. In this case, CO2 (and any samples taken or moisture ingress which has then condensed).

The yeast doesn't appear from nothing, it simply grows from molecules which were already present.

I thought the same at first but the idea is that we want to measure the change in weight of the wort, exclusive of the yeast. So if some of that wort mass is turning into yeast instead of alcohol then we need to account for that. This has also been covered on HBT forum but the good news is it's purely Newtonian physics and predictable enough to model with a simple equation.

1 g glucose => 0.46285 g CO2 + 0.48391 g ethanol + 0.053 g yeast

Looking good Michael, the end game is especially interesting.

But seriously, I have a hard enough time concentrating at work as it is without being able to monitor fermentation from my phone!

But that's why it only notifies you when important conditions are met, that way you can give your work your full attention without worrying how your yeasties are tracking back at home. Admittedly, I too would still be inclined to check up on progress during work hours though. We'll know we've made it when IT admins start blocking BrewMonitor traffic along with facebook!

 

[contrarian]

If they really want to increase productivity you'd have to check your smart phone at the door before starting work!

 

[kaiserben]

I'm trying to make a Raspberry Pi monitor and control ferment fridge temps (and then also log data and transmit it via wifi to a webpage).

Every controller I've read about always uses extra boards (arduino etc), so I'm wondering if I'm missing something here, but why can't I just create and run a simple program & webserver for the Pi to switch the relays on/off at certain temps and hold for certain lengths of time?

 

[megabyte]

Hey @professional_drunk, I'm still busy coding pushover and thingspeak integration today but I've also been thinking about your rf power sockets as an option for the future. Are these the kinds you used? They are surprisingly cheap at $13 bucks a piece!

 

[vortex]

I'm trying to make a Raspberry Pi monitor and control ferment fridge temps (and then also log data and transmit it via wifi to a webpage).

Every controller I've read about always uses extra boards (arduino etc), so I'm wondering if I'm missing something here, but why can't I just create and run a simple program & webserver for the Pi to switch the relays on/off at certain temps and hold for certain lengths of time?

You can. I am working on a project that does this now with an I2C relay board connected to a RasPi to switch relays. No need for the Arduino, a multi threaded Python script (well, collection of scripts) does it pretty well. Mine controls 2 fridges with ambient, fridge-air and wort temp sensors in each.
I'm happy to start a new thread and point to code (it's not yet ready to control a ferment though it should be said) so I'm not polluting this project thread.

 

[professional_drunk]

I'm trying to make a Raspberry Pi monitor and control ferment fridge temps (and then also log data and transmit it via wifi to a webpage).

Every controller I've read about always uses extra boards (arduino etc), so I'm wondering if I'm missing something here, but why can't I just create and run a simple program & webserver for the Pi to switch the relays on/off at certain temps and hold for certain lengths of time?

Why not use just the Raspberri Pi without an Arduino?
There have been examples of brewing controllers that use the Pi’s GPIO pins intead of having and Arduino slave, but having a slave is a deliberate choice for me. The main reason for this is that the Pi is not very stable. I have had it crash on me multiple times. So what happens to the GPIO pins when it crashes? Will it just keep cooling your beer to 4°C and stop your fermentation?
The Arduino slave simply will not crash. Even if the Pi crashes, the temperature control keeps running. Your beer is safe. The worst thing that will happen is that it will not get a new temperature from the temperature profile and no data will be logged.
A microcontroller is better suited to interface low level hardware. The Pi is better suited to log data and provide an interface. I think it’s a better design this way.

 

[vortex]

That has not been my experience with RaspberryPi's.

 

[professional_drunk]

Hey @professional_drunk, I'm still busy coding pushover and thingspeak integration today but I've also been thinking about your rf power sockets as an option for the future. Are these the kinds you used? They are surprisingly cheap at $13 bucks a piece!

That's the one.

 

[kaiserben]

Why not use just the Raspberri Pi without an Arduino?
There have been examples of brewing controllers that use the Pi’s GPIO pins intead of having and Arduino slave, but having a slave is a deliberate choice for me. The main reason for this is that the Pi is not very stable. I have had it crash on me multiple times. So what happens to the GPIO pins when it crashes? Will it just keep cooling your beer to 4°C and stop your fermentation?
The Arduino slave simply will not crash. Even if the Pi crashes, the temperature control keeps running. Your beer is safe. The worst thing that will happen is that it will not get a new temperature from the temperature profile and no data will be logged.
A microcontroller is better suited to interface low level hardware. The Pi is better suited to log data and provide an interface. I think it’s a better design this way.

Interesting. We'd been looking at the BrewPi set-up but hadn't seen that text. My tech guru had been wondering if people had simply copied/improved older controllers and, even as technology developed, just kept using arduino because it's the way it has always been done. He's determined to use the GPIO pins so I guess we'll see how it goes.

Ultimately we want the Pi to control a brewing system as well as a ferment fridge.

 

[professional_drunk]

Please excuse the dodgy video quality. Note that the arduino is 1.5m away without an antenna for the rf transmitter.

 

[vortex]

Interesting. We'd been looking at the BrewPi set-up but hadn't seen that text. My tech guru had been wondering if people had simply copied/improved older controllers and, even as technology developed, just kept using arduino because it's the way it has always been done. He's determined to use the GPIO pins so I guess we'll see how it goes.

Ultimately we want the Pi to control a brewing system as well as a ferment fridge.

Like I said, but was subsequently ignored, it is easy to do and does work without an Arduino. The RasPi is NOT unstable as the BrewPi guy says. It's more likely something was wrong with an individual RasPi, unstable power input (they can be quite sensitive to this), an SD card issue (the OS can block when reading or writing from bad sectors on the SD card) or the software on it at the time. We have 3 RasPi's that get extensive workloads (for Pi's) in our house and they never "crash" or become unresponsive in any way. We have used everything from the very original 256mb RAM Pi up to the latest RasPi 2 and all have been stable and excellent.

Also, Pi's are cheap enough you can have separate ones for ferment control and for the brewery, this is my approach.

Additionally there are other SBC's available such as BeagleBone which do similar things and they have basically the same amount of CPU & RAM (but a shitload MORE GPIOs)

But as I suggested we avoid earlier, we're polluting an unrelated projects thread.

 

[mr_wibble]

I'm trying to make a Raspberry Pi monitor and control ferment fridge temps (and then also log data and transmit it via wifi to a webpage).

Every controller I've read about always uses extra boards (arduino etc), so I'm wondering if I'm missing something here, but why can't I just create and run a simple program & webserver for the Pi to switch the relays on/off at certain temps and hold for certain lengths of time?

I'm not trying to be a **** - but why not just use an Arduino then ?

For ~ $5 you can get a no-name brand Arduino Nano.
Wire the temperatures sensor(s) and SSR(s) to it, and read log-data and write commmands from Mr Pi over USB/Serial.

I fully understand that you might want to use a Pi for it "just because". It's just that on an Arduino it's cheap & easy.