1-Wire Fermentation Control System

[tharding]

Over the past couple of years I have put together a fermentation control system that allows me to control the temperature of my fermenting wort.
The system allows me to monitor and control the temperature to 1/10 of a degree of the target temperature using a 1-wire control system.

When I started brewing a few years ago I quickly learned that if you wanted to make great beer you needed to control the temperature of the fermenting wort to get the best qualities of the yeast and to help eliminate the production of off flavors. I am still working towards making great beer, but at least the fermentation process is now automated.

I will go over all the components of the system over the next few weeks, so others can utilize what I have developed.

Homebrewing is about giving back to the community.

Have a great day and I will post again soon.

 

[Zaphod]

Can't wait to see more of this!
From your diagram, I currently don't see anyway to heat your wort, is that correct? I see you have a cooling system going, but can you warm it up?
I'd love to see specifics on the remote monitoring.

 

[tharding]

You are correct there is no way to warm up the wort.. I can ramp up the temperature of the wort simple by setting a higher target temperature.. The temperature of the wort will ramp up at a very slow rate due to thermal loss of the cooler, approx. 1 degree or so every hour. I only ramp up the temperature of the wort at or near the end of the fermentation cycle to squeeze some more life out of the yeast.

When i put the carboy in the cooler I make sure that the temp is within 5 - 10 degrees of my target temperature as it will take a few hours for the temperature of the wort to drop. If I am to far away from the target temperature I will put the carboy in without the yeast until my target temp is reached or throw the carboy in the refrigerator to cool it quickly.

 

[Zaphod]

I guess being in AZ, you don't really have that problem. Whereas I sometimes do being in CO.

 

[tharding]

I actually ferment inside so outdoor temp is not any issue.

 

[dbrewski]

Cool! Tell us more when you can. I was looking at 1-wire components the other day at phidgets.com. it looks a little intimidating, but I'd love to figure it out. I have a lot of old PC's and what not sitting around that could access my wifi so I could remotely monitor...I have a poor man's lagerator out in the garage I'd love to monitor too.

 

[tharding]

Zaphod,

I was thinking about the heating function, the system could be changed to use a carboy heating jacket like Fermwrap. The switchable 110v module could control the on/off cycle of the Fermwrap and you would still use 2 temperature probes. 1 attached to the outside of the carboy and the second one inside the wort. The controller software would need to be changed for a heating function which would not be a big deal.

It also looks like the carboy may fit inside the gott cooler to give some thermal stability to the system.. So at first glance it should not be a big deal to add a heating mode to the system.

 

[tharding]

Here is the gott cooler from HD it is the 10 gal cooler which holds a 6 gal carboy with only a small mod to the lid. You can see in the picture the 1-wire temperature probe which measures the temperature of the wort.

You can also see the 2 rubber tubes which connect to the heat exchanger coil inside the cooler. Between the 2 tubes is the 1-wire temperature probe which monitors the temperature of the bath water.

The lid can be easily removed for visual inspection of the fermenting wort.

 

[Homercidal]

Nice! I had a similar idea but not using a fridge, just another cooler with an ice block in it. Too many projects going to actually build it at this time though.

 

[tharding]

Here you can see the stainless steel temperature probe which monitors the termperature of the wort.

The probe is a 1-wire device that was built using a 16" steel probe from brewers hardware. I had them make me a longer one so it would reach the middle point of the wort. A DS18B20 ic from Maxim just fits inside the tube so it could be inserted all the way down to the tip of the probe. The connections to the ic were heat shrink wrapped to eliminate any shorting of the leads to the shell. I also added some heatsink gup to the device so I would get better thermal conduction between the ic and the probe wall.

The end of the probe was sealed with 5 min epoxy and heat shrink tubing.
The airlock cap is a standard item purchased at any homebrew shop.

The end of the probe looks dirty, but it is just a shadow on the probe it is completely shiny and easy to clean with being stainless steel.

 

[tharding]

Here is a view of the inside where you can see the copper heat exchange coil.
The 6 gal carboy when placed inside the cooler left me with a 1/4 gap all around the carboy which allowed the placement of the heat exchange coil made from 1/4" copper tubing. The outside area the carboy is filled with water and provides a nice even temperature control of the wort inside the carboy.

 

[Nashbrewer]

Suscribed

 

[tharding]

Here is a pic of the heat exchange coil and the temperature probe.
The termperature probe was made from the 1/4" tubing with a end cap soldered
onto the tubing. When I get around to making a new heat exchange coil I think I will increase the number of loops. But for now this works great for fermenting ales.

 

[tharding]

Here is a pic of how the heat exchange coil wraps around the carboy inside the cooler.

Note: With this type of coil wrap, both ends exit the top of the cooler.

 

[tharding]

Nice! I had a similar idea but not using a fridge, just another cooler with an ice block in it. Too many projects going to actually build it at this time though.

The first version of the system I was also using a second cooler with water and ice. However it was a pain adding new ice every 24 hours.. With the kegerator I can set and forget...

 

[dbrewski]

Pretty ingenious use of the kegerator as coolant source, I did not catch that on first glance. It is amazing how inventive people are when there is beer involved!

 

[Homercidal]

The first version of the system I was also using a second cooler with water and ice. However it was a pain adding new ice every 24 hours.. With the kegerator I can set and forget...

I actually have 2 fridges as ferm chambers, so I don't have need for the other project, but it will be a nice thing for someone with not much room, or who doesn't have a kegerator.

Did you use an ice BLOCK for your first system? I haven't tried it, but I thought it might last more than 1 day... Especially if it were kept in a second cooler...

 

[tharding]

Yes, I used ice blocks from the freezer in the first system.. I changed them everyday so the water in the cooler would not get too warm. I wanted a nice temp differential for the water going through the heat exchanger. If the coolant got too warm the cycle time of the pump would increase.

 

[starman]

That looks slick. I'm anxiously awaiting more details on the hardware and software of the build.

 

[tharding]

This is a view of the corny key with the power cord, 2 tubing lines and the 1-wire temperature probe.

 

[tharding]

Here is a pic of the submersible pump that sits inside the keg.. It just fits through the hole in the top.. I bought it at a local big box store..

GeoGlobal Partners - MD11300

 

[tharding]

The 1-wire 110v switch, it socket can be turned on or off independant of each other. The submersible pump is plugged into the socket and switched on and off via the controlling software app.

 

[tharding]

The brains of the device.

 

[tharding]

The design goal was to be able to place everything inside of a standard 110 outlet box.

The 110v sockets are electrically isolated from the dc components by the use of 5v 110v relays. The power for the relays and the 1-wire ic is supplied by the 1-wire network which comes from the 1-wire controller. Therefore no 5v power supplied is needed on the board.

The DS2408 was placed on a daughter board since I don't have the capability to produce a 2 sided circuit board.

The internal fuses limit the amps for each socket to 5 amps.

 

[dbrewski]

wow...amazing, but you're way ahead of anything I could put together. This officially just became a project that I'll have to admire from the sidelines.

 

[tharding]

Thanks for the compliment.. Now remember there is always more than one way to skin a cat. Sorry cat lovers.

You can build a lot of this from off the self parts. I am just showing what I have done.
Hopefully this will spark someones creativity in putting together a system that has the same overall end result.

 

[kwarthe1]

That's a pretty clever setup! I agree there are many ways to skin that cat, but that is very cleanly done. Any chance you could put up that schematic? I'm venturing into pcb etching and this would be a great project to chip my teeth.

 

[tharding]

That's a pretty clever setup! I agree there are many ways to skin that cat, but that is very cleanly done. Any chance you could put up that schematic? I'm venturing into pcb etching and this would be a great project to chip my teeth.

Thanks, I sure can put up the schematic. I will need to clean it up a little, please give me a bit of time to do the cleanup.

I am using Eagle layout editor v5.11.0 which is a free download from the net.

 

[tharding]

wow...amazing, but you're way ahead of anything I could put together. This officially just became a project that I'll have to admire from the sidelines.

ok dbrewski, lets bring you back into the game. I totally forgot about my first versions of the system. In the first version before I developed the 1-wire 10v switch I was using x10 technology to switch the pump on and off.. I used my 1-wire temperature probes to tell the software when to issue the x10 commands to the x10 module which was controlling the pump. This still gives us a wireless connection between the host computer and the pump..

If you don't know about x10, it simply uses your house wiring to send commands to the different modules you have plugged into outlets. This allows you to computer control the pump, fan, light. Whatever you have plugged into the 110v x10 module.

This should bring you back into the game.

 

[tharding]

To utilize X10 in the system, you would need to buy a product called
ActiveHome PC Home Automation System, you can find it at a website called x10 dot com. This basic system gives you 1-3 prong appliance module(AM466), which would be used to control the pump.
It also gives you a module to allow you to interface the host computer to your house wiring and software which allows you to control the appliance module.

A driver is also free to download that allows any software application to send commands to an x10 module. I cant remember how I got the driver software, so I need to research this item.

Edit: For the x10 system you would need the ActiveHome Professional Home Automation Starter Kit with USB Computer Interface, Cable and Software - $50 (CM15A), download for free the ActiveHome Professional SDK, and buy a 3-prong appliance module(AM466) 14.00.

So for 64.00 you would have the necessary pieces.

Hopefully I haven't forgot anything. We can always work out the details before anyone goes out and buys x10 modules...

Summary: Note you can get the interface module(CM15A) and the Active Home Pro Software for 49.00 total.

Components Needed:
Active Home Pro Software
ActiveHome Professional Computer Interface and USB Cable(CM15A) 99.00
3-pin Appliance Module (AM466) - 13.99
Active Home Pro SDK - free

 

[tharding]

Here is the Bluetooth/1-wire adapter that the host system talks to.
This prototype consists of 2 modules a bluetooth module and a power supply/1-wire module.

The bluetooth module receives the 1-wire commands from the host computer. On this board you can see the bluetooth chip and 2 leds. The greenish led indicates the connection status with another bluetooth device and the red led indicates when data is flowing through the module. The bluetooth ic is from Roving networks RN-41. This module can be configured over the air. The bluetooth ic supplies TTL level signals which are passed to the 1-wire module. The bluetooth ic is a Class 1 device and capable of a 100meter range.. Now if you are trying to go through walls, the distance will be limited. So those with 5,000 sq ft homes this module may not cut the mustard, if you are going from one end of the home to the other end.

The 1-wire module performs two functions a power supply. Supplying 5v to the 1-wire network and 3.3v to the bluetooth module and a 1-wire interface. There is a LM3940 which supplies the 3.3v for the bluetooth module. There is also a DS2480B which is a serial port to 1-wire interface ic. It connects directly to the bluetooth module. The module also has a DS9503 an ESD protection device for 1-Wire interfaces.

The transistor(mosfet) sitting off by itself at the top of the picture was an additional mod I made to the system, where I can send the bluetooth module a command to toggle
one of its outputs which then grounds the VDD pin on the 1-wire interface chip. Basically giving me power reset capabilities if the 1-wire communications ever go haywire.

I know there won't be many of the members creating bluetooth/1-wire interface boards, but it is not necessary.

You can eliminate the bluetooth module completely. You just need to connect the 1-wire network directly into the host computer. I wanted a wireless solution so I could one day use the 1-wire setup to control my mashing process.. For fermenting, my kegerator and fermentor are in my office next to my computer, so if I wanted I could connect everything directly to the computer. We can explore this option later if others are interested.

 

[mxc1090]

tharding:

What process do you use to etch? (I use laser transfer/iron with muriatic acid and H2O2)

Does this connect directly to rs-232?

What are you using on the host computer to read the serial data?

Any fears of having AC and DC so close together in the same box (aside from being against electrical code)?


I do have one qualm with your setup: you are sending 5v through a phone line to the relays (>100mA a piece, correct?). I believe the only reason this works is because of the short length of the cable. If I had the 5V power supply on the other side of the room, it probably would drop the voltage too much, right?

I wouldn't be doing x-10, but I would have a spare laptop in the brew area and just wire everything up through that and then online. I have been going through an arduino for my 1-wire setup and reading the serial data in processing, but considering I can get the DS2480B as a free sample I might try it out.

Awesome setup. You MUST keep adding more things. Ever consider the cheap RF modules? http://www.sparkfun.com/products/9582

or hooking the output directly to a dd-wrt router with serial setup?

 

[spearko520]

This looks awesome! - i'm going to have to look into the one wire thing- i'm not sure but maybe it's similar to the 0-10 VDC that our ATC guys usually use for control circuits. I currently use a chilled glycol loop (the coil is in the freezer section of a refrigerator) and a pump to cool an insulated cabinet that houses kegs. A space temp controller currently maintains the temp, but I can kind of see an application here (using your ideas) for some additional controls and maybe an add on for more fermentation space... keep us posted and keep up the good work!!!

 

[dbrewski]

ok dbrewski, lets bring you back into the game. I totally forgot about my first versions of the system. In the first version before I developed the 1-wire 10v switch I was using x10 technology to switch the pump on and off.

X10 huh? I will look into this. I have a couple projects to finish up but thanks for the tip!

 

[tharding]

tharding:

What process do you use to etch? (I use laser transfer/iron with muriatic acid and H2O2)

I do the same. I have been using kodak high gloss photo paper for the printing medium. I want to try clear overhead projector film when I attempt to do a double sided board.

tharding:
Does this connect directly to rs-232?

Not sure what this is? If you are talking about the RN-41 bluetooth ic.. It does put out rs-232 formatted signal at TTL levels. You would need to add a RS-232 driver to connect to a RS-232 port

tharding:
What are you using on the host computer to read the serial data?

I am using maxims java 1-wire api library to communicate via the bluetooth serial port on the host computer.

tharding:
Any fears of having AC and DC so close together in the same box (aside from being against electrical code)?

No fears. Just lots of caution when working with 110v AC. Each socket is limited to 5A. The ground and neutral wires go directly to the sockets and the power line is switched by using mechanical relays. Of course the power module would probably not get a UL rating, but I am not looking at manufacturing them for resale and anyone building one does so at their own risk. I am sure the box could be redesigned to actually meet UL code standards. Again I consider the power box to be like a power supply module that plugs into the wall.

tharding:
I do have one qualm with your setup: you are sending 5v through a phone line to the relays (>100mA a piece, correct?). I believe the only reason this works is because of the short length of the cable. If I had the 5V power supply on the other side of the room, it probably would drop the voltage too much, right?

First the bluetooth module is meant to sit near the power module and the temp sensors not sitting across the room as that would defeat the purpose of eliminating the wire from the host computer to the bluetooth module.
Now lets explore the electrical aspects.
Cat 3 telephone cable contains AWG 24 solid wire which has a DC resistance of 0.0302 ohms per foot. If we had a length of cable 50' long, we would calculate the distance * 2 for the ground return, giving us a 100' length of AWG24.. which calculates out to 3.02 ohms. Now the relays I am using are 5v relays which operate at 89 ma each for a total of 178 ma if both are operated at the same time. Which would give us a voltage drop of
(v = IR) or 0.538v. So now my supply voltage is sitting at 4.5 v. still plenty of voltage left to operate the sensors and bluetooth module. The 1-wire sensor will operate down to a voltage of around 3.0v and the bluetooth ic likes 3.3v and the relays will operate down to 3.5 volts. So we could still operate everything at a distance of 50' axway from the power source.

tharding:
I wouldn't be doing x-10, but I would have a spare laptop in the brew area and just wire everything up through that and then online. I have been going through an arduino for my 1-wire setup and reading the serial data in processing, but considering I can get the DS2480B as a free sample I might try it out.

The point of the x10 module was to be able to remotely wirelessly control a 110v device from a computer. I accomplished this by building the power module, but those who don't have the skills to do circuit boards and want to buy an off the self product can use x10. I have in the past and it works just fine for turning the pump on and off.

Do you know of any 110v switching device that can be controlled by a computer program?

tharding:
Awesome setup. You MUST keep adding more things. Ever consider the cheap RF modules? http://www.sparkfun.com/products/9582

or hooking the output directly to a dd-wrt router with serial setup?

Thanks.. It is great posts like yours that make us think hard about our setups and if there is anything else we could do differently.

You know I haven't. Before the bluetooth idea, I connected the 1-wire network directly to the host computer and communicated with the sensors via the serial port, using maxim's serial port adapter. I wanted to get rid of the wire running across the room so I dreamed up the bluetooth/1-wire module to eliminate the connection to the host computer. The 1-wire adapter also did not supply 5v to the network. By using bluetooth and its virtual serial port mode SPP I did not have to make a single change to the controlling software.

 

[tharding]

I currently use a chilled glycol loop (the coil is in the freezer section of a refrigerator) and a pump to cool an insulated cabinet that houses kegs.

chilled glycol loop.. Sounds interesting.. I could eliminate the keg of water in the kegerator to make room for another keg of beer..

I can see copper tubing pressed against the cooler plate in the back of the kegerator cooling the glycol and an inline pump cycling the glycol through the system.

Maybe this will be a new mod in the future. At least I now know someone to hit up for info on using/where to buy glycol.

 

[mxc1090]

First the bluetooth module is meant to sit near the power module and the temp sensors not sitting across the room as that would defeat the purpose of eliminating the wire from the host computer to the bluetooth module.
Now lets explore the electrical aspects.
Cat 3 telephone cable contains AWG 24 solid wire which has a DC resistance of 0.0302 ohms per foot. If we had a length of cable 50' long, we would calculate the distance * 2 for the ground return, giving us a 100' length of AWG24.. which calculates out to 3.02 ohms. Now the relays I am using are 5v relays which operate at 89 ma each for a total of 178 ma if both are operated at the same time. Which would give us a voltage drop of
(v = IR) or 0.538v. So now my supply voltage is sitting at 4.5 v. still plenty of voltage left to operate the sensors and bluetooth module. The 1-wire sensor will operate down to a voltage of around 3.0v and the bluetooth ic likes 3.3v and the relays will operate down to 3.5 volts. So we could still operate everything at a distance of 50' axway from the power source.

RIght. After looking at the spec sheet for my 10A 5V relay, I noticed a minimum 'turn-on' value around 3V

Do you know of any 110v switching device that can be controlled by a computer program?

Not off the top of my head, but I could probably figure out how to make one with tan arduino + processing (kind of the only programming I know)

Thanks.. It is great posts like yours that make us think hard about our setups and if there is anything else we could do differently.

Cheers to you for starting the discussion!

 

[tharding]

Not off the top of my head, but I could probably figure out how to make one with tan arduino + processing (kind of the only programming I know)

I like to program pic microcontrollers using a product called JuneBug and Microchip MPLab IDE.

When developing the 110v controller I thought that a microcontroller was not the way to go and 1-wire was a better fit with a software program polling the sensors and activating the 110v module.

Now if I was going with a dedicated controller panel, it probably would have several microcontrollers all communicating with each other.

So many different ways to slice an apple..