Building a TeensyPi controller for a fermenter and I'm totally new to this

[JakeRidesAgain]

Okay, so I've been working on building one of these. Anything worth doing is worth doing right, so I figured I'd get a networked RPi controller to do all my fermentation so I could just change things from remote computers/my phone and show off and be all cool and stuff.

However, this is my introduction into the world of Raspberry Pi, Ardunio, etc etc. I'm still trying to wrap my head around things. I decided to do a TeensyPi because it supports control for multiple zones and pretty much does what I need it do do. I'm running into some really basic questions I need answered though.

1) My cooling will be done by 12v muffin fans. I'm running 2 fans on each side of the fermentation chamber, one input and one output, to pull cold air from the chest freezer (where my kegs will be.) What I'm wondering is what I need to power the fans. I was looking at this, a 120v to 12v 10a power supply. Would I just wire that to some solid state relays, to the DS2402 switches, or to the fans themselves? Wiring is really where most of my questions are. I'm still learning how to read wiring diagrams, so like I said, most of these questions are probably pretty basic.

2) The power supply recommended on the TeensyPi site is said to be "5vdc power supply capable of delivering at least 1 amp, 2 amps or more are probably preferable." He says he picked his up on ebay, but that (like it usually does in ebay searches) gives me back a myriad of options, so that part wasn't entirely clear. This is what I assume he's referencing, but I just needed to confirm. I'm guessing this just runs off a wall outlet, which would in turn feed into the TeensyPi board in some fashion? Reading the wiring instructions, it wasn't exactly clear what this power supply was for (unless it was for running the switches/relays?)

3) Is there any recommended reading on this stuff you guys can suggest? I've got a few beginner level Ardunio books, but I don't know a lot about wiring this stuff, so if you've got any suggestions on reading for dummies/laymen, I'd really appreciate it.

Thanks guys. Reading this board has been a HUGE help during this journey.

 

[jimmayhugh]

1A) A 12v / 10a powersupply would be WAY overkill for a couple of fans rated at 350ma each. A 12v wall wart rated at 1.5a would be sufficient, with a large margin of error. This one would probably suffice AND power the TeensyPi.

Another option would be to use 120VAC Fans, which could be controlled by the DS2406+ chip and a SSR.

A third option would be to use an SSR to control the Wall Wart that powers the fan, an use a DS2406+ to control the SSR.


1B) The 12VDC fans' power requirements exceed the current limits that the DS2406+ chip can handle, so you'd need some device that could be controlled by the DS2406+, and has a larger power rating. The SSR's that I mention would not work, as they are AC controllers, and need a zero-crossing on the AC side to activate. You'd need a circuit similar to the one I use to power the LEDs on my SwitchBoard, but replace the 2n3906 with a beefier transistor, or a P-channel MosFET . Maybe that's another board I need to work on.

2) That is precisely the one I've got, just make sure that it's rated to work with 110VAC.

3) Sorry, not much help there. I've been doing this kind of thing for a LONG time, so I don't have much info on beginner books.

Hope this helps.

 

[JakeRidesAgain]

Hey, you found me! Thanks again for your help. If the way I've been bugging Mylo (the guy who built the original MOAFC) is any indicator, I might be bugging the snot out of you more once I get to that stage. At this point, everything is still under construction, so I'll let you know in the main thread if I run into anymore problems.

You mentioned that the fans could be controlled by using a wall wart, and that I could rig the SSR to control the wall wart, which would be switched by the DS2406+. Would I wire that to an outlet (which is what I did with my temp controller) and then plug the wall warts into that?

I may go with the 120VAC fans, thanks for the suggestion. I've found a few good deals, but I'm not entirely ready to pull the trigger just yet. I figure if I don't use these 4, I'll eventually find some use for them (like in an actual computer). I'm guessing wiring these would just be running the SSR between the fan and the power source, right?

Edit: So I found this page where a guy uses a DS2406 to control the on-off side of a power outlet. I think he's running the relay through a phone jack, which connects to the switch, which connects to (I'm assuming) some sort of Arduino-type device. So in place of the phone jack, if I just ran two different relays to the TeensyPi via the DS2406+ switch, would that work? Then, buy two different wall-warts to power the fans, which would come on when the switch tripped the relay. I would probably go aheady and put another outlet on there to power the TeensyPi, which would be always on, though I'm honestly considering rigging up some lighting as well. I've got a tenuous grasp of how this is supposed to work, but from what I've read it looks like this could work, unless my numbers are all wrong. I was also thinking of maybe doing 4 outlets, with two going to brew belts, which would give me heating capabilities as well. I doubt it will ever get too cold in my place, since the girlfriend is nice enough to let me have the fermenter inside, but I figured it'd be nice to have the option. Then another outlet to power the TeensyPi.

Edit2: Okay, I'm a bit like a man possessed today. I found this relay board, which looks like it would work. I'm really just leaving it here in case anyone is attempting the same process.

 

[jimmayhugh]

You're going to need 1 DS2406+ and SSR per outlet. My will handle up to 4 SSRs.

You'd wire the DS2406+ switches like this and then wire the hot side of the 120VAC to the SSR and outlet:

You'd then plug a fan, heater, pump, whatever into the receptacle.

 

[JakeRidesAgain]

Perfect. Exactly what I was thinking. Thanks again, Jimmy.