Climate Control

**Cocide** · 04-03-2008, 09:37 PM

This might seem like a dumb question, but I noticed in the computing 101 it mentioned that car climate control was possible. Is that easy to accomplish (only 1 or 2 pci cards need to be made and software is available)?

I am preparing to build a carpc... well sort of, originally I was going to build a low power, low cost, distributed computer system and program the whole thing up in assembly. Mostly because I live in Texas and would have liked to put in in my trunk (heat) and the microcontroller system would have used VERY little power and produced almost no heat.

The things that it MUST do are:

Digital media playback
Ipod interface
Sirus interface
Climate control
GPS
WiFi network creation / expansion / connection

and it would be nice to have:

RFID tag readers
Lock / trunk release on RFID scan
Start car after PIN entered or RFID scanned
Window control
Hydra ECU interface

Currently I have a small system that can control locks/windows, read RFID tags, start the car, HDD and usb file reading (almost music playback), GPS (no nav), climate control, and basic ethernet networking. The VGA output is killing me so I decided to look into a full on pc.

Long story short, I have that small system that I can use, but do not have to. How would I go about either interfacing the pc w/ the system I built, or how would I make a carpc that dose all of the tasks (RFID locks would still be micorcontroller based so when the car is asleep I can unlock the doors). Mostly what OS (I know my way around linux and mac, very little windows) would give a good looking interface, let me do climate and window control, and still allow low overhead, also what hardware would I need to look into / build to make it work.

The car is a 96 Mazda Miata, I plan on removing the climate control cluster and the radio to fit a 8" or 8.4" 4:3 display. I am going to try some homebrew transreflective mods and will end up making a LED backlight that auto dims. For the pc processor I have a 2.4ghz core2 duo T7700 (socket P I think) laying around w/o mobo, ram, ect. I end result need 5 channels of audio (LF RF, LR RR. Sub).

Any help, with the carpc solution or where to look to get a new/better idea for generating a VGA output for the microcontroller system, would be greatly appreciated.

O and has anyone used a VM84 or VM80?

**stonestatue** · 04-04-2008, 01:38 AM

Climate control is possible with your car PC. Basically you send a signal from your carputer to a relay that closes a circuit which activates a motor or a switch.

Do a search for Fusion Brain. It's really good for climate control.

**Cocide** · 04-04-2008, 01:51 AM

That is absolutely exactly what I need, but will any of the frontends play nice with it or will it be a program I call up?

**stonestatue** · 04-04-2008, 01:32 PM

Road Runner is pretty customizable, and best of all, it's free. You might need to do some skin editing, but the Digital FX 3.0 skin is pretty easy to customize from what I have seen.

**Cocide** · 04-04-2008, 02:53 PM

Thanks alot, thats a great starting point.

Now all I have left to do is buy most of everything, fit the servos / relays / RFID readers / power lock solonids / power window motors, wire it all up, make the software work, get the RFID tag implanted in my hand (yes I know its risky, its not just for my car, I wont change my mind), fit the lcd, mount the pc and ecu, and put the interior back in.......

Its gonna be a while yet, but thanks alot

**stonestatue** · 04-04-2008, 08:55 PM

I have just as much, if not more, to do as you. Cost is the main factor, with time a close second.

Ask h3rk, he knows a lot about automatic climate control. I believe he is working on something to integrate with Fusion Brain.

**inh** · 04-05-2008, 02:33 AM

Automatic climate control will have to wait for now, unless the Brain guys added some stuff in their software to automatically control outputs based on inputs. You can hook the brain up though, and use the software (skinned to work nicely in roadrunner, of course) to manually control it. That is what I will be doing.

**2k1Toaster** · 04-05-2008, 02:43 AM

Originally Posted by inh

Automatic climate control will have to wait for now, unless the Brain guys added some stuff in their software to automatically control outputs based on inputs. You can hook the brain up though, and use the software (skinned to work nicely in roadrunner, of course) to manually control it. That is what I will be doing.

This has been done and available since Uber was released.

Climate control is doable. How easy depends on your car. If it is servo based, then you will need another servo control board from Fusion Brain to wires. Since you are electronically inclined it seems, it should be rather easy for you.

**Cocide** · 04-05-2008, 05:02 AM

I guess this is where I would need to provide more information about my install plans. My biggest concern with running the climate off of a pc is if the pc is, for whatever reason, not functioning correctly or at all.

Having an easy way to interface a frontend with digital outputs is almost all I need.

At this point it seems to me that my best solution is to write my own code on a microcontroller that will control the elements of the system. all I want is to get the ability to have temporary push buttons on the pc that raise and lower the target temp (two separate outputs), the ability to override the system and do manual control (override pin then pins to turn zones on or off) based on latching buttons, and control of mixer and blower (four more temporary pins).

Is the Brain is able to pulse outputs so I could make a basic instruction system and do it all over one pin?

That way I could have the Brain connect to my system, that will automate, and allow it to on the fly modify.

I have found several posts or topics that by h3rk has commented on, most of which have drastically changed my concept of how to automate the system effectively.

Using a Brain would I be able to script actions such as:
if inputX high
call up a keypad
get value
compare to variable / file
if input == constant
set outputY high
wait [time]
set outY low

Basically if prompted allow me to enter a pin number then start the car.

If it is not obvious that am stuck in my view that it is prone to failure and I could find better low power solutions. Don't take me wrong, I do like the idea of a computer in the car, in fact thats the idea I started with a few months ago. Unfortunately I have been unable to generate a VGA signal grater then 640x480 with 18bit color easily, not to add that did not look anywhere as nice as some of the interfaces do and would be difficult to say the least to code a good interface into the system.

Well back to topi.... closer to topic.

The Brain looks like exactly what I need, is it linux compatible? Dose it allow for data transfer (even slow, I'm talking just if pressed send 00110101 then low)? Can a command force some part of the fronted to focus to do its job (the whole keypad thing)?

Thanks again for the help and advice

**Cocide** · 04-07-2008, 12:14 PM

Well I have managed to answer all of the above questions to my satisfaction. The only thing that is left is how to control the blower motor. Would it be a good idea to do a PWM system for it (rapidly turning the motor on and off, longer time off vs time on makes it slower) or will that cause excessive wear on the motor? If a PWM system will not work then what should I use to change the speed?