car ac control integration

**2nau-t** · 08-29-2004, 10:11 PM

hello this is my first post to mp3car.com
my question is I would like to use the serial port or parralell port of my carputer to control my ac in my 98 dodge neon I am currently using a serial relay unit for the blower motor and floor to defrost switch but i have 2 rods that do the temp and inside outside air flaps. i have looked into stepper motors but am not familliar with there programing. could someone help me with this if i can get rid of the ac control knobs i can upgrade to 10.4 lcd touchscreen thank you dave

sorry to make a new thread but did not find another to attach to

**ppgt94** · 08-29-2004, 10:20 PM

You already have it setup so you can control fan speed through PC via serial?

**brooksware2000** · 08-29-2004, 10:35 PM

Here you go:

http://www.parallax.com/dl/docs/books/sw/exp/sw26.pdf

**2nau-t** · 08-29-2004, 10:46 PM

yes i have the fan speed and blower motor controled because in neons it is controled as a switch and all you have to do is setup a serial port relay here is the one i used
http://www.audon.co.uk/som1.html
linked with profit lab software http://www.audon.co.uk/profilab.html
it is easy to make a grafical interface it doesn't look cool but i am working on that
thanks brooksware

**droswell** · 08-30-2004, 12:28 AM

Instead of a stepper motor turning mechanical knobs, how about bypassing that? Just a thought ...

If they are potentiometers you can build circuits to emulate the resistance that turning the knob would do. If they are switches, you can build relay circuits that will operate pretty much the same way. Less to go wrong.

**2nau-t** · 08-30-2004, 01:35 AM

the blower and the selector for floor,vent,head,and defrost are switches the hot,cold and fresh,recirculate selector is a real mechanical element that is connected to a flap I would need a stepper motor or liniear motor or something to push=pull to give the desired effect I thought stepper motor would be best because i could not only select hot,cold but a thousand other variations in between the fresh-recirculate could be driven linearly because it is either one or the other. i am researching the stepper motor info that was given above but does anyone else have an idea about another form of control

**frodobaggins** · 08-30-2004, 02:29 AM

Originally Posted by 2nau-t

Does anyone else have an idea about another form of control ?

Servos if you can find them powerful enough.

**pioneer** · 08-30-2004, 02:50 AM

Yeah, servos. They take up less power to operate than stepper motors and they are cheep as chips.
Also, they are very precise. You can set them to the same position over and over and they will not fault.
Stepper motors on the other hand need an encoder on them so you can work out there position, else you might end up breaking something.