HVAC Control on Car PC through Serial Port.

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Originally Posted by J's89

My system uses vacuum to control the air direction ( defrost, vent, floor, ect.) This is done manually by diverting the air via the switch. The temp control is handled by a cable routed to a door that either circulates the air over the heater core, or bypasses it. Most Fords with knob AC controls are done this way. Is there any way to address this? What would be required to retrofit? I've been all through my interior, but have no knowledge of newer electronically controlled systems.

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With that type of system, you may be able to integrate a linear actuator into the system, to pull and push the cable. Not sure how much force you will need, or the amnount of travel, but I am thinking that the travel shouldn't be all that much because it is the know moving the cable. I bet the max movement is a couple of inches. An actuator should easily be able to handle that. As far as strength, that might be a matter of trial and error. I will warn you though, most actuators you will find will be gib bucks, say in the 200 dollar range although you may be able to get one cheaper.

Integrating it with the Mastero device shouldn't be too hard. Would just need to add a relay or two. Maybe Mastero can chime in on that.

Michael

a servo would be so much easier to use than a linear actuator

Any pics for this?

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Originally Posted by Mastero

Hmm well i am not aware of the vacuum system ..... my ride is a 1994 Mercedes C250 D and it has system like this.

If you have any info on the vacuum system it shall be good for reference.

Mastero

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There is one vacuum line from the engine bay that supplies vacuum to either a four or five way connection on the back of the control cluster. Rotating the switch supplies vacuum to the desired combination of vents, defroster, floor, etc. The other end of the vacuum line connects to a diaphram "actuator", or motor whichever is the correct term. It in turn raises or lowers rotating lever that extends out of the sealed evaporator core box which is attached to the door that directs the internal air flow of the system. Did any of that makes sense? I'd really like to do this. However, a $200 actuator to get the job done is out of the question!
Mainly because I have to first buy another AC system to install... I deleted it so I could go fast. It was a brilliant decision...I should have slept in that day. :shiver:

Quote:The blower always has three wires for speed 1 ~2 ~3 when you touch these wire to +12v the blower goes on the desired speed.

I think thats an over simplification. some use series /parallel wiring of the resistors via a funky switch to get the various speeds.

I know with my truck, it wasnt as simple as that.

I am really interested in this project, and I know you do great things, but what about heat? Where I live, we have hot summers and cold winters, so I need heat and air conditioning. It sounds to me like you can't control the temperature beyond making it cooler with the AC

Quote:

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Originally Posted by J's89

There is one vacuum line from the engine bay that supplies vacuum to either a four or five way connection on the back of the control cluster. Rotating the switch supplies vacuum to the desired combination of vents, defroster, floor, etc. The other end of the vacuum line connects to a diaphram "actuator", or motor whichever is the correct term. It in turn raises or lowers rotating lever that extends out of the sealed evaporator core box which is attached to the door that directs the internal air flow of the system. Did any of that makes sense? I'd really like to do this. However, a $200 actuator to get the job done is out of the question!
Mainly because I have to first buy another AC system to install... I deleted it so I could go fast. It was a brilliant decision...I should have slept in that day. :shiver:

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yea, i know what your talking about...I'm a Ford man...One way to do would be to get a couple of solionds that could control the vacuum just as the switch did but give you a way to control it...wouldn't be that hard :confused: ...you would just have to find the correct valve layout...

Out of interest, did you designed the hw yourself.

From the look of the PCB it didnt look like homebrew to me, more like a mass produced board already.

I see it has an IR remote sensor. Do you have a pic for the remote handset?

I have a ford too and attest to the vaccum switch. but i think what the purpose of the project is a bit more basic then total HVAC controlls.