DIGITAL car A/C unit control - Page 2

Mañana · 08-22-2005, 04:23 PM

suppose you mean something like this?

warewolf · 08-22-2005, 04:27 PM

Quote: Originally Posted by Mañana

suppose you mean something like this?

Similar, yes with a LCD display and again, probally about the same height. My car is a 2001 Toyota Camry, XLE. Those look like they came out of a VW? I'm thinking that since it's possible to perform diagnostics via the HVAC control unit that I shouldn't rip it apart -- in case I need to read diagnostic codes off the LCD. I'm guessing the brains that actually perform the diagnostics are built into the control unit itself, and not in the rest of the car. Atleast, that's the impression I get from various wiring diagrams.

Mañana · 08-22-2005, 04:43 PM

Quote: Originally Posted by warewolf

Similar, yes with a LCD display and again, probally about the same height. My car is a 2001 Toyota Camry, XLE. Those look like they came out of a VW? I'm thinking that since it's possible to perform diagnostics via the HVAC control unit that I shouldn't rip it apart -- in case I need to read diagnostic codes off the LCD. I'm guessing the brains that actually perform the diagnostics are built into the control unit itself, and not in the rest of the car. Atleast, that's the impression I get from various wiring diagrams.

Yes, its from a VW

I havent ripped mine apart, but i will most likely do so within a few months... And, if it is not far to advanced like u'rs seems to be, try to control it via relay controls.

0l33l · 08-23-2005, 03:22 AM

My grandpa is working on a digital A/C control unit. Everything will be optoisolated, and it will have a A/D converter with a few inputs.

warewolf · 08-23-2005, 04:02 AM

Quote: Originally Posted by 0l33l

My grandpa is working on a digital A/C control unit. Everything will be optoisolated, and it will have a A/D converter with a few inputs.

Awesome, because all the research I've been doing on how my A/C control unit works it is beginning to look more and more like the "diagnostics" are just measurements of voltage or resistance on some of the leads. Everything else is servos, and feeding the appropriate voltage to things. So it might not be as bad as I thought. There's a separate Electronic Control Module for the A/C. Any ETA on when your grandpa will be finished? I'm probally going to be spending some more time (and money) on figuring out how the A/C control unit works.

Suprising thing: my daytime-running-lights sensor is tied into the A/C control unit! Talk about an obscure place. Control your headlights .. through your A/C control unit!

0l33l · 08-23-2005, 04:06 AM

Quote: Originally Posted by warewolf

Awesome, because all the research I've been doing on how my A/C control unit works it is beginning to look more and more like the "diagnostics" are just measurements of voltage or resistance on some of the leads. Everything else is servos, and feeding the appropriate voltage to things. So it might not be as bad as I thought. There's a separate Electronic Control Module for the A/C. Any ETA on when your grandpa will be finished? I'm probally going to be spending some more time (and money) on figuring out how the A/C control unit works.

Suprising thing: my daytime-running-lights sensor is tied into the A/C control unit! Talk about an obscure place. Control your headlights .. through your A/C control unit!

Ummm... well.... I really don't know.
Its not going to be a separate unit, because we are trying to make htis universal. So you'd have to hide your AC somewere else, and just hack up the front panel buttons. Check out my project thread, you'd find it interesting ,as I posted the diagrams for my AC.

inniss777 · 08-28-2005, 12:30 PM

Quote: Originally Posted by 0l33l

Ummm... well.... I really don't know.
Its not going to be a separate unit, because we are trying to make htis universal. So you'd have to hide your AC somewere else, and just hack up the front panel buttons. Check out my project thread, you'd find it interesting ,as I posted the diagrams for my AC.

Where are you thread is the info on the a/c?

0l33l · 08-28-2005, 06:18 PM

Quote: Originally Posted by inniss777

Where are you thread is the info on the a/c?

Don't have one. My grandpa is still in the designing stages

If you're asking about my A/C diagrams, then they are in my project thread. Click on the SC300 in my sig.

BTW: Your install rocks

Marinor · 02-17-2006, 06:31 PM

I know this is an old thread, but i was wondering if anyone figured this out?

I have an idea of using a digital screen to view the temperature, fan speeds, and what not.

But if this is still something that many people are working out, i might just stick with the dials idea.

warewolf · 02-17-2006, 08:07 PM

Quote: Originally Posted by Marinor

I know this is an old thread, but i was wondering if anyone figured this out?

I have an idea of using a digital screen to view the temperature, fan speeds, and what not.

But if this is still something that many people are working out, i might just stick with the dials idea.

Whelp, I havn't gotten very far (work has been kicking my ***) but I was able to log into a couple websites online that have wiring diagrams for the AC unit in my car, so I know exactly what wire goes where, and I have a guestimate at how to drive the stuff. So I need to magically learn some EE skills, and make something that will drive it via software

SO

Any Electrical Engineers on board?

Marinor · 02-17-2006, 08:11 PM

Any at all...hey another feature that you guys should think of...

Its a streatch but i think it would look awesome. A touch screen the size of a normal dash, but the back would light up like green or blue and the rest black. When you touch the screen or turn the car on it turns on and its a touch screen so that way you can control it.

I would design it and all but i don't know anything or where to start for something like that.

scott_fx · 02-17-2006, 08:18 PM

Quote: Originally Posted by Marinor

Any at all...hey another feature that you guys should think of...

Its a streatch but i think it would look awesome. A touch screen the size of a normal dash, but the back would light up like green or blue and the rest black. When you touch the screen or turn the car on it turns on and its a touch screen so that way you can control it.

I would design it and all but i don't know anything or where to start for something like that.

sounds like a skinned obd-11 program with dual displays (to fill up the space)...sorta

Marinor · 02-17-2006, 08:49 PM

Um...alright i only now have 3 posts and i have no idea what you just said there.

And probably

Dopefish · 03-01-2006, 03:06 PM

Can you post any images of the system, both the front-end and the rear connection points? Also could you post the pin-outs? I imagine your system operates mostly via a single serial databus like GM does however the additional outputs are for temp reading and servo control (directing air to cool effectively).

My idea to convert my car to digital A/C (since only the J-spec models offered it) is to bring the inputs from the HVAC to a serial port and control each function by a simple VB program. The only variable resistance circuits are the fan speed and temp setting which are both rheostat. For the fan speed I'd have a digital rheostat and up/down buttons in the GUI to control the speed, then have the VB program query the temp probe and match whatever temp I've requested at that time. It is much simpler than a factory system and would negate modifying the ducts.

While it may not be as effeciant it will definately do the job. I'm sure I could add in a feature to automatically turn down the fans once it has reached a desired temp range and turn them up accordingly as it moved away from the designated temp I requested.

Your system will be tougher since it is already digital and wil be requesting propriatary signals and additional controls. The voltages and signals you could probably back-probe for differant situations to see what and how it is effected. It'd take a lot of studying but I imagine you could cross-referance all the differant voltage outputs and make a VB program that could replicate those voltages and 'spoof' its functions.

~Kris