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hacking car hvac

PostPosted: April 20th, 2015, 9:16 am
by seatibizacupra
My car has a hvac control and I wish to fit a andriod nexus 7 where the hvac display currently is.

It uses analog buttons which join up to a micro controller and from there the controller send the information to a climate control module.

What would be the best way to go about this project.

Cheers leigh. I have pdf files of the current hvac system.

Re: hacking car hvac

PostPosted: April 22nd, 2015, 5:56 am
by st2000
How old is your car?? Mine is half a dozen years and it's heating and air conditioning panel is connected using just a couple of wires. Clearly (I have assumed) it's got to be some sort of serial bus.

If you got a bunch of switches to emulate and you want to control them from an Android, I would start by looking at an IOIO board. Supposedly, if you can program an Android and understand just the basics of the PIC processor on the IOIO board, it easy to develop a program to control low voltage / low current loads. But it's likely you will have to build upon the IOIO board design to interface with heavy loads like a solenoid.

Re: hacking car hvac

PostPosted: April 22nd, 2015, 6:18 pm
by Osgeld
my half dozen year old (CHEAP) car is still running all the power though the controls, but a lot do use either CAN or LIN buss which are serial and lots of micros's come with it on board, if you look for it

Re: hacking car hvac

PostPosted: April 23rd, 2015, 10:40 am
by seatibizacupra
Cheers guys. my car Is 2000 reg so just as can bus system where making there way into cars.

The two wires which come out of the back of my radio/hvac control which lead down to the climate control module(j255) and called Kilma bus in and Klima bus out.
Image

And here is it joined up to the j255 module which acutaly controls the hvac and does all the clever stuff.

My rado/hvac display is just for displaying the info and allowing my input into the j255 module.
Image

Here you can see the two wires which join up to the j255 and these are the wires I'm hoping I can just send the same information as the current radio/hvac when I press the buttons etc.

You mention ioio mite look into that as I belive that's mite make the display side on the tablet easier as it's andriod based.

Re: hacking car hvac

PostPosted: April 24th, 2015, 6:26 am
by st2000
@seatibizacupra, I thought you were replacing a simple interface. Something you might even be able to backwards engineer through inspection only. This control panel appears to have a VFD with dozens of elements, numerous buttons and a PCB with lots of parts which probably includes a processor or custom chip. It just sounds like a big chunk of work. And will likely take so long that you will be out a climate control panel for some time.

Instead, research if there really is a serial communication bus and see if there is enough information on the net so that you can backwards engineer that. Then I would just tap into it. That is, just display the settings. Even that may be a big task. But, at least, you will not be w/o your control panel during your development cycle.

Do take care you are not compromising any safety features. I am assuming these controls are isolated from safety features. But that is just a guess.

Re: hacking car hvac

PostPosted: April 25th, 2015, 5:05 am
by seatibizacupra
I no it won't be easy.

the system it's self is based on the same as a mk4 golf but in the mk4 it's all a self contained unit and control module. In my car they split the system into ye radio/controls which the send the data to the module.

The main radio board is quite big but this controls everything from radio. Tape player. Cd changer. And the hvac inputs. Which is then sent down to the module.

I have found he main micro controller on this board.

Re: hacking car hvac

PostPosted: April 25th, 2015, 5:08 am
by seatibizacupra
Also no safety features the screen also displays mpg miles to empty etc but this can easily be moved by fitting a set of golf clocks where this information is displayed.

Re: hacking car hvac

PostPosted: July 18th, 2016, 8:16 am
by lucas147
seatibizacupra wrote:My car has a portland hvac control and I wish to fit a andriod nexus 7 where the hvac display currently is.

It uses analog buttons which join up to a micro controller and from there the controller send the information to a climate control module.

What would be the best way to go about this project.

Cheers leigh. I have pdf files of the current hvac system.



I suggest you one thing hire a professional to do that job.

Re: hacking car hvac

PostPosted: August 8th, 2016, 2:15 am
by hanible147
seatibizacupra wrote:My car has a hvac repair Portland control and I wish to fit a andriod nexus 7 where the hvac display currently is.

It uses analog buttons which join up to a micro controller and from there the controller send the information to a climate control module.

What would be the best way to go about this project.

Cheers leigh. I have pdf files of the current hvac system.


I don't know about that if this type of thing is happen. I will definitely try this out. I have one query can i control my home and office hvac together with my ipad.