A carputer for controlling HU only?

TheLTC · 12-27-2005, 06:16 PM

I am wondering if there is any resource base for making a carputer with nearly its sole purpose being to control a HU. I am somewhat of an audiophile, and thus I have a hard time parting with my high end HU for SQ reasons. I also like to listen to my stereo from outside of my car. I am already in the process of working on fabbing a remote using 2x RFPIC (one in remote, one at base) to control my HU. I have previously found info with incomplete instruction sets for various HU link systems (ipbus, unilink, etc).

So, anyone have thoughts/advice?

Thanks in advance.

custardbomb · 12-27-2005, 06:40 PM

If you search, I know for an Alpine headunit there is a pcb that someone on here has developed that hooks into the bus that allows control of the hu from a pc, I am unaware as to any other head units though.

SnyperBob · 12-27-2005, 06:44 PM

This question has come up a couple times recently. While I haven't come across anyone working on a direct solution for this, I do think it's possible.

jbors is a member here that developed the car2pc adaptors. Basically an adaptor that plugs into certain car stock head units where the stock CD player would plug in. When you push the buttons on the head unit it intercepts those buttons, sends it via USB to the computer, and his software/drivers allow you to set your carputer up so it'll change songs and whatnot in your frontend.

Basically you're trying to do the opposite, from the carputer to the headunit. You may want to try contacting jbors and ask him some of your questions. He's already figured out some of the communication stuff between (stock) head units. After he's finished designing some his car2pc adaptors to work with more models of cars, he may be interested in looking towards what you are asking about.

Then again, this may be super complicated and not feasible. I could only imagine how different each model aftermarket head unit might be, which would cause some huge problems.

Hopefully some discussion will get the wheels turning.

There is a guy from Europe on here that has a thread talking about controlling a head unit. He's designing it for a specific head unit from some type of car that's common in Europe. Once his project is complete, he's planning on selling his software/drivers with one of these head units. It's not a super high quality one like I'm sure you have, but it's a step in the direction. Be sure to check out his thread.

I can't remember his name, anyone have time to search for the link and post it in here?

TheLTC · 12-27-2005, 06:51 PM

Yeah I saw that thread, an ALFA or some car. And yes, the instructions sets are super-complicated for some of these (site I had for Sony Uni-link on my old pc had instruction set that printed out 60 pages).

I will talk to jbors. I am an EE student, so I have some idea what I am doing, but I have never setup stuff on my own to try to reverse engineer something, so that is where I guess I don't know where to start.

Thanks for the responses guys. Much appreciated.

turbocad6 · 12-27-2005, 07:10 PM

the easy way to do this is to have the pc interface with a remote that controls the head unit, if you have a comprehensive remote this is a practical way of doing this.......

another possibilty is a head unit with a wired remote input could probably be controlled through that easily enough.... may require girder among other things..., but to try to have full control through something like an ai-net buss or something would be almost impossible I think..... if not impossible, then at least highly improbable

TheLTC · 12-27-2005, 07:26 PM

My problem is that standard remotes (especially IR, I hate IR remotes in a car, how useless) lack any amount of functionality that I desire. That said, I guess I dont really know if anyone out there makes a significantlly advanced car audio remote.

Sidebar - In terms of complexity, my remote would include a 4" touchscreen LCD, driven by an as of yet undetermined second PIC chip. I have already comped some of the chips that I need, and my university has all of the programming hardware that I need, so I just need to figure out the details.

turbocad6 · 12-27-2005, 07:37 PM

what exactly are you looking to control?

TheLTC · 12-27-2005, 07:42 PM

Everything possible. I plan on extending it beyond the HU, but that is the hardest part to setup.

turbocad6 · 12-27-2005, 07:43 PM

you can also have a ir control signal feed into an ir reciever through a fiber optic line, it would be almost like hardwired as the whole thing could be hidden....

I have an alpine system & my remote can control anything & everything, from nav to processor & everything inbetween.... switch different screen outputs on aux screens, tracks, discs... everything really... I could see trying to control the head unit this way through a pc, although I wouldn't ever do it....

TheLTC · 12-27-2005, 07:50 PM

hmm, that is an interesting thought, but I would still have to know what to feed over the IR xmitter.

turbocad6 · 12-27-2005, 07:55 PM

look at irman I think it is, check out girder & reserach ir controls through pc....... there are other ways of teaching commands.... universal remotes work on this premise... I think this is the most practical aproach & shouldn't be very difficult.... hacking a buss can be futile, as a head unit isn't expecting core function controls for the head over it... I doubt it can be done at all really....

TheLTC · 12-27-2005, 08:02 PM

Well for things like the Sony Unilink, the steering column wired remote is connected into the unilink connector. It turns out that the connector can be used to do tons on the HU. I just need to figure out if this is similar to other brands. I would think that it is, as it would give service centers a quick and easy access to running diagnostics on HU's.

turbocad6 · 12-27-2005, 08:18 PM

the remotes I've seen go to a seperate plug for them, I never seen a remote interface like that, but haven't screwed with sonys in a long time.... if what your talking about exists, that would be where to start... the switches probably only vary resistance & then the interface box transfers these signals to data... the easy way is the keep the interface box & interface with varing resistances from the pc controlled through a relay board or something.... or I guess you could try to anaiize & decipher the data

way beyond me... I'd interface ir/ir through fiber optics, gotta be the most practical.... & this would also be highly expandable..... making fiber optic switches & y adaptors is always fun

I know alpine has nothing like your talking about for ai-net.... what other high end head uses a data buss remote control...I wouldn't think any, but if sony does through uni-link that might just be what you are looking for...

TheLTC · 12-27-2005, 09:24 PM

I finally found my old site about unilink.

http://www.mictronics.de/unilink_resource.php

BTW, AI-Net is based on the m-bus protocol and can be used like I am talking about, but I want to know more about ip-bus and other lesser mainstream brands.

turbocad6 · 12-27-2005, 10:31 PM

wooh, that's some pretty intense stuff.... good luck with it....