Carputer Idea

[Christopher]

I have an idea of using a mac mini of course to be my in car computer. However my car has steering wheel controls and I'd like to at least some how wire the seek buttons so I can change tracks in iTunes or something. This sounds very tricky but I'd like to hear idea's.

It's a 2000 GMC Jimmy SLT with the standard Delco radio but with Bose speakers. It has a Aux button, but not external tape deck using it.

My idea to possibly get this to work is take a spare apple aluminum keyboard and relay the F7 and F9 keys to the switch somehow, but I don't think that would work because those keys are part of the keyboard circuit board....

I may use a spare iBook G3 white I have laying around instead of a mac mini since that's one less thing to buy.

So, what do you all think? ;D

 

[Osgeld]

someone on arduino is working on this for another carputer

arduino handles push buttons and simply feeds it serially over usb to the computer, which can do whatever you like

you could hack up a keyboard, but its a kludge and messy

 

[Christopher]

I could hack a keyboard up and just use the parts I needed from it and it would work ok?

 

[Osgeld]

depends, if you just wanted to use the controller chip and knew the layout of the matrix yea, if your just going to wire tap the matrix then you have a whole stripped out busted keyboard to deal with over 3-5 buttons

but a 3$ chip, a hand full of electronic parts and less than a page of C sounds much easier to me than probing out a 20000000key matrix or shoving a keyboard under my dash (course I already have these items and experience with them, but I dont mind helping if you were to go that route)

 

[Bunsen]

Grab a generic cheapie USB numeric keypad and use software to assign the keys to whatever you want. Label them, pull off the keycaps for the ones you're not using and make up a plate to cover the holes.

 

[Christopher]

@Osgeld That'd be cool but I'd probably do that when I move out so I wouldn't be bothered and stuff wouldn't randomly break.

@bunsen, that's a really good idea, now off, to find a screen and figure out where I'm placing it.

The front dash area is very tight and uses the space available to it fairly well, so I'm thinking for in the even of theft, making the screen slide out. Where? probably between where the passenger airbag is and the stereo and center air vents are placed, no idea what's behind there but we can always look.

 

[Bunsen]

Also the iBook G3 will be just fine if all you need is an iTunes player. With a bit of luck and creativity, you might not even have to buy another display.

What model is it?

 

[Osgeld]

@Osgeld That'd be cool but I'd probably do that when I move out so I wouldn't be bothered and stuff wouldn't randomly break.

no matter what you choose it the quality you put into it that would determine its lifespan, MCU's are put in a lot of "do or die" situations where 100% flawless up time for decades is required

 

[tt]

A roll-up silicone numeric USB keypad may offer more flexibility for the installation.

 

[Bunsen]

True - and with a translucent one, you could even backlight it.

 

[Christopher]

Also the iBook G3 will be just fine if all you need is an iTunes player. With a bit of luck and creativity, you might not even have to buy another display.
What model is it?

First gen 500MHz G3 w/ 8MB ati.

no matter what you choose it the quality you put into it that would determine its lifespan, MCU's are put in a lot of "do or die" situations where 100% flawless up time for decades is required

I meant it as in "people coming into my work area and messing with my layout when I'm not around".

 

[Dennis Nedry]

You could TOTALLY make a serial adapter and hack an old 68k Mac to readout engine stats on an LCD mounted in the dash. That would be SO COOL. If these are normal serial signals, heck you could do it in RealBasic.

This wouldn't be a super-straightforward project, and it isn't my cup O tea, but I think it's worthy of a retro challenge for someone who's into that sort of thing.

 

[bhylak]

That isn't exactly the point of the project...

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This is a good screen: http://www.amazon.com/dp/B000AYG9F6/ref=nosim?tag=spajr-20&linkCode=sb1&camp=212353&creative=380549

Or this one: http://www.google.com/products?q=Xenarc+705TSV&hl=en&aq=f

If you got a new Mac Mini, with the IR remote, you can just strap that onto the steering wheel. If you are going to put all this effort into this project, you want something at least 1 ghz.

How about this for power: CarNetix P1900 Version 2.2

You could use Logitech DiNovo Mini Keyboards to type, without touching the screen...

Depending on the placement you might need IR repeaters and some extra long VGA cords, (DVI to VGA)

If you don't have Audio In on Car you could use an FM broadcaster...

Broadband card...

How about using an AppleTV?

 

[H3NRY]

the iBook G3 will be just fine if all you need is an iTunes player.

If that's all you need, an iPod would do.

It will be easier to power an iBook than a Mini. Car power adapters for laptops are easy. The weird voltage for a Mini, not so easy, but that doesn't stop people. Several Minis in cars are documented online at 123mini and other places.

 

[bhylak]

But the Mac Mini would be the better choice...

btw, if you would have read my post you could of seen the power supply, that works with Mac Minis...

 

[Bunsen]

But the Mac Mini would be the better choice

Why?

@Christopher: Apart from playing iTunes,what do you want this carputer to do?

You could TOTALLY make a serial adapter and hack an old 68k Mac to readout engine stats on an LCD mounted in the dash. That would be SO COOL. If these are normal serial signals, heck you could do it in RealBasic.

They're not.

http://en.wikipedia.org/wiki/OBDII#OBD-II_Signal_Protocols

That said, it's not that difficult. Heck you can read them with a Gameboy

 

[Osgeld]

its just ttl levels which can be read by just about anything, but if you want to hook it directly into a computer port you will need a level shifter to convert the +-12v into 0-5v

 

[Dennis Nedry]

I would imagine that a simple microcontroller + simple analog circuit could be fashioned to make any necessary conversions (even frequency measurements), then ship it out as serial data. I did a project for my college physics class that did something similar. I used a Motorola 9S12DP256 (68HC12 family) <-> Macintosh LC III modem port. I used RealBasic, which was very inefficient, but it was so easy it was like writing a HyperCard stack. All serial communications are already taken care of on both sides, I just called send and receive functions! Communications were able to go in both directions and it even used XON/XOFF handshaking. The LC III had a VRAM upgrade to take it to Thousands of colors at 640x480 for the presentation. This "machine" was interactive with the projector and the actual physical parts! Here's a page about it:

http://www.d.umn.edu/~bold0070/spymac_mirror/projects/goldberg/

 

[Osgeld]

you dont really even have to go that far, a few transistors wired the right way will get at least 9600 baud (or better if you build it right) the shifter I am using now is based on a 7404 hex inverter, and handles upto 115k, but is a bit weird after that, and thats handling a real rs232 port running at 24v pp down to 3-5v logic

or you could go all nutty and use a maxium max232, which is really overkill, and kind of expensive when compared to a 7 cent 74xxXX ic