The iphone + obd2 = sweet fe instrumentation possibilities?
 

They're already doing it for non-fe things: iPhone OBD-II app - Hack a Day

I'm interested, would be nice to have the processing power and display.

I'm just planning to put an old laptop in the car. The display is awfully nice on my ipod touch though, true that.

The thing about that app talked about in your link is that the interface doesn't exist yet, and when it does it isn't likely to be cheap.

I think the hardware is a combination of a obd-serial reader and a bluetooth modem, but they were a little sheepish on the hardware details :)

Note, the mpguino now outputs useful data on the serial port (as of .74). It should be easy to wire it up to a laptop/cellphone.

Or you can hook up a bluetooth modem (like $65) from a place like sparkfun, or maybe the $40 smd module will work? I haven't really looked into, or used,
bluetooth much so I don't yet know the difference. Wire is cheap :)

The iphone/ipod app is going to use wifi for its interface, not bluetooth, according to the product page. (such as it is)

Ah. I was looking into why they might make a choice like that:
"Neither Bluetooth nor USB-based serial interfaces are available to
developers from the iPhone SDK."


Don't know why usb/bluetooth should be off limits, but there it is. Maybe you have to pay money or something to develop for those ports?

Oh, man, don't even get me started on Apple's insane lock-down of these devices. There is a long, long list of things that third-party developers are not allowed access to. That's what the whole "jailbreak" thing is all about, and why a lot of the App Store apps suck in various ways that they shouldn't have to.

Hmm... well here is another idea on how to talk to an iphone wirelessly from a simple microprocessor device:

1. figure out how to record voice , only from an application that just examines a small portion at a time.
2. hack a wireless headset so you can send different tones from your microprocessor to relay the information you want to send.
3. interpret the "voice" data to make sense out of it in your application
4. use pretty graphs/drawing api to wow people with your new fangled speedometer :)

Would I be able to play music at the same time? That would be really really cool.

Wtf is a wifi obd-ii dongle?

If you need more processing/display how about using a windows mobile device? I have an acer n50 pda, it has bluetooth, serial, usb, nice big touchscreen...

Well, this was a iphone specific thing. It's weird though, if you HAVE to use 802.11 to talk to an external device, then you might well consider giving the external device enough power to serve up a "web page" and be able to use it with anything that has a browser and 802.11 support.