Monday, 30 September 2013

On-board diagnostics

I had a thought and figured I should write it down somewhere. The Jaguar supports OBD-II, as demonstrated by my Scan Gauge II. It's a big ugly having the gauge sat on the centre console by the gear lever, even if it does tidy away neatly into the arm rest when not in use. I'm sure with a an optoisolator like the one going in to the Mazda dashboard, I could knock up an OBD-II reader out of a the Stellaris Launchpad I'm going to use to decode the radio UI. This means I could put real-time stats on the radio UI. You could use the mode button to knock it between FM, DAB, MP3 and use, I don't know, the Dolby button to put it into real-time gauge mode. The skip up/down toggle would switch between PIDs. I did wonder if anyone had done any reverse engineering on the AJ9500R since I last looked about a year ago. Two of the top three entries on Google were written by me. I take that as a no then.

Saturday, 7 September 2013

Stellaris update

I'm about to try and drive a 4.3" Display-Tech LCD from my Cortex-M4 powered Stellaris Launchpad board.

Yes, this is a different LCD to the one I mentioned previously. I bought two 2.8" cheap and nasty eBay specials and one arrived cracked and the other wouldn't respond to some test code using uTFT. I gave up and decided to buy something a little more professional. Sadly, I seem to have bought the last one RS are ever going to stock. I hope I don't break it.

Anyway, in preparation, I've enabled PLL support and added an option to clock the chip at 66.67MHz. I have a feeling that's going to be helpful later on.

See my github.