What's the new project I hear you ask? I'm going to take one of these lovely little microprocessors and make my own trip computer capable of more accurate displays, multiple memories, multiple averages, car battery condition, data logging (hopefully GPS too if I can integrate a bluetooth controller and code a miniature bluetooth stack), and ability to connect to a laptop... as well as anything else I can think of!
What I need to do:
1) Find out how the existing signals - odometer, fuel gauge, economy data (is it sent as the amount of fuel being pumped in?), external temperature are sent to the trip computer. What's on the wires - variable voltages? variably pulsed voltages? i2c data? other data? I'm getting hold of an oscilloscope shortly whilch should clue me in a bit on this, but if anyone actually knows the answers I'd be very grateful!
2) Build a prototype running off 5vdc
3) Program the microcontroller to do the calculations, store the data, communicate with a laptop and of course show stuff on an LCD
4) Modify the LCD screen to match the 406's orangey red colour scheme
5) Build the finished circuitry small enough to fit in the 406's existing trip computer shell with voltage regulation to run off 12v
6) Drink beer!
I'm also pondering what other data I can feed the computer. Recording data from the throttle position sensor would be awesome, but I'm not sure how the thing works and if I can read it without affecting the values the ECU gleans from it. Does anyone have any info on the pin-out and data protocols used in the D8's diagnostics socket? As much as I hate to say it, it'd be a lot easier to do this with a D9 as I could just speak the well-documented CAN protocol. Ah well.
This is going to be a great project and I can't wait to get coding on it
I would very much appreciate any information on the signals going into the standard trip computer though if anyone has access to this information.
, probably cos my electrical knowledge streches to changing a fuse 
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