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Old 05-07-2008, 07:21 PM   #1 (permalink)
Dan.
MPG Centurion
 
Join Date: Apr 2008
Location: Houston, TX
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LinuxPC + FreeDiags + Freefall OBDII<->RS232

I know it won't do CAN, but this is what I was trying to do way back when

http://www.cleanmpg.com/forums/showthread.php?p=92392
Quote:
I've seen a lot of posts complaining that the SGII is too expensive. In answer to that I've dug through my bookmarks. There was a time in my life where cheap was better than easy. Now I'm not so picky.

So what you need:
  1. A i386 laptop or better with serial and LPT port (0 - $10) - Should take 8 - 40 hours depending on your ebay skills. If someone charges you more than $10 for a 12 year old laptop... punch them in the nose.
  2. A Linux kernel capable of running on #1 ($0.00) - This will take between 4 - 4000 hours depending on how good you are at assembling Linux Kernels.
  3. http://www.planetfall.com/~jeff/obdii/ ($5 - $10) - Should take 16 - 200 hours depending on your digital logic skills. You'll need the proper project boards a hot iron, a laser printer (library) and a good amount of etching acid. Add the proper parts and a soldering iron and you have a (car) OBDII - RS232 (serial) adapter. Make sure not to melt any skin in the process . You don't have to use these plans, just one of the ones supported in the the software in #4
  4. http://freediag.sourceforge.net/index.html ($0.00) - Should take 8 - 400 hours depending on if bugs arise. Checkout the source and compile it targeting #2. This is the software that will talk to your car using #1 through the adapter you made in #3. Please take care to do step #3 properly so as not to fry out your serial port or your cars OBDII port.

So between $5 - $20 cash and between 36 - 4640 hours (0.9 - 116 work weeks) of time.

I made it through step #2 two years ago before giving up and buying the ScanGauge. Cost me $0.00 and about 200 hours of effort.

Don't think this stuff works on CAN cars but feel free to update the freediag software or Jeffs OBDII schematic.
11011011

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Houston Hybrid and Hypermilers Club <106mpg.com>

Best commute = 14.3mi @ 114 MPG (sg2)
Best (non-trivial) tank = 759mi @ 80.7 MPG (fcd)
MPG Centurion-Hybridfest 2007-Prius II-26mi @ 106 MPG (sg2)
Dan <11011011>
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