Source code 101

[bruce]

Here's an excellent thread to read thur, and download the referred links, from.

http://www.thirdgen.org/techbb2/showthread.php?s=&threadid=245659

It makes life soooo much easier.

This is letting the cat out of the bag. No longer are you chained to using the stock code. With source code you can run whatever you have the imagination to program.

Lotus Boost control?. That's on the net. ie learning boost just like the BLs in closed loop fueling. Graft it in and away ya go.

 

[BoostKillsStres]

Bruce, That looks like a bunuch of good interesting stuff, thanks for pulling that over. By the way, I googled for "lotus boost" but didn't come across anything, you have a link for that or a quick explanation? Does it slowly increment boost scalers unless it detects knock or something then decrement a step if knock is seen so the next pull has a new adjustment?

 

[bruce]

Originally posted by BoostKillsStres
Bruce, That looks like a bunuch of good interesting stuff, thanks for pulling that over. By the way, I googled for "lotus boost" but didn't come across anything, you have a link for that or a quick explanation? Does it slowly increment boost scalers unless it detects knock or something then decrement a step if knock is seen so the next pull has a new adjustment?

Just off hand I can't find the URL at the moment, but someone's posted the source code for the Lotus V8 Turbo car. It uses the same ecm as the ZR-1's did. So it's all in gmese.

It has a learn function for the wastegate, trims the boost as a function of knock.

If your serious about wanting to see it, write me an email, as a reminder, and I'll dig around more later. Memory's completely gone.

 

[BJM]

Just as a point of interest I am working on making my boost controller learn as well. It would trim the WG DC based on measured over or under boost. I find it annoying that my boost will rise 1-1.5 psi just because the weather was cold one morning.

 

[skwayb]

Mark,

Darren Freed posted this to the GMECM list on the Lotus Code.

Lotus Carlton code (AXSH) actually has the best boost control code I've seen so far. It has WG BLMs and very precisely controls boost. I've grafted it into $8F and into $2E('6401) (both of which I've tried on my car).

More information:

The Lotus code is for the early 90s Carlton which has a inline 3.6L 6 cylinder, twin turbo with air/water intercooler - makes around 375 hp and 420 ft/lb torque. Uses the same ecu as the corvette ZR1 - 1228331.

Here is the link to the disassembled code. It is at the bottom of the list.

http://home.cc.umanitoba.ca/~umfreedd/index_files2/ecm.html

Hope that helps you.

 

[BoostKillsStres]

Thanks Paul, I can certainly get lost in that stuff for a while.

 

[ijames]

Just in case someone needs the basics of programming on our ecms, the microcontroller used in our ecms is a gm-specific version of the 6800 series made my Motorola. Motorola moved their chipmaking business to Freescale (www.freescale.com). The 68hc11 is a slightly extended version of our chip, with a few extra instructions that won't work on our ecms but so far as I know all of our instructions are implemented in the 68hc11. The full manual is at http://www.freescale.com/files/microcontrollers/doc/ref_manual/M68HC11RM.pdf and is 5-6 MB in size. Chapter 6 is the most important for coding. An abbreviated version is at http://www.freescale.com/files/microcontrollers/doc/ref_manual/M68HC11ERG.pdf only 1.2 MB so much faster to download.

 

[BJM]

Unimplemented opcode

I ran into an opcode that doesn't work.

XGDX - Exchange D with X opcode 8F just doesn't work. I really needed it for the space I had. All it does is clear the IX register apparently.

 

[ijames]

Yeah, the 68hc11 has instructions the old 6800's didn't, but it's so hard to find a 6800 programming manual these days that it's easier to just use the 68hc11 manual . I did come across this link http://www.swtpc.com/mholley/Notebook/Notebook_Index.htm which is pretty readable and covers the 6800. The 6801 is a 6800 with ram and rom so physically it's pretty close to the one in the ecm, but codewise it's the same as the 6800. Gack, I'm old, since the 6800 is essentially code identical with the Rockwell 6502 used in the old Apple I and II (Jobs wasn't sure which was going to be available first so the Apple I motherboard actually had a jumper so they could use either one) and I did my first firmware programming (burning code into an eprom) on a 6502 development single board microcomputer system. Now, where's my cane and bifocals?