AA80E 8-speed

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

I have news. It is now possible to download nxp's evaluation version of the IDE and have a 64K compiler limit. In 30 days it will revert to the free version. I do not know yet if it then retains the 64K limit but will report back here if it does.

This is very important news for us, since the file size of the v5.201 firmware is currently in the 50K range. It can be compiled with the codewarrior IDE without incurring the expense of the $1000 commercial download.

I'm currently working my way through Kernigan's C programming text and am about halfway through the first chapter and have read through the appendix B standard library. I decided to use the codewarrior ide for working through the examples to familiarize myself with it at the same time but this is not as easy as it might sound as it is a very complex environment. Still, I think this is the best way to proceed.

I will continue on two fronts, pursuing the code variant, and also nerfing the controller to use standard code. Still a long way from a solution, but faster than switching to another automatic transmission, which I have considered. The GM 8 speed is available at the GM parts counter as a part number but their computer system shows 0 stock available for shipping and I have not yet contacted anyone relevant in their performance branch. Retail price is around $8K but news releases hint at a much lower cost of about half that, with controller and wiring. Some may be available by now as salvage. If the performance branch has not yet developed a standalone controller, they may be considering it, and if available and able to communicate with the engine controller, this would probably be the most practical solution for most owners considering a modern multispeed automatic, depending on their engine choice. For me with a Buick and BOP bellhousing, a simple 1/8" thick $100 adapter plate would do the trick.

Meanwhile, Aisin has found additional buyers for their 8 speed, the AA80E, and expanded the market. Although most of these are still being used in Japanese automobiles, the strength and durability makes them a good choice for many of today's performance oriented cars worldwide and in the US as well. That may not mean more of them get used for hot rodding, but as the generation raised on computer free cars ages, we can expect to see more young guys with the skills to use them, causing EFI, engine management and transmission management to become the norm rather than an offshoot. Ultimately as the push develops towards ever more user friendly electronic systems (a trend that is rapidly gathering momentum) we can expect to see transmission controllers follow the path of efi systems towards plug-n-play functionality. In respect to that, what we are doing here now represents the infancy of this branch of automotive development. I do not know the intentions of the MegaShift community or DIYefi regarding this, they are likely to be stretched pretty thin just covering the engine controller market with the competition now coming from the more established aftermarket companies and we may not be able to expect much support here. Nevertheless, you only have to drive a modern auto equipped rental car to know OEM's have entered a new era in transmission control, and no younger buyer will ever be satisfied with the old again. Presently MegaShift seems to be pretty static. Not a lot has happened on this board in the last couple of years as far as I can see. This arena is one in which you either advance or fall behind, no other option is possible. And it is beginning to look like Megashift could be in danger of the latter. I'd hate to see that, but it's not for me to steer the course, I can only steer my own.

More later.

Jim
steveh66
Posts: 11
Joined: Tue Oct 23, 2012 7:26 am

Re: AA80E 8-speed

Post by steveh66 »

Keep us posted. This info helps all.

and Good luck with progress Jim.

Steve
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

I'm not sure if you can just run a "C" program in codewarrior to test the code. We couldn't figure out how to do it, though there may be a tutorial somewhere that shows it. I'm a reluctant student, but will try to look for it. In the meantime I've downloaded DevCpp so I can do the examples in Kernigan's text. Still trying to get past "Hello World". It's gonna be awhile.

Jim
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

I think I'm beginning to see why Matthew made disparaging remarks about the codewarrior editor. It seems to be so far behind DevC as a code writing tool as to be in the stone age. Perhaps not, maybe I'll learn it has other virtues, but right now those are not apparent. For instance DevC has auto functions for format and syntax that vastly simplify the job, and good color coding of text. CW, not so much.

The thing about writing code though is that there are a million ways to do it wrong and only one way to get it right. A good IDE can cut that million down to just a handful. A bad one? Adios, YOYO.

So FINALLY, I can start working through the text examples. With DevC it was pretty easy to figure out. Once I had a blank project opened, the example was easy to enter, compiled and ran flawlessly. THAT is what I'm looking for, not some string of compound incomprehensible errors.

Jim
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

Lance,
Could we maybe back up to about page 22 or thereabouts and reset?

At that point we were working with v5.290t3 and we got off on this tangent about DDRT and coding. I'll be perfectly honest, I do not want to learn to write code. I really don't. I admire you greatly for your ability to do that. My mind just doesn't work that way and I do envy you those abilities. I'll never get there.

So what do you say? Is it possible to go back and see if there is a way to finish this project?

Jim
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

Been awhile.
Like all before me I punted. Yanked out the 8 speed and installed a T5 instead. At least I get to drive the car.

I still have everything. I can either set up a test bench and eventually try to get it right, or sell it all off piecemeal. No immediate decisions.

Of interest, Cadillac used the Aisin AA80E in one of their models. Used a different code for the tranny though, not AA80E.

I may be back here again, I may not. Right now I'm pretty disgusted with being abandoned right at the finish line.

Jim
superdve
Posts: 8
Joined: Tue Mar 18, 2014 2:16 pm

Re: AA80E 8-speed

Post by superdve »

It's hard to break new ground or even travel ground not well travelled.
My A340E is oh so close to working right in my Scamp. It would be nice to
get the CAN messaging working right so I could get IDLE UP to work with my tight
converter. Alas, probably go 4L80E and some other controls if I can't get help.

That's all I need..but...
Rukavina
Posts: 47
Joined: Fri Aug 15, 2014 7:58 pm

Re: AA80E 8-speed

Post by Rukavina »

Been like the desert here
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