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 »

Understood.
I can't touch this stuff unless my mind is right for it, and that's just the hardware. Hope you are feeling better, I had a bout of food poisoning a week ago, I can relate.

Pretty busy for me this week, I'd have trouble doing much testing anyway. Get better. I'll wait.

Jim
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: AA80E 8-speed

Post by Bernard Fife »

Jim, here is some test code. It probably won't fix any issues, but it has several diagnostic snippets in it that should help narrow the problems down. If you could try this code (even without running the car) and post the msq and a datalog, plus a concise explanation of any problems you encounter (ideally with reference to specific points in the datalog) we can get it sorted out.
Monitor_5290t2.abs.s19
Test code, use with accompanying INI
(92.02 KiB) Downloaded 464 times
GPIO_MShift_5290.ini
INI for 5.290t2
(314.3 KiB) Downloaded 445 times
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

Thanks Lance, maybe this will tell us what we need to get it working. I think two things are going on, one with the controller and one with the transmission.

-First, because the transmission is not getting the "Shift Trigger" it is expecting it is operating in Limp mode which puts it into 3rd gear when Drive is selected. This is consistent with the documentation from Toyota.

-The controller is seeing a closed switch on it's input for paddle Upshift, which does not change. Could this keep the controller from trying to change gears?

I uploaded the file, updated Tuner Studio, and ran a datalog with the following results:

-"Upshift Pressed" indication in the status bar and this remains unchanged no matter what. Downshift status changes normally when the paddle shift prox is triggered. This is just because of the need to switch the software designations for the upshift input and the shift trigger solenoid output, as we have discussed before in this thread.

- When shifted to "Drive" the laptop display shows gear 1 selected. The dash indicator shows "0". I think the transmission is actually in 3rd gear which is the default limp mode gear this transmission uses if it does not have any input. Based on road speed that would be about right. With the first gear it has (a 4 series gear reduction) it could not achieve the speed it does.
The transmission does not upshift on its own and I wasn't able to get it to upshift. It won't downshift either.

I know we discussed switching these two ports to get the needed number of outputs, and concluded that it was a viable strategy. I followed through with the hardware in accordance with those discussions. If you can switch the upshift input in software with the trigger output I think that will get us a whole lot closer to making this work, then with luck we might not have to do much to make the trigger work properly.

I have attached the datalog from today's test run.

Thanks Lance,
Jim
Attachments
2016-10-13_17.00.54.msl
(1.35 MiB) Downloaded 430 times
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: AA80E 8-speed

Post by Bernard Fife »

Jim, Was this log made with exactly the same settings as the MSQ file you posted previously? If so, let me know. If not, please post the MSQ that you were using at the time.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

Sorry. This should be it.

Jim
Attachments
2016-10-15_12.11.37.msq
(110.48 KiB) Downloaded 636 times
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: AA80E 8-speed

Post by Bernard Fife »

Jim, One more quick question: did you cycle the power after loading your MSQ? Some changes require a power cycle (ie. once after loading the code, then again after loading the MSQ). This power cycle is hard to avoid on a running car which starts/stops all the time, but it's easy to forget the second power cycle when testing.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

Yep, I did do that. In fact I waited a couple hours between loading the new files and making the test run just to make sure the laptop battery was fully charged. I opened TS after the upload and checked the paddle shifter inputs, made notes, them shut down and came back later to do the datalog.

Jim
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: AA80E 8-speed

Post by Bernard Fife »

Perfect, thanks!
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: AA80E 8-speed

Post by Bernard Fife »

Jim, I still don't know exactly what is going on, but the last log helped. The attached code and INI should narrow it down some more. The INI has some renamed options for the port switching, so you might get some errors that tell you to reset some of the input configuration settings when you load your older MSQ.
Monitor_5290t3.abs.s19
(92.12 KiB) Downloaded 443 times
GPIO_MShift_5290.ini
(317.25 KiB) Downloaded 450 times
A log of the results (and an msq) would really help.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Jim Blackwood
Posts: 222
Joined: Tue Dec 07, 2010 9:52 am

Re: AA80E 8-speed

Post by Jim Blackwood »

Thanks Lance,

It's raining buckets today, but I'll get the files loaded and have a look, get ready for the test drive.

I really think what is happening has mostly to do with how the valve body handles shifting commands. Operating purely hydraulically (no electrical inputs) the valve body apparently looks for a trigger to initiate gear selection. If that is not there it defaults to limp mode and applies 3rd gear only in Drive. This is the default hydraulic condition and is what it will do if the transmission has no electrical power, as if the control cable is cut or disconnected.

Now the OEM files we have, say that limp mode will occur if the trigger signal remains low, and also if it remains high. This indicates a pulse is required to the solenoid, which generates a hydraulic pulse in the valve body and initiates the gear change. This explanation is consistent with the name given, of a "Shift Trigger Solenoid".

I am eager to see what happens when we have the software correctly ported to the shift trigger solenoid and hope that these new changes enable that assignment. This was the port that needed switched with the paddle upshift, (PT6/AD4 I believe).

We discussed an existing output configuration setting that might allow a pulse output, I seem to remember something about a "clutch" output? I may have that selected as the output type already and if that works we could be almost home free. I'll take a look.

I've given some thought to pulse requirements. Mechanically the transmission is claimed to be capable of a gear change time of only 50 milliseconds, which is very fast. That would indicate that a 50 ms pulse should be long enough for the trigger but I would think up to 200ms would not be excessive. Timing of the pulse would be the other factor, as there should be sufficient time allowed for the gear selector solenoids to "set" prior to initiating the trigger. I do not know how long this takes, but would think that something up to about 250 ms would be acceptable. Less than 25 is likely to be too little time but as this adds to the delay after commanding a shift it should be kept as low as it will function reliably. It is possible that pulsing the trigger at the same time as activating the shift selection solenoids also works so for testing purposes I'd like to see 0-250 ms and we could use that range for both settings for testing. Once we understand how it works it could be a fixed setting.

I hope this bit of theory helps. I hope to have a new datalog in a day or so. With any luck the new datalog will give us a better idea of what is required and how simple or complex the timing of the trigger pulse has to be. I'll get right on that.

Jim
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