GPIO MShift variant

'Microsquirt' Transmission Control development and support.

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Jim_Blackwood
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GPIO MShift variant

Post by Jim_Blackwood »

Hi y'all. Hope I'm in the right place.
I'd like to sort out how to make some changes in the code for the MegaShift controller and Lance will be tied up for awhile so I thought I'd try here. If I can learn this I have other ideas I'd like to try later on. My son will help me with syntax and such, he's pretty sharp on languages so I'll be asking for help there too.

What I've got is a variant for control of the Aisin AA80E which is an 8 speed auto with 9 control solenoids. As matters stand everything is built and checked out with the exceptions of, 1) establishing communication on the CANbus and 2) switching the AD4 input with the PT6 output in the code and configuring the PT6 output to generate a configurable output pulse for a shift trigger. Right now applying power causes the driver for the shift trigger solenoid to get hot because it's still seen in software as the AD4 input.

I don't know how hard this is to change, but the first step for me will be to identify, download and install the best software tools for me to use. From the sticky, (which I am still reading) it looks like this could get a little complicated/confusing, but all part of the fun.

So if I'm in the wrong place please don't shoot me, a simple lead would suffice. If I am, TIA for your help and I'll try not to be a pest. Headed back to the sticky to finish reading there. Happy to post details of the build if requested, the thread on the MegaShift forum is AA80E. It's a long one though.

Jim
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Re: GPIO MShift variant

Post by jsmcortina »

Have you looked at the Microsquirt transmission control software? That doesn't support your gearbox currently, but it does run on the GPIO too and unlike the MShift code, the source code is available for you to view, edit and extend. (On licensed hardware.)

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
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Jim_Blackwood
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Re: GPIO MShift variant

Post by Jim_Blackwood »

That's very interesting James, I had no idea. But if it works with the GPIO it might make sense to go that way. I will see what I can do to learn about that option, and if you can suggest any links I'll be very happy to follow them up.

Obviously the AA80E goes a bit beyond the typical application such as a 4L60E. I had to add a couple of off-board drivers to the hardware,(mounted to the case end cover) and every possible output has to be used. Then of course 8 gear ratios have to be accommodated. My impression was that in the MegaShift the coding for the extra gears was there and just had to enabled (which Lance did) but I could be mistaken of course. That mainly left a couple of ports to be switched. I gather that the pro version of codewarrior is need to do that, which puts it beyond my reach I would expect.

I'll need to learn about the Microsquirt software and what capabilities it has/mods needed for this useage, but it certainly sounds intriguing. Especially if we can edit the code without expensive software. How difficult would it be to add whatever is needed to get up to 8 gears? If that could be mostly a cut/paste this might be very practical.

Jim
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Re: GPIO MShift variant

Post by jsmcortina »

The "Microsquirt trans" code doesn't currently support eight gears in all places, but it wouldn't be too difficult to do that.

As far as custom development, to my knowledge:
Megashift source code is unreleased, so you can't develop it. Even if it was, it requires Codewarrior Standard which is $$.
The Microsquirt-trans code is available (for customers using approved hardware) and uses a free compiler (same as MS2/Extra.)

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
jsmcortina
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Re: GPIO MShift variant

Post by jsmcortina »

Could you provide a summary of what's needed for that gearbox. I don't really want to look through six years of posts to tease it out.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Jim_Blackwood
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Re: GPIO MShift variant

Post by Jim_Blackwood »

I don't blame you. Me neither.
But I can simplify. Not sure how much time I will have tonight, I will have to dig through some notes, but I think I can give you a pretty clear picture of where I am with the hardware, and what has to happen for the transmission to function as intended.

Basically though, it has 4 clutches, 2 brakes, and TCC. To run those it uses 9 solenoids. 5 are big high flow PWM types, two are smaller PWM, one of which provides a "shift trigger" function, and two are 3 way valves. Although it does use a solenoid to control line pressure that is not the primary means of controlling shift firmness. The big PWM solenoids are used to do that, and apparently the shift trigger solenoid (SR) is used to initiate actual shifting, which suggests that the main solenoids may be "set" just prior to the trigger. I'm not sure what other transmissions use this type of logic, but a comment I just read in GM literature suggests that their new 8 speed also uses a shift trigger, so it's possible it uses similar logic to the Aisin. Whether or not the smaller Aisin trannys use this logic I couldn't say.

I have 14 outputs:
PT1-SL4-Clutch4-PWM4-Output3
PT2-PC-Line Pressure-PWM3
PT3-SLU-Brake2/TCC-PWM2
PT4-Speedo out-PWM1-Output8
PT6-SR-Shift Trigger-EGT2
PT7-SL2-Clutch2-VB1-Output7
PM2-SL3-Clutch3-VB4-Output2
PM3-LED2-GPO2
PM4-LED1-GPO1
PM5-LED3-GPO3
PW1-SL-TCC/REV (on/off)-EGT4
PE4-SL1-Clutch1-VB3-Output1
PA0-SL5-Brake1-VB2-Output4
PB4-LED4-GPO4

As you can see, we had to take every output option we could beg borrow or steal, but with the two drivers mounted to the case it was just enough.

I'd guess you might like to see my configuration file, and the rest of the port assignments. I tried to stay as close to the standard build as I could but still ended up with 7 jumpers on the jumper header:
PE0-VR4-Auto mode/kickdown
AD4-VR2-Paddle Upshift
AD1-GPI2-Shifter Reverse switch
AD0-GPI1-Shifter Drive switch
PT6-EGT2-Shift Trigger (SR)
PE1-EGT4-TCC/Reverse (SL)
PT7-VB1-Spare Output1 (SL2) Clutch2

So the input ports would be:
PT0-VSS-VR1
AD7-Brake sense-GPO1
AD6-Paddle downshift-GPO5
AD5-Non CAN input-EGT1
AD4-Paddle upshift-VR2
AD3-Input3 Park/Neutral-EGT3
AD2-Temp sensor-GPI3
AD1-Input2 Reverse-GPI2
AD0-Input1 Drive-GPI1
PT5-ISS-VR3

The line pressure sensor in the transmission is a switch rather than an actual pressure sensor and is only used as a fault sensor for one gear. I couldn't see a lot of use for it so I stole that port.

At this point I still have PT6 and AD4 with their default assignments in the software, which makes the driver for PT6 get very hot (and paddle upshift does not work) and I've already burned up one diode there during testing. I still need to configure CAN and we do not have a configurable pulse output on PT6 but otherwise I think it is ready to begin testing.

I'd be very interested in hearing what you think.

Jim
Jim_Blackwood
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Re: GPIO MShift variant

Post by Jim_Blackwood »

Hello?
GT1-20b
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Re: GPIO MShift variant

Post by GT1-20b »

Hello Jim,

My name is Carlos Lopez.
I'm the owner or CLR Motorsports in Florida.
Besides being a ex-professional IMSA racing driver winner of Daytona 24hr. and SCCA GT-1 Champion.
I supplied racing Rotary engines to Mazda
North America for the American Le Mans Series, from
04-07. Reason I'm reaching out to you is as follows:

Been researching any and all leads and post with full intentions to run an Aisin AA80e controller by a full Stand Alone controller or the Cadillac varient. Doest matter.
My idea/design/project is to cut off the bell housing, delete the Torque Converter, and replace with a standard OEM Bell housing and dual disc racing clutch and Ultra light weight flywheel thus doing away with the mass of the Converter and this increase the rate of acceleration.
I did this same thing with a Turbo 400 when I was 17 for my 1970 Trans Am. Absolutely LOVED IT. It was THE BEST of both world. This will be the same, but 8 speeds instead of 3.
When I sold the car in my 30's I pulled the gearbox and kept it. Installed am Monsi M-22 and sold.
I still have the gearbox. Can send pics to prove it.

Could easily use a Zf 8hp, with a controller already available and all bugs already worked out, but the Aisin has FAR better gear ratios, and What I learn way back with my TH-400 to increase Torque Capacity and shift speed, I can apply to the AA80 and build a system well capable of handling 1200 Mn or 900 Lbs/Ft. of Torque.
With this project, well it's a system. It's adaptable to any vehicle or car brand by simply changing the bell housing. My personal desire is to build a full race gearbox, that can easily be driven on the street.

I know nothing about electronics. But I also know that a simple controller to work only on shift commands as in full manual mode. On demand Neural, free rev launch, disengage between for smooth shifting, up or down, all aspects of a manual plus all benefits of a Clutchless automatic.

The gearbox will not need a solenoid for Lock Up, as there will be no converter. I believe the un-used solenoid could be the missing link to make the
MegaShift box work.

I'd like to make a Full System that could be bolted up to any engine, with its own proprietary controller.

You seam to understand the electronics well.
A simple almost analog controller would work.
No shift strategy would be necessary although would be nice.

Think about this and please respond regardless if interested or not. I can do all the mechanical part and parts . I need help with control electronics. We can work together to make this set up a complete
St sawand Alone "System" to all that's interest in a race worthy "Semi-Auto" 8 Speed.

Kind regards, and please respond at your earliest convenience.

Thank you,

- Carlos Lopez.
Last edited by GT1-20b on Wed Apr 12, 2023 6:42 pm, edited 6 times in total.
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