4L80E code

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.
Post Reply
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: 4L80E code

Post by Bernard Fife »

Dave,

You should have got 1.100 for both the code signature and in the INI, that is the new designation for the first release code (though their were no actual code changes compared to 1.006 - just the INI change to include the ISS input that you noted).

So the 1.100 INI will work with 1.006 code, but the code attached above has changed the signature to 1.100 to match the INI

I use both MT and TS, but in this case I checked with MT and got no warnings, etc..

Lance.
"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: 4L80E code

Post by Bernard Fife »

For those that might be interested, here is my TunerStudio project folder (for the latest code/INI):
MShift_TunerStudio_project.zip
(24.31 KiB) Downloaded 586 times
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
6bt4l80e
Posts: 10
Joined: Sat Aug 08, 2009 5:40 pm

Re: 4L80E code

Post by 6bt4l80e »

dch wrote:Hi Tim
Here is a pic for you, All transfer cases have a low gear ratio and when in 4WD low the speedo output has changed. So the GPIO has logic for that. your TPS should be fine the only thing I'm not sure on is engine rpm input Brad is correct in that ISS shouldn't be used as engine input. I don't know options right now but we will get it figured out. Dave

Image
Oh I see the output speed sensor is in the transfercase so that is why it needs to know for 4wd. In my set up the output is still in the transmission as the transfercase is the older NP 205 which dose not have a speed sensor. So I would just build it as a 2wd i would imagine.
6bt4l80e
Posts: 10
Joined: Sat Aug 08, 2009 5:40 pm

Re: 4L80E code

Post by 6bt4l80e »

DCH,

Thanks for posting the image of your board.
gui67
Posts: 134
Joined: Tue Oct 05, 2010 11:58 am
Location: Strasbourg, France

Re: 4L80E code

Post by gui67 »

Hello,
I just installed MS3 on myengine.
I plan to use a 4L80e transmission for next year and therefor use megashift.

I have some questions about the controller: Is it possible to use a switch in order to either have an automatic control or to have a manual control with no kickdown for example.
how do the upshift and downshift switches function: arethey active all the time or only in certain conditions?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: 4L80E code

Post by Bernard Fife »

gui67,

The code starts in one of the two user-selectable auto-modes (sequential shift or skip-shift). Manual mode can be selected at any time by pressing either shift button. Once in manual mode, auto-mode can be re-engaged by:

* pressing and holding both shift buttons simultaneously,
* exceeding either of the user-settable over rev or under rev limits (CAN-enabled only),
* dropping in speed to under 8 mph (from over 20 mph) without selecting first gear in 2WD mode.

In Auto mode:

* Gear is selected according to a 12x12 (mph X kPa) shift table which selects the target gear based on the current vehicle speed and load (the lookup table is user configurable). Load is based on an average (the period of the averaging is user-settable) of the instantaneous load (load is not sampled while braking).

In Manual mode:

* Full manual control with an upshift button and downshift button (that ground their respective connection to the GPIO board), unless rpm exceeds user-specified redline or drops below 10 mph in 2WD mode (CAN enabled only),
* Revert to auto-mode at any time by pressing both shift buttons simultaneously.

This is here: http://www.msgpio.com/manuals/mshift/index.html

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
gui67
Posts: 134
Joined: Tue Oct 05, 2010 11:58 am
Location: Strasbourg, France

Re: 4L80E code

Post by gui67 »

Thank you Lance.
I did understand as the automatic mode is working, but not the way to switch to manual.
now it is really clear.
Is there any important function in megashift that is missing compared to other TCU?
Is the kit from DIY autotune complete to mount the board for this application?
Thanks
Guillaume
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: 4L80E code

Post by Bernard Fife »

Guillaume,

I am not aware of anything that is missing (though I haven't looked at any other controllers at all). This code is based entirely on my desire for a full-featured, flexible trans controller that could be used for road-racing with a variety of automatic transmissions (without requiring code changes - changes to the user parameters in TunerStudio should be sufficient).

My other goal was to have the controller usage as fully documented as I can (this does seem to be a significant weakness of many other systems, unfortunately).

If there are useful functions that are not currently in the code that enough people want added (either to support other transmissions or other uses), I will add them if it is possible.

I believe the DIY base kit plus trans conrtoller components is sufficient, but DIYat is the best place to ask.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
gui67
Posts: 134
Joined: Tue Oct 05, 2010 11:58 am
Location: Strasbourg, France

Re: 4L80E code

Post by gui67 »

thank you Lance for your answers,
it really seems the right controller for my application. After having read the manual more deeply, I don't see anything missing compared to what I will do with.
gui67
Posts: 134
Joined: Tue Oct 05, 2010 11:58 am
Location: Strasbourg, France

Re: 4L80E code

Post by gui67 »

Hello Lance,
can you confirm me that the 2 articles from DIY autotune:
http://www.diyautotune.com/catalog/gpio ... p-403.html
and
http://www.diyautotune.com/catalog/gpio ... p-404.html
are the 2 only things needed to control the 4L80e?

Are there any modiications to do on the main megasquirt board? What should I do to connect both megasquirt and megashift?
Jumper JS6 to SPR1 and JS8 to SPR2. is anything else required?
Post Reply