Megashift working with a few bugs

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.
Gnx412
Posts: 10
Joined: Sat Aug 08, 2015 5:55 am
Location: NJ USA

Megashift working with a few bugs

Post by Gnx412 » Sat Aug 08, 2015 6:33 am

Hello everyone name is Joe I am new to the forums and need some assistance. Have a 90 Deville with a 4t65e controlled with a gpio board built as a 4l80e and it works pretty good :D butttt. When I drive aggressive system goes into manual mode by itself. Wires were wired as force automode for now. Also megashift won't let me set rev checking :| I know a datalog is crucial and will try to get one but maybe my description can lead you guys on to a clue thanks!
It's not your's until you modify the $h!7 out of it!! (87Grand National-90Deville-11Turbo Regal 6sp)

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

Re: Megashift working with a few bugs

Post by Bernard Fife » Sat Aug 08, 2015 6:57 am

gnx412,

Few things can force manual mode (as opposed to force auto mode, which has a number of settings).

Having either of the shift buttons grounded can do it, even though this may be brief and accidental. The best bet if you want to force auto-mode at all times is to tie the upshift and downshift button leads (Amp 15 and Amp 4) to 5 Volts (such as Vref on Amp 28). As a work-around, you might increase the shift button duration: http://www.msgpio.com/manuals/mshift/V5tune.html#gs under Shift Factors

Sometimes if the shift tables are not identical, accidentally using the wrong table (due to grounding or un-grounding of the 4WD switch lead) can lead to no shifts so that it feels like manual mode.

Having the shift table set up so that shifts would exceed the rpm limits will also feel like manual mode had been engaged.

But it's hard to say anything specific without a datalog and a settings (msq) file.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw

Gnx412
Posts: 10
Joined: Sat Aug 08, 2015 5:55 am
Location: NJ USA

Re: Megashift working with a few bugs

Post by Gnx412 » Sat Aug 08, 2015 8:23 am

Thanks so much Lance, I will try to get msq, it was definitely in manual mode because the little box at the bottom changed to manual I'm wondering if there is some error in the firmware because it wont let me save the rev checking option, says burned then if I restart tunerstudios it says you have changes that aren't written and I click write to controller until I'm blue and it just wont burn I'm hoping with an msq of the manual mode happening it will show something
It's not your's until you modify the $h!7 out of it!! (87Grand National-90Deville-11Turbo Regal 6sp)

Gnx412
Posts: 10
Joined: Sat Aug 08, 2015 5:55 am
Location: NJ USA

Re: Megashift working with a few bugs

Post by Gnx412 » Sun Aug 09, 2015 10:30 am

Ok so your info was helpful of course and what I can tell you is that I am sure that it is in manual mode because I see the little box on the bottom go from blue auto to green manual when I get frisky with the throttle. I hooked the wires to 5v and it definitely helped by at least going back to auto mode by itself as before when it went into manual it would stay in manual. I finally got a datalog and hope you can see if I'm missing something or if there is an error somewhere. Just to clarify everything is soldered heat shrunk and does work almost seamless when driving normal around town and on the highway and this is my first mega-product I have built. The transmission is from a 01 Pontiac Montana and I had to fabricate axles and modify some mounts to get everything to work and so far success first shot. :mrgreen: I have two logs one is normal driving but the one that has the manual mode problem says too large very frustrated maybe I can email to you?
Attachments
2015-08-09_12.38.11.msllog1.msl
(631.79 KiB) Downloaded 148 times
It's not your's until you modify the $h!7 out of it!! (87Grand National-90Deville-11Turbo Regal 6sp)

Gnx412
Posts: 10
Joined: Sat Aug 08, 2015 5:55 am
Location: NJ USA

Re: Megashift working with a few bugs

Post by Gnx412 » Sun Aug 09, 2015 10:40 am

second try
Attachments
2015-08-09_14.36.41.msllog3.msl
shorter file with manual mode coming on by itself
(89.96 KiB) Downloaded 150 times
It's not your's until you modify the $h!7 out of it!! (87Grand National-90Deville-11Turbo Regal 6sp)

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

Re: Megashift working with a few bugs

Post by Bernard Fife » Sun Aug 09, 2015 10:42 am

gnx412,

I have asked the forum admin team to increase the file attachment limit from 1 MB to 5 MB per attachment, so you might try re-uploading the log in a little while.

You might also check this post for editing logs to make them shorter: viewtopic.php?f=4&t=1017&p=5500#p5492

One more thing to check when you have problems only under high loads, etc. is that you have very good grounds, as 'iffy' grounds can cause exactly the sort of issues you are seeing.

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: Megashift working with a few bugs

Post by Bernard Fife » Sun Aug 09, 2015 11:05 am

gnx412,

It looks from the second log that the downshift button (DWN in the log) has been grounded from 50.390 seconds until 57.219 seconds. Not surprisingly, that provokes manual mode.

The question is if this was an actual grounding of the down button circuit, or something else. One hint is in the aux channel voltage which is a separate circuit. Curiously, it rises from 0.700 Volts to as much as 2.7 Volts during the same time the downshift button is supposedly pressed, and this suggests to me that either the grounds are suspect, or there is an issue on the board somewhere. The downshift button returning to normal appears to coincide with the pressing of the brakes which again suggests a ground or board issue.

There are also a number of VSS resets at the point at which the button shows as grounded.

That doesn't mean that there isn't issues in the code; there may be and I will have a look on my bench. But the above clues, plus the fact that it happen only under specific circumstances (driving aggressively) suggest a wiring or board issue. So while I look closer on my bench, you might want to have a look at your grounds and your board to make sure these are correctly configured. I would start by making sure that the resistance from my board to the battery's negative terminal is 1.0 Ohm or less.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw

Gnx412
Posts: 10
Joined: Sat Aug 08, 2015 5:55 am
Location: NJ USA

Re: Megashift working with a few bugs

Post by Gnx412 » Sun Aug 09, 2015 3:08 pm

K I checked resistance from pin at board to the body ground that its connected to under dash about.02 The bolt under dash I used is right to the body and .02 ohms. From that bolt various parts of body ground as well .01-.02 ohms. Trans case to batt .002. Again all connections are soldered, ground is an eyeloop soldered. The wiring at trans is wired exactly as its guided in the 4l80e scheme with diodes and resistors close to connector.
It's not your's until you modify the $h!7 out of it!! (87Grand National-90Deville-11Turbo Regal 6sp)

Gnx412
Posts: 10
Joined: Sat Aug 08, 2015 5:55 am
Location: NJ USA

Re: Megashift working with a few bugs

Post by Gnx412 » Sun Aug 09, 2015 3:10 pm

The only other thing I'm wondering is I have a drac box wired into board as another gentleman did is it possible its causing noise
It's not your's until you modify the $h!7 out of it!! (87Grand National-90Deville-11Turbo Regal 6sp)

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

Re: Megashift working with a few bugs

Post by Bernard Fife » Mon Aug 10, 2015 5:45 am

gnx412,

It's unlikely the DRAC is causing problems, unless it is defective (which is possible, of course). You could try by-passing it, I suppose.

If this was mine I would also check the grounds for the alternator and engine to the battery, as ground issues there can cause what seem like ground issues in unattached devices.

It may also be that the 12V supply is very noisy (for any number of reasons), and this is causing the issues you see. In that case, you can put a car stereo power filter in the 12V feed to the GPIO board. Normally this is put in place for reset issues, but it can also solve some problems that are significant enough to cause the sort of issue you see, but not quite big enough to cause resets. There is more information here: http://www.megamanual.com/ms2/tune.htm#resets

Did you try increasing the 'shift button duration' setting? You can set it as high as 1000, and that's what I recommend for you.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw

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