free standing trans controller

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.
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jjcoutcher
Posts: 3
Joined: Wed Apr 21, 2010 12:46 pm

free standing trans controller

Post by jjcoutcher »

Do you have to use the MSII to control and program the GPIO? I would like to use it as a free standing 4L60E controller, is anybody working on this?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: free standing trans controller

Post by Bernard Fife »

jjcoutcher,

You can run the GPIO trans controller independently for the 4L60E - though not a lot of people have done this just yet. The board has inputs for engine speed and load, so MS-II isn't essential.

There are a few limitations if you don't use MS-II, though these aren't generally serious - like losing the voltage compensation on the line pressure control, and losing the fuel consumption calculations.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
jjcoutcher
Posts: 3
Joined: Wed Apr 21, 2010 12:46 pm

Re: free standing trans controller

Post by jjcoutcher »

Lance,

I am running a Holley Commander 950 and I know the serial interface has all the data needed. How ever capturing it has not been easy and requests to Holley have not been helpful.

On this car fuel consumption is not my main concern. My 406 is pushing 425 hp and about 560 foot lbs. I have been looking at the 4L60E because it will allow me to drop from a 373 to a 251 rear gear and still run high 11s.

How ever I do not want to lose the voltage compensation on the line pressure control.

I guess I will be spending more time studying the interface between the MS-II and the GPIO to find a good solution.

Thanks for your response.

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

Re: free standing trans controller

Post by Bernard Fife »

jjcoutcher,

Voltage compensation isn't critical, but it is nice to have. It isn't as important as injector voltage compensation, for example, because the engine is always running when the trans is asked to do anything (unlike a cranking engine, when the stater is pulling the voltage quite low).

One way to get voltage compensation in a non-CAN application this is to use the brake sense ADC to measure the voltage, and use that as the measure for line pressure compensation. This would involve no changes to the wiring from the current external schematics, but would need some code changes.

The brake switch would have to be the "ground" type, and voltage compensation would be "frozen" while braking (when it would likely be less important). And the code would have to be modified, of course. Right now the code is quite close to the free "special edition codewarrior" limits, and I don't want to push it over that until necessary to allow users to make changes (and then a number of things will be added at that point).

If there is sufficient demand for the non-CAN voltage sensing, I will add it.

Holley can be difficult to get info from - I had a 900 cfm 4Di that I switched to MegaSquirt years ago (on the 406 in my Corvette) because I couldn't get any info at all from Holley (though their replacement policy was quite good on units that weren't working).

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
jjcoutcher
Posts: 3
Joined: Wed Apr 21, 2010 12:46 pm

Re: free standing trans controller

Post by jjcoutcher »

Lance,

I have made some progress with my Commander 950. I have a program that logs the data stream, to and from the RS232 port on my laptop. Although it gives me a lot more information than I need. It shouldn’t be too bad writing a program to parse out the data I need.

I am a true geek at heart and I don’t like to lose at a challenge. As I come up with some solid information I will post it. I am sure there are others out there with the Commander 950 and the desire to install an electronic trans. Or just pull the data for other projects, like LCD display to replace gauges.

Thanks again for the information.

jjcoutcher
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