4r70w setup

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

Re: 4r70w setup

Post by Bernard Fife »

is pin 17 on a different ground plane in the board?
ashford,

No. With the low current signal wires having their own ground pin, the path to the only ground plane in the PCB for the signals is separate from the noisy power grounds, making the signals as 'clean' as possible. The intent of the recommended wiring is that users should separate the high current grounds (for driving solenoids, etc.) from the very low current signal grounds as much as possible. The reason is that the high current grounds will introduce a voltage offset in the path from the device to the PCB's ground plane. If the ground pins/wires were combined with the signal pins/wires, even for short distances (even just through through the Ampseal connector), this could play havoc with signal, especially when using PWM, or when using low voltage signals (like EGT thermocouples). Note that the VSS ground is then separated from the other signals to try to reduce the amount of high frequency noise it might introduce in things like temperature signals.

The PC PWM flickering could also be caused by the controller thinking it is on neutral or other gears (due to the voltage setting issue), as there is a specific limit for neutral that isn't affected by load.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
ashford
Posts: 89
Joined: Mon Oct 24, 2011 3:41 pm

Re: 4r70w setup

Post by ashford »

pin 18 has only the mlps and pressure transducer on it so that should be ok then? im just used to the ms with the 10 or so ground plane pins i generally use 3 for signal grounds. 1 for crank only 1 for temps an 1 for o2.

as for the pwm flickering on 4116 the only time pwm is at 100(0 actual) is when the engine is not running i have gear P&N set for 40 if that help with digging for problems in the code.
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: 4r70w setup

Post by Bernard Fife »

pin 18 has only the mlps and pressure transducer on it so that should be ok then?
ashford,

Yes, as long as these are low current devices, they will be fine.

If the engine isn't running, the PWM is set to 0 (indicated as 100) to reduce the current draw. The pressure can't be controlled if the engine isn't turning the pump, after all! I will have a look and see if I have messed up the calculations though. I have likely missed something in setting up the code, and the settings for P/N and 'engine off' are conflicting.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
ashford
Posts: 89
Joined: Mon Oct 24, 2011 3:41 pm

Re: 4r70w setup

Post by ashford »

all above mentioned observations were with the engine running, sorry i did not specify. these problems were not present with 4104
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: 4r70w setup

Post by Bernard Fife »

ashford,

I will post some code you can try, it makes sure that the neutral setting is only used above 300 rpm:
Monitor_4116a_test.abs.s19
However, if you could post your MSQ and a datalog the illustrates the problem (using 4.116 or this code), that would be helpful.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
ashford
Posts: 89
Joined: Mon Oct 24, 2011 3:41 pm

Re: 4r70w setup

Post by ashford »

ill give it a shot after work
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: 4r70w setup

Post by Bernard Fife »

ashford,

I have cleaned up the PC PWM logic (w.r.t. neutral and/or engine stopped), so this version might be better than what I posted above:
Monitor_4116c_test.abs.s19
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
ashford
Posts: 89
Joined: Mon Oct 24, 2011 3:41 pm

Re: 4r70w setup

Post by ashford »

here are the logs from 4116a and msq

for the time being i will run 4104(excuse my dislexia 1404) manually shifting it appears to work, i need to put a load on my engine to seat the rings and rought tune itas the motor is new. ill test the new code probably wendsday or thursday.

also i noticed that the 2 point line pressure always reports 0 but adc works
Attachments
4116a.msq
(43.76 KiB) Downloaded 515 times
running.msl
(159.7 KiB) Downloaded 529 times
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: 4r70w setup

Post by Bernard Fife »

I will have a look. 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: 4r70w setup

Post by Bernard Fife »

ashford,

The datalog indicates that the controller is not finding a gear that matches the voltages specified in the INI. (This is indicated by the -99 manual gear value.) This also causes the PWM% to vary between the table value and 100%. Did you measure and adjust the manual shift lever voltage values for the new code?

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