Simple question..

[Addicted]

My Audi 097 transmission uses 7 solenoids. (Needing 7 outputs)

It also uses a 4 channel switch for gear lever position. (Needing 4 inputs)


Is this possible?

[Bernard Fife]

Addicted,

With the current code, this is only possible if you either:

- give up the line pressure solenoid to use it as a shift solenoid. The spare ports are described here: http://www.msgpio.com/manuals/mshift/spareport.html

OR

- convert to a voltage based shift lever (using a number of resistors with a pull-up voltage). The voltage based lever is described here: http://www.msgpio.com/manuals/mshift/voltlever.html

However, I am in the process of adding the unused pin PE0 pin as a digital shift signal input. That would give us potentially up to 5 digital shift lever inputs, and would leave you with 4 for your application (since you would then use either PAD01/Output5 or PAD03/Output6 as your 7th shift solenoid control while retaining the line pressure control output).

This would require building some custom driver circuits on something like a proto board, of course.

However, if this was mine I would look to see if any of the shift solenoids are redundant, or could be easily control by other signals (for example, they could be controlled directly by the shift lever ground signal). Alternatively, I would check if any of the manual gear lever inputs are not needed (we really only need the lever to differentiate between PNR plus the highest gear, since we can manually select any lower gear using the MShift shift buttons).

Lance.

[Addicted]

Thanks Lance, that confirms what I was thinking.

I was actually thinking of using one of the tiny Arduinos (like an Adafruit Trinket or Arduino Pro mini) to convert my 4 digital signals to descrete analogue voltages by using what would effectively be a lookup table. However an analogue output from an Arduino is in reality a PWM'd 5v so I'm working on the assumption that the ADC on the GPIO board will be OK with that.

I'm not sure yet if any of the solenoids are redundant as info on this transmissions functionality is minimal at best (AND all in German!). I've just completed the build of a multi channel datalogger using a Mega 2560 for the sole perpose of datalogging this transmission. Its going to log speed, load (Kpa), TPS, Engine RPM, condition of 5 digital solenoids and the duty cycle of 2 PWM'd Solenoids. I reckon driving the car for a hour in as many different conditions as possible I will gather all the data I need to map my Megashift.

Whats your opinion on the use of a Arduino to convert the digital to analogue signals Lance?

[Bernard Fife]

analogue output from an Arduino is in reality a PWM'd 5v so I'm working on the assumption that the ADC on the GPIO board will be OK with that

Addicted,

Personally, I wouldn't make that assumption. It may work first time with no problems, or it may require a fair bit of intermediate smoothing (caps and inductors, etc), or it might not work at all (and this might depend on either or both of the frequency and duty cycle, so you might have to do some experimenting with that). The only sure way to find out is to try it.

Lance.

[ashford]

can you post a logic diag of this lever sensor? the new ford 4r70 digital one has 4 logic outs a configuration of using 3 can get you info on what gear you are in, it uses 4 because it also indicates "in between" positions.

[Addicted]

ashford: Logic table as requested, gray code..

15 16 34 35
P 1 1 0 1
R 1 1 1 1
N 0 1 1 1
D 0 0 1 1
3 0 0 1 0
2 1 0 1 0
1 1 0 0 0

Lance: I did some checks, the processor will only see 5v (1023) regardless of the PWM duty cycle..
Fed it through a RC circuit with a 15k resisitor and 0.1uf cap and I now the processors ADC reads the voltage correctly.

[ashford]

im sorry i thought maybee you could remove 1 channel and get a unique signature per gear but no
then i thought maybee you could wire 2 togeter and get a unique sig, but that is a no go also. it seams the logic is perfectly done so it can't get by by loosing one channel.