linux and the 944
 

being the linux/computer dork that i am, and having seen linux put on everything from a watch to a x-box ect. has anyone made their 944 run linux???

I wanna know too. yaay for linux :)

Open Based ... Nice!!!

.

I am all for the idea too!

thats cool as hell but i was actually talking about it being like the DME. would you be able to hook it up to where it actually controls air/fuel maps and other stuff?

Umm... well yes and no.
You would need some kind of external controller, like an OOPIC or something, because there is data coming in on too many pins, the controller could convert all the incoming data (with the help of an analog-digital converter), and turn it into a serial stream, which could enter on a serial port of any computer. Then you could write a program to interpret this data, and send signals back out, through the oopic and back to the engine. However I fear that the lag time of all these processes will be too much, and you will have to allow for some guestimating, which will lead to decreased performance.
Plus, if you computer ever slows down just a little, it could stall your car.
that is, don't use it to control your sound system too, lol.

However, the idea itself is pretty cool, but I would feel better programming an OOPIC to run the engine, than trying to interface to a PC.

I suppose you could skip using an external controller, but you would have to use multiple ports, and use an analog-digital converter. Along with many transistors to turn your +5V into a +12V, or a switched ground for the coil, etc...
But, that would allow for some pretty cool anti-theft systems.

would it be possible to burn linux directly to a chip so it runs your DME?

.

in my opinion everything is possible the question then is to know how many time/people/money it would consume for a year to develop something like that.
It would certainely be more accurate and fast in data treatment than a simple 80C51 or Z80 when i see some pocket pc but playing in this game it's only for big boys with big money more than i will ever have.

I'm writing a program right now that takes a stream of data from the Weather Service's satellites, down to our dish, to the demodulator, to the serial port. Serial IO isn't that hard in Java... the hardest part for this project was finding the beginning/end of each packet. If the DME sends a pulsed signal, i can't imagine it being very hard. The hardest part would be making sure you have the exact right formulas or interpration logic. The smallest error in there could potentially cause a ton of damage.

I'd be willing to expirament if anyone has info on pinouts.

I was trying to make a data logger for the 944 DME, the problem I ran into, is you have to solder a wire into the DME to send it data, and it has a bitrate of 93750, which is very difficult to translate into something usable.

so did you come up with anything on the datalogger idea or abandon it for now?

i love linux!

[.

mmhh it seems that the error memory works only with from 1988 ECU :mad:

kraft...vous etes un connaiseur d'electroniques, no? Tres bien!

man, that's a really high bitrate. I'm not sure how you'd deal with that.

Lol no i'm not, i whish, but i'm not...only trying to do with the little i know. :confused:

.

Okie dokie. The serial data logger is temorarily abandoned.
There is no way to make a serial port in a computer read a bitrate of 93750, especially with 9 bit bytes.
So, there are 2 options. 1) some kind of signal converter. This seems to be very difficult. But I have wondered whether I could not set the bit rate to 128kbit, and if it would still work at least 90% of the time.

Next, responding to the DME.
By default, on startup, the DME sends a byte pattern, 0xFF (or something similar to that) to the diagnostic plug. Unless you respond to the DME (which the germans didn't give you a wire to do this on), it then shuts off the diagnostic read-out.
So, you solder a wire into the DME (I think I have hte pin # somewhere, just not with me), and send it back 0XEE (could be wrong there too, have it written down, just not with me), and it says 'ok, now tell me what you want!'.
So, to get any data, you have to poll the DME constantly. That makes it much more complicated, because then you have to talk back to it wiht 9 bit bytes at 93750bps.

My only other thought, is that the 93750 bit rate is determined using 9 bit bytes, and it is actually a common bitrate that has been misrepresented to confuse people.

So, the other choice. Change the DME chips. This has been done with success. You can copy the DME program to another chip, then change parts of it, so it will automatically broadcast the data you want, at a bit rate/format you want.
However, I do not have an EEPROM burner to try this out with.
So, I am still investigating finding a way to read the 93750 bit rate, and soldering a wire into my DME.
I think if I could complete this, I could just copy the program for people, and explain where to solder, making this available to everybody.


Hopefully I come up with something soon.

Nice :)

For a moment i thought this strange bitrate was a joke. Well making a copy of rom is possible nly for electronics hobbyist, not my case. hope someone will be able to make a move with this idea.

The diag plug on mine shows nothing, 0v anywhere on the pins and more than that i have one ecu from the ages , not even able to show errors with the led just because instead of 5 they are 3 connected points where there is 12v and grounding but nothing else :mad:

So i decided to try an alternate way even if it's pain for me but no choice, i will try to find and build a simple analog / digital converter able to send the whole informations through the serial port.
I really can't make wires running everywhere in the car to get in touch with the pc in the rear of the car :D