pcmhacking.net

I went to the wreckers today to get a few more ECM's ( 808's )

I got a ECM from a auto VP commodore and it happened to be a VR manual ECM Sweet.. ( I dunno if this is good or bad but i know its rare )
I popped my Kalmaker memcal in it and managed to get 8192 data on the Kalmaker Gauge screen so it works..

Now does anyone have a circuit that they wish to share for connecting the 1 wire VR data pin to the PC

My old kalmaker setup ( that I wish to replace ) uses the parallel port ( not serial ) to connect to the ecm so I Cant us this with TP and OSE12P
until I made up the interface from ecm to rs232

I tried the diode and resistor mod but no go.. ( this was connecting to a TTL USB to RS232 adapter.. )

I assume the crude diode resistor mod is just to try and stop the transmitted data from the ECM going into the transmit ( output of the pc )
I looked at the data on a CRO and it looked ok ( correct polarity and 5V and same voltage I see when using kalmaker ) but no link with TP

I am using a 12P BIN

If I run kalmaker and look at the gauge screen I can actually get data from the 12P bin ( as the fields are not identical in the aldl streem the data is not correct but I can get some to change like TPS via my bench ECM connected to POT's etc..

So the aboce proves I got the ECM working and the BINary ( 12P ) all good

The charger runs with 202 methenols BIN its currently carby with camira module for timing only .. so 1/2 EFI

Am I wasting my time with the 1 wire VR ECM ?? should I get a VN " chipless " ECM instead and ad the MAX 232.. ???

I just want a reliable ECM that works ( all the time ) with TP

Trying to get rid of Kalmaker.. and old DOS LPT1 and dongle..

How important is setting the latency to 1 in control panel device manager ? for the USB serial port ?
I havnt changed it from the default 14 or whatever it was and after some googling it looks like its a common issue wuth 8192 aldl stuff

that circuit works, but is very susseptible to electrical noise, ive noticed it buggers up and drops packets a lot if the blower fan is turned on etc. all the noise went away once I got a board based on a max232.
its so simple tho its worth using to get you up and running and see how it goes.


ive never changed any settings in device manager for the serial port and it works fine.

Thanks for that..

I just got it working.. I had to set the latency timer to 1 ( this is only required if you are using a usb to rs232 adapter )

There is a very complex reason why ( to do with interupts etc ) USB is just not the same.... ( if your data has no hand shaking ) like it does for the ECM.

very intersted article of why ( if anyone is interested )

http://ilektron-x.blogspot.com/2010/02/ ... opped.html

This is what tipped me off..

http://www.dynamicefi.com/USB2SerialSetup.php

I wasn't sure if the above link related to our ECM's but thought it was worth a try..

But it works now..

Im just using the bodgy 1 diode and one resistor mod so I may wire up a more suitable circuit if needed.

confused... I use an FTDI usb > serial cable and it works fine, never had a problem uploading calibrations and never touched the latency setting.

I changed it back to a latency of 16 and it didn't work. Then put t back to 1 and it worked.. ( I also tried 4 and 8 and they worked also. but I will leave it at 1 )

thats odd. I just checked my setting and its at 16 and works fine, and I dont get those problems talked about where the data somes in bursts or not at all. its a bit of a mystery as to why yours doesnt work unless you change the setting. are you using tuneprro to log? and flashtool to flash? thinking maybe it couldbe the programs you are using?