VN ALDL Cable

[Tazzi]

My mate asked how to connect up to his VN commy to view live data. So had a look, then did a little research and looks like all the sketchs online require an old school serial port. So far what I know is that the VN's comunicate over ALDL 160Baud, and require a 10K ohm resistor to put into diagnostic/ALDL mode.

Alot of the sketchs Iv seen also require transistors and 12v from vehicle.. but in this modern age, looks like we should be able to utilize a simple usb->serial converter along with a 10K resistor to get this working on a usb connection.

So insead of purchasing a $160 VN cable off ebay. Iv made a quick sketch of what I reckon *should* work. The plug below is the VN plug, and the wires leading off are attaching to a little usb->serial board that I have laying around. Anyone let me know if this looks ok or if im missing anything? (Excuse my lame windows windows paint drawing)
*Scrap that last image.. heres one from justcomms

[The1]

Antus is still doing boards, pretty sure this one works for VN and would be prob half the price. Not sure if it's my connection anyway but can't see your pic.

http://pcmhacking.net/forums/viewtopic.php?f=14&t=164

[Tazzi]

Antus is still doing boards, pretty sure this one works for VN and would be prob half the price. Not sure if it's my connection anyway but can't see your pic.

http://pcmhacking.net/forums/viewtopic.php?f=14&t=164

Yeah that is an option. Was hoping to just hack something together using bits and pieces here at home.
So I updated the image to one from just commodores. Now what I dont get is if the data line (pin3) is going to be 12v or 5v.

From what I read off the Tech edge site:

As mentioned, RS232 signals are inverted compared to the bit streams seen by a UART. A GM ECM produces a data signal at either a 12 Volt (SES/CEL style level) or 5 volt level (TTL/CMOS levels) that must be inverted and converted to RS232. One simple scheme is to feed the ALDL data into a single transistor level converter that inverts the data to produce a pseudo RS232 level (varies between 12 Volts and 0). This is connected to the receive data line of a serial device to be processed by a UART.

Another diagram from the tech edge site is found here: http://www.techedge.com.au/vehicle/aldl160/aldl_hw.htm

Q2 converts the ECM's ALDL serial output to a pseudo RS232 voltage.
Q1 converts the RS232 serial voltage to an ECM compatible signal.

SO does a VN/VP commodore have a 5v or 12v data line?

[VL400]

My mate asked how to connect up to his VN commy to view live data.

Its so slow it cant be referred to live data

The data is piggybacked off the CEL pin, so 12V.

[antus]

Thats true. And it also is not bi-directional, hence why you need to bridge the diag mode so that last diagram looks more like an 8192 baud aldl cable. The cpu just bit bangs it out at 160 baud and doesnt use the processors uart. You can see data, but its not terribly useful. The 20 byte data packets are shown here. http://www.techedge.com.au/vehicle/aldl160/aldl_hw.htm

[Tazzi]

My mate asked how to connect up to his VN commy to view live data.

Its so slow it cant be referred to live data

The data is piggybacked off the CEL pin, so 12V.

Haha, I seem to be reading about that alot lol.
Ahhh.. ok.. so need to drop the 12v voltage to 5v for the usb-> serial device. Hmm..soooo:

So based off that diagram, Really I should be able to hook the CTS straight to the usb->serial Rx line. Well I am assuming that R5 (cts) drops the volts to roughly 5v?

Thats true. And it also is not bi-directional, hence why you need to bridge the diag mode so that last diagram looks more like an 8192 baud aldl cable. The cpu just bit bangs it out at 160 baud and doesnt use the processors uart. You can see data, but its not terribly useful. The 20 byte data packets are shown here. http://www.techedge.com.au/vehicle/aldl160/aldl_hw.htm

So you cant write data back? Or.. well you could try but nothing would actually respond/happen.
Yeah that last diagram said that Q1 D1 and R3 arent required if only using 160baud.

[delcowizzid]

only one way comms out of the ecu.as im aware there is no tunerpro adx setup for it either.normally i used to use winaldl (free) and i dont know if it works with usb or only a real serial port.efi live v4 will work too

[Jayme]

at 160 baud I think its like 1 frame per second or worse. this is why its way way easier to tune VN/VP's on an 808 with a serial board and $12p... can then put the tune back into a stock 808 when done. if you need to diagnose something swap in the serial 808 again.

[Tazzi]

hahahaha, 1 frame a second! WOW. Thats absolutely shocking!

I think hes just interested in getting specks up on the lappy just to say he can do it and check out whats what. Im just along for the ride since I showed him what you can do with a VY which got him hyped up to tinker haha. I havent worked on a VN before so its a new experience for me too.

I see most people use winaldl for it and efilive, havent heard of anything for tunerpro though but on fleabay they seem to say it is compatible.

Unless anyone has another idea, ill pop by jay car to pick up the extra resistors and transistor and see what happens

[antus]

Yeah I reckon that might work. You'd need to reference the techedge link to see whats in the datastream, and use info from six_shooter here to set up the adx for 160 baud (select the 160 baud checkbox and configure the port for 4800 baud) by the sounds of it. http://tunerpro.net/forum/viewtopic.php?t=1016