Connecting a laptop
Connecting a laptop
Author
Discussion

simonsparrow

Original Poster:

1,599 posts

291 months

Saturday 30th April 2005
quotequote all
Hi,

Just being trying to do this for the first time, but no joy so far. Are there any special settings for the COM port such as baud rate, flow control etc?

I've got a compaq NX9005, so I've disabled the on-board modem. I've also tried changing the port to COM2 on the PC and then in the TVR software using F10.

The cable I'm using is (was) just a serial extentsion cable, but I've also changed it so that pin 1 on the ECU goes to pin 5 on the PC (as per the MBE lead diagram).

I think the car has a faulty O2 sensor, but it would be good to know for sure!

budaholic

1,516 posts

264 months

Saturday 30th April 2005
quotequote all
No sarcasm intended!!, but have you switched on the ignition?

Bud

nervous

24,050 posts

259 months

Saturday 30th April 2005
quotequote all
when and if you figure it mate please let me know, ive ben trying for months without any success

simonsparrow

Original Poster:

1,599 posts

291 months

Saturday 30th April 2005
quotequote all
Good question, but yes I have.

I've got rid of the fault (which I suspected was the O2 sensors) by replacing the one on bank 1, and when that didn't work, just connecting up the one I'd removed from bank 1 in place of the one on bank 2. I just left it lying on the inner wing and fired the car up to verify the the MiL light would go out. So the sensor for bank 2 was faulty, same one as last year.....

Having a working laptop connection would've saved a few hours though

My cable also connects through pins 4 amonst others, should the laptop to ECU cable just be the three pins?

tvr-fan

237 posts

258 months

Saturday 30th April 2005
quotequote all
nervous said:
when and if you figure it mate please let me know, ive ben trying for months without any success


Didnt i offer to come and plug mine in for you bud ?

simonsparrow

Original Poster:

1,599 posts

291 months

Saturday 30th April 2005
quotequote all
nervous said:
when and if you figure it mate please let me know, ive ben trying for months without any success


We have the same laptops I think, so if I get anywhere I'll let you know.

We also tried with another laptop that a friend had, but no joy, so maybe its the cable. Thats why I was wondering if only 3 wires need to be connected......

tvr-fan

237 posts

258 months

Saturday 30th April 2005
quotequote all
My cable is connected exactly as the drawing from MBE and it works fine

simonsparrow

Original Poster:

1,599 posts

291 months

Saturday 30th April 2005
quotequote all
tvr-fan said:
My cable is connected exactly as the drawing from MBE and it works fine


I've got pins 3-3, 2-2 and 1-5 (ecu/pc) connected up, but the others are all straight through. Do you know if your cable has these 'extra' wires (pins 4,6,7,8,9) connected up too? I wonder if thats whats confusing it.....

tvr-fan

237 posts

258 months

Saturday 30th April 2005
quotequote all
I dont have any of the other pins connected, i made the cable myself, easy job.

simonsparrow

Original Poster:

1,599 posts

291 months

Saturday 30th April 2005
quotequote all
tvr-fan said:
I dont have any of the other pins connected, i made the cable myself, easy job.


Cool, I'll try and snip the 'extra' wires and see if that helps.

budaholic

1,516 posts

264 months

Saturday 30th April 2005
quotequote all
Me too, I made my cable up exactly as the MBE diag, works a treat.

However..... does anyone know why my laptop reboots every time I exit the software?

Very annoying

Bud

nervous

24,050 posts

259 months

Saturday 30th April 2005
quotequote all
answer a: character

answer b: "they all do that sir"

mikesr

672 posts

260 months

Saturday 30th April 2005
quotequote all
Its been a while since I've debugged screwy serial comms but in pretty much every case it was the handshaking that was mismatched betwixt the cable and the port configurations of teh kit at each end of the cable.
Anyway here goes:-
The cable in the diagram on the SBD site has resistors to pull pins 4,6 and 7 to pin 5 (signal ground). These pins are DTR, DSR and RTS which are used for hardware handshaking (switching them high/low with positive volts or zero volts) so Easimap can't be using hardware handshaking. It may be using software handshaking (XOn/XOff) or none at all. Presumably the diagnostic software is the same since its reported this cable works with the diagnostics.
The comm port settings on the laptop can be twiddled with to try no handshaking or xon/xoff. Also make sure the baud rates are the same in the comm port and software setup. data bits 8, stop bits 1 and parity none is the other usual settings and generally the windows default.

It has been reported that a standard cable from your favourite PC store has fried the interface on the laptop. That could be the problem so if you have any other kit with a comm port (is there any other kit that still has a comm port!) see if the laptop works with that.

mikesr

672 posts

260 months

Saturday 30th April 2005
quotequote all
The reboot is built into the software (why is anyones guess)
The simplest way to stop the reboot is to open a file for edit with a program that prompts for saving any changes when it is closed (like notepad).

Open the file and make a couple of changes

When you exit the Diagnostics and the shutdown starts it will try to close notepad.
Notepad pops up a dialog promptig you to save changes yes/no/cancel
Clicking on the cancel button will actually stop whatever process caused the dialog to appear (ie the shutdown process)
So click cancel and the shutdown is halted.
Bear in mind that the shutdown closes any and all open programs so other stuff you had runnign may be stopped before it gets around to closing notepad.

supaspark

2,105 posts

267 months

Saturday 30th April 2005
quotequote all
Jeees...I'm glad all I need is a strobe gun!

malman

2,258 posts

288 months

Saturday 30th April 2005
quotequote all
budaholic said:
Me too, I made my cable up exactly as the MBE diag, works a treat.

However..... does anyone know why my laptop reboots every time I exit the software?

Very annoying

Bud


On Windows2000 it just logs you off - still annoying but less so than a reboot