on my car it's definately pin 12 is +12v perm live feed. Simple check with a multi meter will confirm. There is also an ignition switched +12v at pin 15.

 

Thanks for the info. My pinout seems to be fine. Any ideas on why I can't connect?

 

Some laptops, especially on battery power, will lower the voltage to the USB port. I had this problem trying to run a TI MSP430 programmer with a USB-to-Serial cable...was able to fix with a simple setting but unfortunately can't remember how (it was a while ago). Some searching on Google should tell you. My laptop has 4 USB ports; when on running on batteries one port stays at full voltage while the other 3 drop down.

You may also want to check under Control Panel -> System -> Device Manager -> Ports and ensure that USB-to-Serial is showing up, working correctly, and assigned to the correct COM port.

 

The com port works fine and is assigned to com1 (via device manager). I can see from the leds on the interface board that activity to the board takes place, but no luck connecting to the dme.

I suspect the low power and voltage level (5V) from the usb port on battery power is the problem.

 

Many of the USB/serial converters will simply not work with odd baudrates. You should find a converter that uses the FTDI chip--and possibly install the latest drivers. The first USB converter I tried was a Belkin and it would not transmit at the proper baud rate. It did manage to connect to the airbag unit though.

-doug

 

So what baudrate does your software want to use? The com port is set up for 9600. Do I need to mess around with the parity, flow control or data/stop bit settings?

My usb-serial converter is a Prolific. I see it has provision for external power input. Maybe I should rather try that instead or relying on the bus power.

 

Laurence,
I think Diagnostic pin 15 goes to pin22 DME . Pin 13 is the ignition switched supply ?

Geoff

 

sure wish i could get one of the interfaces so I could try this
still no email on the interface

 

I emailed Andy Whitaker on Monday and haven't heard back either. I simply wanted to know if he had them in stock - the website sez they're out.

I'm not concerned about the shipping - I can't imagine that air mail to the US would be more than $15-$20.

 

Last week I asked to be on the waitlist. Over the weekend he told me to go ahead and place the order. But there's no way to place an order on a sold out part. I told him this and asked about shipping and haven't heard back.

 

LeRoux,

The software will do the com port setting for you. The Motronic unit uses 8800 baud which is a challenge for the USB/serial converters.

Have you tried connecting to the air-bag ECU? It uses the more common 9600 baud.

-douf

 

Dougb

my car does not have an airbag -

None of the modules connect. I will mess around with it again this weekend with external power applied to the usb converter.

 

It was a long time since i put those markers on the drawing(and i have nearly always used pin 12) so your no doubt right Geoff.Apologies to anyone who was misled. The rest are correct though, i hope.

 

you might want to try this it may help: use hyperterminal (it's in accessories) create a new connection 9600,np,1 stop bit, xon/xoff call it something and the create box will dissappear. and hyperterminal will try to connect to your interface (you'll need a 12v source to power up the interface, computer has some disguised as plugs for hard disks etc!) type anything and it should echo back. Given that your leds are flashing i doubt this will be of use but maybe worth a try.

 

John Speake of jdsporsche (rennlist sponsor) has offered a group buy discount on his 19 way connector. I must confess to having virtually no idea how these group buys work so if anyone does let me know. Basically John is offering the bare connector, housing and pins for £45 + vat and carriage to group buys of five or more.
Given the relatively small numbers that these are likely to be made up in it's unlikely that this sort of price is going to be significantly bettered in the near future.