another cable question

[greggbruceauto]

with what you want to do, you're not going to find many ready-made solutions... reason being that almost everything using a DB9 connector is going to be a RS232 implimentation.... assuming the end of your cable that already exists is just a cable(no MAX232 circuit or something similar in it to convert RS232 to TTL/UART), then a RS232 converter won't work and would likely damage the PCM if it were attempted to be used.

what is MAX 232 -- this is the first it has been brought up.... I thought you said 'FT232' -- how does that differ from RS232?
I posted the links at the beginning of the thread -- the aldl cable I have was the standard when laptops still had serial ports. It was specifically made to use with OBD1 -- I find it difficult to believe it is such a rare bird now (and they still sell it brand new) since usb has become so popular .....that was the cable 'they' all said to use at the time --- how can it be it is so difficult to make that data enter into a newer computer -- they all still use windows, and they all still only understand 1's and 0's --- and it's STILL the same stream of data it was 14 years ago..... today's computers still understand touchtone phone sounds.... those have been around since the 70's .....and now they even have USB record players....

[jim_in_dorris]

I think what you really want is a OBD1 to usb cable. Robert is being modest, he builds and sells one on this forum at a very reasonable price.

[EagleMark]

http://www.gearhead-efi.com/Fuel-Inj...uy-ALDL-Cables!

and helps the more electronic type geeks build them from cheap china parts...

http://www.gearhead-efi.com/Fuel-Inj...USB-ALDL-Cable

On the home page of ALDL cables it says "If you have an ancient laptop that does not have a USB interface, buy our Serial ALDL Cable"

Just as you would buy 8 tracks if that was the media player you had...

There's tons of parallel cables at thrift stores too! But nothing left to use them on... I even see floppy disks brand new for sale, whens the last time you saw a computer with that?

I remember having one of those cables and when I got a newer laptop used at a garage sale because it was old... it didn't have serial, so I got a converter cable like yours and spent WAY to many hours and bought WAY to many other adapters but did get it to work, I think it was my first windows 98 PC, wish I could remember how, that was so long ago, before gray hair!

From the prices of USB to serial adapters with FTDI chip your almost at buying price of a new USB cable.

Buy a cable and get on with life and your car! Sell the old serial one on eBay as a very rare antique collectible Tuner cable!

[RobertISaar]

i went and reread this thread....

since you already have the ALDL to RS232 cable, you'll want a USB to RS232 adapter that uses a FT232R chip to do that conversion. the first one that comes to mind that i know works is the Parallax 28030/28031, i used quite a few of those with excellent results before i jumped up to USB to TTL/UART converters.

note that the 28030/28031 is just the populated board, there is no enclosure of any kind. i think the cheapest source i ever found was directly from parallax.

as far as something that is mostly essentially self-contained, there is this:

http://www.ebay.com/itm/USB-FTDI-FT2...9463%26ps%3D54

it looks to be what you're looking for.

[Six_Shooter]

what is MAX 232 -- this is the first it has been brought up.... I thought you said 'FT232' -- how does that differ from RS232?
I posted the links at the beginning of the thread -- the aldl cable I have was the standard when laptops still had serial ports. It was specifically made to use with OBD1 -- I find it difficult to believe it is such a rare bird now (and they still sell it brand new) since usb has become so popular .....that was the cable 'they' all said to use at the time --- how can it be it is so difficult to make that data enter into a newer computer -- they all still use windows, and they all still only understand 1's and 0's --- and it's STILL the same stream of data it was 14 years ago..... today's computers still understand touchtone phone sounds.... those have been around since the 70's .....and now they even have USB record players....

The problem is not the ALDL cable, or even necessarily the USB to serial cable, it's the way Windoze enumerates the port, and sets com speed (baud rates). The PC is looking for a certain rate of data exchange. With the non-standard buad rate of the GM ECM, trying to communicate with the USB to serial converter, sometimes packets get missed in either direction, and a loss of communication happens.

The only way to almost guarantee that the ALDL cable you have works is usually to buy a very expensive USB to serial adapter, which will be almost as much if not as much as buying a new USB ALDL cable.

There are other ways, as Robert is suggesting, to find specific converter chips, that you may be able to find at cheaper prices, but then you still have extra connections, as in the adapters, the power port plug, etc.

I am also part of the group that tried to make a serial ALDL cable work with a USB converter, without success. I made a MAX232 based ALDL cable years ago, that works with any native serial connection, in fact I still use it frequently with my test bench, since my desktop PCs have had native serial connections for a while now, or through the use of a PCI serial card. I gave up pretty quickly, and just bought the moates ALDL Xtreme about 8 years ago, and have never had an issue with it. I have used it on MANY cars over the years without issue, at least no issues that weren't user created. ;)

[greggbruceauto]

I think what you really want is a OBD1 to usb cable. Robert is being modest, he builds and sells one on this forum at a very reasonable price.

yeah, asked him -- says he is waiting on parts

[greggbruceauto]

From the prices of USB to serial adapters with FTDI chip your almost at buying price of a new USB cable.

Buy a cable and get on with life and your car! Sell the old serial one on eBay as a very rare antique collectible Tuner cable!

That's the direction I'm leaning towards now.....

[greggbruceauto]

A BIG thank you to

http://www.ebay.com/itm/USB-FTDI-FT2...9463%26ps%3D54

it looks to be what you're looking for.

for that link, I got it in the mail yesterday, and finally after figuring out the 12v cig lighter adapter on the cable has to be plugged in, and the 10k jumper has to be set, I FINALLY got a datastream !!! Without the 10k, it gets data, but all the values cycle from min to max over and over, and it gets errors, and sometimes the "DA Connected" turns red....

I just captured about 15 second stream in the driveway, I'm going to open it up and fiddle through it, and then get a whole trip (30 min or so) this weekend maybe...

Looks like I'm on to the next steps...

Thanks again to all for the help -- I know this is a learning process, I'm glad I have all you teachers out there....

[EagleMark]

Don't think you ever told us what ECM/vehicle/mask? But some just need 10K to start data flow...

[greggbruceauto]

Don't think you ever told us what ECM/vehicle/mask? But some just need 10K to start data flow...

sorry, it's a $6E, 1227165 89 F body TPI

[EagleMark]

Pretty sure that is just 10k to start.

Also beware that ECM is known for loosing a connection...

[greggbruceauto]

Pretty sure that is just 10k to start.

Also beware that ECM is known for loosing a connection...

yeah, I think I noticed that, every few seconds or so all the data would max/min out --- you can see it in graph mode....

I just hope it's not going to be the case from now on...

this car is for my non -gear head middle son, as long as it drives, he don't care.

If it was a car of my own I was going to keep and continue to modify, it looks like from your response, I would look at changing to something different?