[RESOLVED] usb logging cable inquiry

[AlaskanDsm]

Why is it impossible to create a logger cable that has a USB end on the cable side that connects to the car? Is there no way to create one that would work with a laptop or possibly be used to connect the USB newer sync cable to the car. I understand that one needs to be a host BUT if you are just using the connecter, What is the difference from using serial re-wire on the sync cable?

Wouldn't this provide easier access for some of the newer palms that are compatible with USB cradles that otherwise might not have a serial counterpart? After all, isn't the serial just another way of connecting 2 bare wires?

 

[twdorris]

Why is it impossible to create a logger cable that has a USB end on the cable side that connects to the car?

For a PC connection, it's certainly possible. Below is one such example.

ECMTuning, Inc.

That's a fully opto-isolated solution in a clean, molded package. One end connects to the laptop, the other to the diagnostic port in the car. As Curtis mentioned above, there are signaling differences (RS232 vs. TTL), but there's also fundamental design issues to deal with. A USB device has to identify itself to the PC in some way that an appropriate driver can be located and loaded up. A simple DB9 serial device doesn't. The solution to both these problems is a simple little FTDI chip.

For connections via a Palm or PocketPC...good luck. The problem there is that USB devices are either "slaves" (devices you plug into a PC for example) or "hosts" (the PC that you can plug stuff into). Cables are slave devices. Palm and PocketPCs are typically slave devices too. Which means you can't plug a typical USB cable into a typical Palm/PPC. There are exceptions, of course. Some PPCs in particular provide a host USB interface and I think it's becoming more common. But I don't think it's "every day" stuff yet by any means.

Thomas Dorris
ECMTuning, Inc.

 

[AlaskanDsm]

As much as that does make sense, what doesn't make sense is if I cut off the USB connector on the sync cable and put a serial port on it it would work just fine. So my question is why can't you just use the USB end that is there and wire the logger cable with a coresponding female connector instead of a serial connector? Is that not the same as connecting 2 serial ports? Its not like I would be connecting the logger cable to the pc. Just want to save the already wired USB.

 

[twdorris]

As much as that does make sense, what doesn't make sense is if I cut off the USB connector on the sync cable and put a serial port on it it would work just fine.

You'll need to explain what you're talking about here. To which situation are you referring? I mean, what exactly are you doing and what are the results? For SURE, cutting off the USB end of a typical USB device and slapping a DB9 connector on it and then plugging that into a PC's serial port instead of the USB port will not work.

Thomas Dorris
ECMTuning, Inc.

 

[AlaskanDsm]

Ok, when I am going to data log, I have 2 cables. My logger cable the goes from the ECU that we have to make using the diode and resistor. Then the second cable is the serial sync cable for the palm that gets plugged into the logging cable.

Now, if I wanted to retain the USB connector for my Plam sync cable, is there no way to just wire up the logger cable half with a female usb connector to get the data across the connection. What would be the difference between using that method and the method where they are both DB9 connectors?

Does that help?

 

[twdorris]

Now, if I wanted to retain the USB connector for my Plam sync cable, is there no way to just wire up the logger cable half with a female usb connector to get the data across the connection.

OK, so you have a USB sync cable for your Palm that you normally use to connect your Palm to your PC. And you'd like to use that cable to connect your Palm to your datalogging cable instead. If so, no, that's just not going to work. The cable you've got there with a USB connector on one end and your Palm connector on the other is actually a USB to serial adapter. Either that or the adapter function is inside the Palm...either way, the USB end must be plugged into a USB host of some sort (PC) that knows how to talk to that device. You definitely can not simply run that USB connector to your ECU's datalogging cable with some simply wire swaps. It's just not at ALL compatible in any way, shape or form.

What would be the difference between using that method and the method where they are both DB9 connectors?

Basically what I've said above. The USB interface requires negotiation and handshaking (host talking to a slave device and vice versa) to establish a communication path of any sort. A straight DB9/RS232 serial connection has absolutely no such concept.

So you have an RS232 device on one end (your ECU) and a USB slave device (the hot sync cable) on the other. There's NO way to connect those two pieces.

Thomas Dorris

 

[AlaskanDsm]

ok that works. I just never fully understood. Thank you for the information and I appreciate the time. I guess I have to wait a while before I can buy the correct sync cable... (so broke). Or wait for Hakcenter's cable which sounds awesome.

 

[twdorris]

Thank you for the information and I appreciate the time.

You're welcome. I think.

Thomas Dorris
ECMTuning, Inc.

 

[Littlebeeper]

so why does the nokia dku-5 cable do a xbox 360 lite-on drive hack. the drive uses the same rs232 communication as the ecu but with the cable and its integrated hardware it is able to read the output of the drive. the serial cable to read the drive is almost identical to the interface cable for the dsm ecu. i am in the process of checking of the serial cable for the ecu will read the output of the xbox 360 drive. if it does that means i would be able to use a usb DKU-5 cable to read the ecu. the only problem i see is finding a program that supports usb as i have not even checked if any obd-1 dsm sofware supports this. i usually just do serial and go. i would hope this works as my new laptops no longer have serial.

 

[Jostar]

For a PC connection, it's certainly possible. Below is one such example.

ECMTuning, Inc.

That's a fully opto-isolated solution in a clean, molded package. One end connects to the laptop, the other to the diagnostic port in the car. As Curtis mentioned above, there are signaling differences (RS232 vs. TTL), but there's also fundamental design issues to deal with. A USB device has to identify itself to the PC in some way that an appropriate driver can be located and loaded up. A simple DB9 serial device doesn't. The solution to both these problems is a simple little FTDI chip.

For connections via a Palm or PocketPC...good luck. The problem there is that USB devices are either "slaves" (devices you plug into a PC for example) or "hosts" (the PC that you can plug stuff into). Cables are slave devices. Palm and PocketPCs are typically slave devices too. Which means you can't plug a typical USB cable into a typical Palm/PPC. There are exceptions, of course. Some PPCs in particular provide a host USB interface and I think it's becoming more common. But I don't think it's "every day" stuff yet by any means.

Thomas Dorris
ECMTuning, Inc.

Will your cable work woth the old TMO datalogging software???

 

[knochgoon24]

Will your cable work woth the old TMO datalogging software???

The ECMLink cable is what costs $595 (give or take a few $$). You can download ECMLink from their site for free if you really wanted to (though you can't log or tune your car with their software without the cable). If you just want to datalog a 1g, you best bet is to either wire yourself a cable, or find someone who's semi-competent with electronics and soldering, and have them make one for you. There are probably other people that make the simple datalogging cable.

Here' are some spiffy kits and cables off eBay if you want to go that route.
1g dsm data log, great deals on eBay Motors on eBay!

 

[snowborder714]

Wes, that was the truth with V2 (the OBDII to serial adapter was the key part of the package). With V3 the chip is now the key, as you can buy a cable from them for $65.

 

[knochgoon24]

Wes, that was the truth with V2 (the OBDII to serial adapter was the key part of the package). With V3 the chip is now the key, as you can buy a cable from them for $65.

Ah. I totally missed that part. V3 came out at the same time I was working on getting my Evo 8 ECU research, information, and installation sorted out. I never really looked into it any farther than knowing it's a big step beyond V2. I give my respect to the ECMLink crew. Their program is sweet. I just decided to take an alternative route, and I stopped keeping up with their package.

Nevertheless, good info to know.

 

[Jostar]

Wes, that was the truth with V2 (the OBDII to serial adapter was the key part of the package). With V3 the chip is now the key, as you can buy a cable from them for $65.

I wanna go USB with the 1g cable, I don't wanna use serial as serial is almost none existent..

 

[twdorris]

I wanna go USB with the 1g cable, I don't wanna use serial as serial is almost none existent..

As mentioned above, our 1G USB cable would work fine for you.

ECMLink USB cable

That's a complete, end-to-end cable with proper opto-isolation on everything (something I don't think any other cable out there provides) and clean molded ends that plug directly in where they're supposed to go.

As for wireless logging, we had that working several years ago but were not happy with the latency at the time so we chose not to develop it further. Hopefully things have improved. Honestly, it ended up not being as cool as I had hoped anyway.

Thomas Dorris
ECMTuning, Inc.

 

[Jostar]

As mentioned above, our 1G USB cable would work fine for you.

ECMLink USB cable

That's a complete, end-to-end cable with proper opto-isolation on everything (something I don't think any other cable out there provides) and clean molded ends that plug directly in where they're supposed to go.

As for wireless logging, we had that working several years ago but were not happy with the latency at the time so we chose not to develop it further. Hopefully things have improved. Honestly, it ended up not being as cool as I had hoped anyway.

Thomas Dorris
ECMTuning, Inc.

Sorry if this sounds dumb, But will the cable will work with the TMO datalogging software???

 

[twdorris]

May I ask why you would even bother with opto-isolation when your cable is overmolded to begin with ? Does it have to do with flashing on the same cable ?

Cable construction has nothing to do with opto-isolation. Nor does using the cable to flash an ECU.

Providing optical isolation inside the cable is primarily a reliability function. By isolating the two electrical systems (the one in the car and the one in the laptop), you eliminate the chance of either system affecting the other.

Thomas Dorris
ECMTuning, Inc.

 

[twdorris]

What is the reason you chose to add such an extraordinary component to a rather simplistic thing, besides decoupling the ultra dangerous output from the ECU to the laptop ?

Your sarcasm is not appreciated nor necessary. I do not feel it beneficial to justify our decisions to you any further on this topic.

Thomas Dorris
ECMTuning, Inc.