RS232 vs USB datalogging with newer Laptop

[nefarious]

I have been researching what I need to be able to run MMCD, Tunerstein, and TMO on my laptop and found most everything goes back to RS232 (DB9).

I am no wiring expert by any means but since I would only be using 3 wires on the DB9 female connector (Data in, Data out, and Ground), I was wondering why I can't use a 4 pin female usb connector like this one: CONNECTOR USB B-FEMALE PCB MOUNT - A-USBSB . According to this website: USB pinout and signals @ pinouts.ru there is a data in, data out, and ground that can be used. That will allow me to connect to my newer laptop (which doesn't have a DB9 connection) using cables I already have laying around the house rather than having to buy a usb to serial cable, install the drivers, etc.

Thoughts?

 

[BoostedTalonTS]

The RS232 is a Serial chipset that is required for logging... True, there are serial emulators that will mimic the RS232 chipset but I haven't had any good results in my experience with them.

I would recommend that you get an old Palm pilot (a Palm 3c is ideal) and use that for logging. IMO, it's A LOT easier then lugging around a laptop any day.

I used to tune with MMCD on a Palm 3c and I liked the idea SO much that now I'm even using it with my DSMLink.

 

[knochgoon24]

I have one of those ELM 327 things they sell on ebay. I'm testing out about a dozen free and demo programs on it right now. I should have a write up with screen shots out sometime soon.

 

[nefarious]

The RS232 is a Serial chipset that is required for logging... True, there are serial emulators that will mimic the RS232 chipset but I haven't had any good results in my experience with them.

I would recommend that you get an old Palm pilot (a Palm 3c is ideal) and use that for logging. IMO, it's A LOT easier then lugging around a laptop any day.

I used to tune with MMCD on a Palm 3c and I liked the idea SO much that now I'm even using it with my DSMLink.

I have already downloaded the Palm Emulator with MMCD, Tunerstein and TunerPlayer, as well as TMO. All i need now is to be able to connect my laptop to my car. Since this is not my dd, carrying a laptop with me when i get around to driving it is not a problem. I would much prefer this over a palm (at least for the moment).

From what i understand Steve the wiseman is pretty knowledgeable about this stuff. Does anyone else know whether or not I can just use the 4 pin female USB jack rather as opposed to the female DB9?

 

[Splitpi]

I have been researching what I need to be able to run MMCD, Tunerstein, and TMO on my laptop and found most everything goes back to RS232 (DB9).

I am no wiring expert by any means but since I would only be using 3 wires on the DB9 female connector (Data in, Data out, and Ground), I was wondering why I can't use a 4 pin female usb connector like this one: CONNECTOR USB B-FEMALE PCB MOUNT - A-USBSB . According to this website: USB pinout and signals @ pinouts.ru there is a data in, data out, and ground that can be used. That will allow me to connect to my newer laptop (which doesn't have a DB9 connection) using cables I already have laying around the house rather than having to buy a usb to serial cable, install the drivers, etc.

Thoughts?

RS232 and USB line signals and communication protocols are completely different. Think of it like this... I speak English only, you speak Chinease only, we have a telephone connecting us, it doesn't mean we can communicate with each other because we are wired to each other.

USB = Universal Serial Bus
Universal Serial Bus - Wikipedia, the free encyclopedia

RS232 = Recommended Standard 232
RS-232 - Wikipedia, the free encyclopedia

They are completely seperate methods of communication.

 

[BoostedTalonTS]

RS232 and USB line signals and communication protocols are completely different. Think of it like this... I speak English only, you speak Chinease only, we have a telephone connecting us, it doesn't mean we can communicate with each other because we are wired to each other.

USB = Universal Serial Bus
Universal Serial Bus - Wikipedia, the free encyclopedia

RS232 = Recommended Standard 232
RS-232 - Wikipedia, the free encyclopedia

They are completely seperate methods of communication.

^^^My point exactly... I was referring to an RS232 chipset emulator, not just a Palm OS emulator (two totally different things BTW). When I was using a USB connection and an RS232 chipset emulator I was able to get it to work... The problem I had was that the data transfer rate was so erratic that it interfered with logging rates. -That's when I abandoned that setup and went over to just using the Palm.

Lets face it guys... These cars aren't getting any younger and the technology that is used to communicate with them is pretty much in the same boat. Using Legacy devices will require a lot less hacking to setup and generally yield better results.

 

[nefarious]

I understand that a RS232 and the Palm emulator are different, I was just mentioning that I have already went to the trouble of downloading all of the software to do the logging on my laptop.

I know they sell USB to serial cables that require drivers to allow the usb to accept the RS232 comm. Is there a way to wire up the necessary components used in one of those cables in my homemade cable?

 

[Splitpi]

I understand that a RS232 and the Palm emulator are different, I was just mentioning that I have already went to the trouble of downloading all of the software to do the logging on my laptop.

I know they sell USB to serial cables that require drivers to allow the usb to accept the RS232 comm. Is there a way to wire up the necessary components used in one of those cables in my homemade cable?

RS232 and USB line signals and communication protocols are completely different. Think of it like this... I speak English only, you speak Chinease only, we have a telephone connecting us, it doesn't mean we can communicate with each other because we are wired to each other.

Yes you can wire it together. Yes its easy to map the 3 wires as you said. No it will not work like that for the reasons mentioned above. The USB protocol is vastly different than RS232.

 

[nefarious]

I now understand that it is not as simple as "plug and play" but what I am wondering is whether or not it would be worth the trouble to "build" the RS232 to USB converter in my homemade cable...something like this: RS232 serial to USB converter cable schematic pinout and signals @ pinouts.ru

The more I research, the cheaper that $35 USB to serial cable at RadioShack sounds

 

[dsm-onster]

Lazarus, Rise!

I may be having problems with my setup or something. But I have a RS232 output on my scanmaster. I liked tunerstein and my laptop only has usb inputs. I have DSMLink for my car but I wanted to log my brothers car with my laptop. As I like it much better than a palm too. Clear screen. And I ahve all my research and various calculators right there. Basically my entire dsm library, all manuals, and wireless internet. So I used the keyspan adapter, which works flawlessly with dsmlink, to go from a serial output from the scanmaster which is rs232 equipped and tried to log with my laptop. Nothing happened. . . Just my experience. I just wonder if this worked out for the OP. . .

 

[knochgoon24]

UPDATE ON THE CHEAP ELM327 LOGGER OFF EBAY

It uses the RS327 chip that is supposedly faster. Since I'm too cheap to buy any software yet, I've just used the free stuff. The only one that I've found to work good with it is wOBD. It's not fast by any means (4 data points / sec) but it does get the job done with a basically stock car.

My verdict... great for reading CELs but keep looking. It's slow as hell and leaves you looking for another option.

There is hope though... I emailed the guy that wrote wOBD and asked him if he was planning any updates. He said he was and that one of them would be the to make the sample speed adjustable. There's a slider in the current version, but it doesn't do anything. I just email him 5 minutes ago after reading this thread asking if he'd send me the source code, so we'll see.