I would like to get a second connector so that I do not have to disconnect the PC interface when leaving my car on service. Where can I buy one?
The car connector and the USB interface. (without USB cable)
the cheapest place would be a junk/scrap/salvage yard. bring some wire cutters and chop a connector off another car.
If you want to buy brand new, then there are several online stores that sell them including carplugs.com and [the already mentioned] obd2cables.com
P.S. -as amazing as it sounds, if you for "OBDII connector" in google, it actually results in places to buy them. incredible!! (j/k... sorry, but I had to poke fun at your laziness )
Yes, it was a bit on the lazy side I guess. It's difficult when you are new to something and don't know where to start. Hopefully I'll find a splitter on these links that will fit right into my E46.
Going from lazy to overambitious
I paid €90 euro for my ELM323 OBDII adapter.
Now I found a drawing of an interface from OBDII to RS232 on internet:
Apart from the fact that this is not RS232 :-) I expected a little more than an electrical converter at €90.
Is there someone who's made adapters like this and are selling them? Is there a market for such an adapter?
I have a BMW E46 that supports ISO14230 / ISO9141 / KWP2000 (keyword protocol)
That only works if you have the ISO 9141-2 (iirc) standard, which IS actually a serial based interface. Sure there would be a market, for the few how have ISO-9141-2 and the capability of operating their serial port at such a low baud rate (5bps) for the init message.
The ELM323 is not just an electrical converter, it's a microprocessor which converts different protocol OBD messages to serial, so you can communicate with your car. It handles the initalization and headers so you don't have to. Also it allows you to talk to ISO14230 and KWP2000 cars since they are not serial-type interfaces
I was looking for the interface of ISO14230 and found referencies to ISO9141. I thought that they were more or less the same. (obdii pinout)
Did you mean I2C with "iirc"? Seems very much like a 12V IIC or IBus electrical interface. Has it similar collision detection?
So ELM323 does a few more things... Maybe someones written a driver to do the same in sw? I was thinking that I could build that ISO9141 single wire interface with a USB FTDI chip on and loose the bulky/expensive OBDII interface.
Or maybe I should try and source the ELM323 chip :-)
What do you think?
I mean "If I Recall Correctly" by (iirc)
Read that, it seems that ISO14230 k-line communication operates in the same way as ISO9141, my bad.
Personally I'd source an ELM323 chip, let the micro do the processing so your computer dosent have to. Can computer serial ports even go down to 5 baud for the slow init if you need it?
That drawing has -12V as it should making it rs232!
I don't know if it works, but the terminal emulator of my choise, Realterm, accepts 5 as baudrate!
Tried to find the ELM323 at a distributor but could not. So, I'll forget it. Thanks for the insites though!
(turns out I paid a lot to much for my interface.... 30USD on ebay is more like it...)