So, I've got an issue with my FBH on my 05 RRS but luckily I already have the red wire through to pin 7 on the OBD-II interface and the Webasto software. I started looking for a USB interface with K-line support (or KKL) and can find a couple aimed at the Audi/VW.

If I just wanted CamBus then there are hundreds of ELM327 knock-off Chinese versions out there - all running the original ELM327 v1.0 code and pretending to run higher due to it being ripped before code protection was enabled in v1.1+

My question is, can anyone recommend an OBD-II to USB or Bluetooth interface that can run both CamBus and K-line for a reasonable price with a real ELM (v1.4b+) or STN1110 chip? It'd be nice to have just one interface for both jobs with a proper chipset.

The ELM327 datasheets show that the chips can be interfaced to both CamBus and K-line (and J1962) and I'm quite happy to knock up a PCB to do it if I have to - but it's a question of time and money. The new v2.0 ELM chip retails at about $23 so anything significantly cheaper must be a crap clone. I may just knock this up anyway for fun as it'd still be cheaper than a pro unit...

'tang

Ok, so I discovered that even the latest true ELM/STN based units can't read or write the K-line in RAW format so can not be used to communicate with the W-bus FBH.

See this thread for a better explanation: http://www.rrsport.co.uk/forum/topic31997.html

As per all the other threads around the web, any OBD-II ELM/STN based interface for less that £20 GBP is likely to be a crap clone - either buy direct from a good reseller or build your own That's not to say that anything you find on the web over £20 is real either.

The chips themselves cost £15 GBP (ELM327) and £11 GBP (STN1110) - or only $10 USD (£7 GBP) if you're happy to buy from the USA.

If you're going to build-your-own then I'd recommend the STN1110 as on paper it seems to outstrip the ELM327 chip across the board. If you want the STN1110 plus single wire CAN and Medium speed CAN then go for the STN1170.

ELM327: http://elmelectronics.com/obdic.html#ELM327
STN1110: http://www.obdsol.com/stn1110/

Disclaimer: I don't have any connection with OBD Solutions or ELM Electronics other than existing on the same planet and have had no prior dealings with them. All pricing shown was found from a quick web search which can be as reliable as a 1984 Fiat X1/9.

'tang.