I’ve bought a ELM-USB from obdtester.com. It interfaces the OBC-II bus found in just about all recent cars into a serial port over USB.
Inside the case there are two circuit boards: One marked “Generic OBDII Board” and one marked “FoCOM K-USB ELM-USB”. A pretty (an scaled on the client-side ;)) picture of the parts:
ICs on the usb board:
- PIC18F 2455-I/SO, 0823V9Q
- MCP2515 “second generation stand-alone CAN controller”
- A82C250 (CAN controller interface)
- 78L08A 8v voltage regulator
- 9241A 4x potentiometer
One 160000M crystal.
As found on: http://www.obdtester.com/elm-usb.
The OBC2 interface, or at least the protocol presented by the ELM- USB, seems easy. Slightly Hayes-inspired, start with ATZ and then 01xx\n to read sensor data.
Why? No plan. Just wanted to see what that strange looking port in my car was good for.