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Silvy · 11-24-2006, 01:19 PM

I'm trying to get to grips with collecting vehicle performance data.

The company I work for has performed analysis on such data in the past and is looking for the way to collect that data (vehicle speed, fuel consumption and such).

I've read up on the (E)OBD (I/II) standards. I've looked at some OBD-II scantools. We've worked with a CAN converter before...
Some questions remain however:

- What is the relationship (technology-wise) between OBD-II and CAN?
(I gather from tha intarweb that OBD-II is a request-answer protocol whereas the CAN bus can have broadcasting elements in addition to a question-answer system). Is the CAN bus just a main databus in the car, on which the (required) OBD-II plug is just a filter?
Or are they two separate ways of sending data through the vehicle?

- Is there a CAN-standard similar to OBD-II for which vehicle data is transferred? Is there a standard CAN-plug definition?

- Can you give me some pointers/opinions on hardware solutions for accessing basic vehicle metrics like vehicle speed, fuel consumption (such as provided by OBD-II).

The idea behind this is creating a manufacturer-independent on-board recording unit for basic vehicle data. OBD-II appears to be most commonly available, but from experience we know that the CAN bus on recent vehicle models contains a lot of interesting messages. So while OBD appears sufficient for now, if a CAN solution is feasible then it might be more interesting.

As I said, we've worked on the data before, and we've developed on-board hardware/software before. We've just never used that hardware to collect that data.

Right now I'm looking at some bluetooth OBD-II connectors that hopefully we'll be able to connect to and read with our current hardware (which is BT enabled).

11-24-2006, 01:19 PM	#1 (permalink)
Silvy paranoid Location: The Netherlands	request info on OBD II / CAN I'm trying to get to grips with collecting vehicle performance data. The company I work for has performed analysis on such data in the past and is looking for the way to collect that data (vehicle speed, fuel consumption and such). I've read up on the (E)OBD (I/II) standards. I've looked at some OBD-II scantools. We've worked with a CAN converter before... Some questions remain however: - What is the relationship (technology-wise) between OBD-II and CAN? (I gather from tha intarweb that OBD-II is a request-answer protocol whereas the CAN bus can have broadcasting elements in addition to a question-answer system). Is the CAN bus just a main databus in the car, on which the (required) OBD-II plug is just a filter? Or are they two separate ways of sending data through the vehicle? - Is there a CAN-standard similar to OBD-II for which vehicle data is transferred? Is there a standard CAN-plug definition? - Can you give me some pointers/opinions on hardware solutions for accessing basic vehicle metrics like vehicle speed, fuel consumption (such as provided by OBD-II). The idea behind this is creating a manufacturer-independent on-board recording unit for basic vehicle data. OBD-II appears to be most commonly available, but from experience we know that the CAN bus on recent vehicle models contains a lot of interesting messages. So while OBD appears sufficient for now, if a CAN solution is feasible then it might be more interesting. As I said, we've worked on the data before, and we've developed on-board hardware/software before. We've just never used that hardware to collect that data. Right now I'm looking at some bluetooth OBD-II connectors that hopefully we'll be able to connect to and read with our current hardware (which is BT enabled). __________________ "Do not kill. Do not rape. Do not steal. These are principles which every man of every faith can embrace. " - Murphy MacManus (Boondock Saints)