Sorry..my english is not well..

but i really want to know how can I do to increase the communication speed of CAN...

I tried can ferquency 125kps 500kps 1mps....but have not changed at all...

What exactly have you tried? The CAN.fruqency() function? And how do you know the frequency hasn't changed.

I'm using an LPC1768 and looking for some advise on setting up and using the CAN ports for a CAN data logger. There will be two CAN ports with incoming data at 500K and 125K. I need to grab all messages on both ports and log the data to an SD Card. I have the SD card read/writes working.

My question is about the best way to setup CAN. From reading the user manual, I'm not getting a good feeling for how to setup the CAN system.

It seems that the LPC1768 only has a Rx CAN buffer of size 2. I'm afraid that I will miss some messages when writing to the SD card. I also see that there is a Full CAN mode. It looks like in this mode an Interrupt is generated when the CAN buffer is full. Will this cause me to potentially interrupt the SD card writes.

What is the best CAN mode to use for this type of application? Is there any recommended reading or sample code.

Thanks.

Even I am interested

There are a great number of CAN discussions on the site, and you will find many code samples as well.

Related to the file system, I'll point you to one thread on performance with data from a simple and not very scientific experiment I did.

And for CAN you might find these helpful.

• The Handbook has a CAN page.
• There is hardware information/schematics and Software. The software probably has a lot more stuff in it than what you want. The CAN libraries have been updated since that code was put together, so you might also start with looking at the lib functions and building up from there.
• CAN in automotive - OBDII
• And for CANopen

Unfortunately, "CAN" is pretty generic for the search engine, but you can also try CANBUS and find quite a few samples.