Hello everyone,

what is the maximum CAN frequency? Is it 1MHz? I would like to connect two mbeds via CAN bus.

Edited:

A 1 Mhz bit-rate is the fastest that CAN is rated. I haven't studied the configuration on the LPC1768 to see if it could be programmed to exceed that speed. I think 10 kb/s is the low end, and some transceivers can't go that low.

Note that most, but not all, of the commercially available CAN transceivers are rated for 1 Mb/s. There is a lower-speed transceiver that has additional diagnostics, but I think it is only rated for 125 Kb/s. Many of the baseboards listed on this site have CAN transceivers - you might want to study the schematics for them.

Here's a short sample of transceivers. There's nothing special about this list, and you'll find parts differ in speed, power consumption, diagnostics, voltage tolerance, signal wave-shaping, silent-mode, and more:

• Infineon TLE6255G: Low speed single-wire up to 33kb/s, high speed mode up to 110 kb/s
• On Semi NVC7341: High speed up to 1 Mb/s
• NXP TJA1050: High speed up to 1 Mb/s
• NXP TJA1054: Low Speed up to 125 kb/s
• Atmel B10011S: Low speed up to 1Mb/s
• Microchip MCP2551: 1Mb/s

As you see, even the definition of speed isn't consistent.

Thanks for the reply David. It would be good if this information about the speed of CAN, Serial etc would be on the Handbook webpages.