UNO R4: Add support for CAN Standard Frame Format (in addition to EFF)

[srolf]

Please add in the UNO R4 CAN library the support for transmit/receive of CAN frames also in SFF.

Preferred would be an own parameter in the message creation which allows to define either SFF (maybe the default) or EFF.

Adding a hint towards the current CAN tutorials would be helpful, because it's not directly obvious to be forced/limited to EFF.

CAN 2.0A defines SFF.
CAN 2.0B defines EFF.
Most of the available MCP2515 libs are supporting SFF and EFF.
CAN on Arduino Due by "due_can" lib supports SFF and EFF.
In the automotive area SFF for communication is very common.

[aentinger]

Your feature request(s) has been noted. I'll try to get some time scheduled for extending software-support for 11-Bit IDs.

[srolf]

Your feature request(s) has been noted. I'll try to get some time scheduled for extending software-support for 11-Bit IDs.

Thank you very much!

Out of curiosity: Maybe not possible, but I'm wondering if the CAN TXD/RXD pins can be remapped or are they "hard-wired"? Background: I was thinking about using a Minima and the Ethernet Shield Rev2 to create a gateway CAN<->ETH. But without remapping, I would expect issues with the SD-card reader on that shield.

[aentinger]

Maybe not possible, but I'm wondering if the CAN TXD/RXD pins can be remapped or are they "hard-wired"?

They can also be remapped to (some) other pins, the key is to search pinmux.inc for PIN_CAN_TX and PIN_CAN_RX. However, as the CAN objects are instantiated in the library (i.e. here) you'd need to change the library to change the pin-mapping.

[aentinger]

Heads up everyone, mixed mode (supporting both 11-Bit standard CAN IDs and 29-Bit extended CAN IDs) is now being supported for Arduino Uno R4 WiFi and Minima. If you want to take a sneak preview take a look at #79 .