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CAN-FD using MIMXRT1064-EVK and PCAN-View PC software

Question asked by Paul Roberts on Nov 25, 2019
Latest reply on Nov 26, 2019 by Paul Roberts

CAN-FD using MIMXRT1064-EVK and PCAN-View PC software & CAN-FD adapter from Gridconnect, MCUXpresso version 11.

 

The symptoms:  I cannot communicate to the PC from my eval board using CAN-FD, only basIc CAN.  The PCAN-View software reports a bus error when I send a message from my i.MX 1064 eval board.

 

My findings thus far:  I'm transmitting a message from my MIMXRT1064-EVK eval board to my PCAN-View software via the Gridconnect USB adapter.  The messages is CAN-FD with Bit Rate Switch Enabled.  The node Id is 0x321 Standard, payload size is set to 8 bytes, nominal bit rate is 1 Mbps, data bit rate is 2 Mbps.  The payload bytes are (in hex)  55 aa cc 33 77 88 11 ee. 

 

PCAN-View does not like what it sees, as it reports a "Bus Passive" error.  I tried transmitting exactly the same message from PCAN-View back to the MIMXRT1064-EVK in order to compare waveforms.  The waveforms are different, and the difference appears to be in the CRC section.  Following the payload, the MIMXRT1064-EVK appears to send out the bit pattern 1001101000100010010100010, whilst PCAN View shows 111001000100110111010.  It appears that MIMXRT1064-EVK is using CRC21 vs CRC17, which is what I believe I may be observing from my Gridconnect adapter, based on the different number of bits observed (different by 4 bits) in one vs the other.  The question is why.

I'm running the evkmimxrt1064_canfd_interrupt_transfer example.

Any suggestions are welcome!

Paul

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