Hardware of Classical CAN bus on Nucleo-H755ZI dual chip only support CAN FD

[ManhPham]

Hello everyone, I'm using classical CAN bus mode on Nucleo-H755ZI dual chip (this board only support CAN FD), I chose CAN FD at Classical mode.

I want to ask about hardware, may I use the external module CAN transceiver MCP2551 for classic CAN bus or I must to use module MCP2562FD of CAN FD?

Note: I just need classical CAN bus on STM32 dual core, not CAN FD.

[AScha.3 · Accepted solution]

Hi,

if you anyway not use CAN FD , you dont need hi speed CAN transceiver , so MCP2551 for classic CAN bus is ok.

[ManhPham]

I tested CAN FD classic mode with MCP2551, but it is not working. If hardware MCP2551 correct, it means my code wrong? Isn't it?

[mƎALLEm]

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@ManhPham wrote:

I tested CAN FD classic mode with MCP2551, but it is not working. If hardware MCP2551 correct, it means my code wrong? Isn't it?

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If the HW is ALL OK, there is an issue in the code, it depends on the issue, issue on Tx, on Rx?

Meanwhile you can confirm this this in loopback mode mainly to test your Filters config. If all is OK in loopback mode, and in normal mode is not OK, I can suspect mainly two issues:

1. HW issue: transceivers, wiring, terminating resistors etc ..
2. Software/config issue:

• Bitrate config
• Clock source selection (needing HSE with a crystal, or any external accurate clock source in Bypass mode)