STM32F74G-DISCO and STM32f407VGT6 with CAN bus communication not working

[PAra.1]

Hello,

I have two boards: STM32F74G-DISCO and STM32f407VGT6 

They are connected with CAN bus, but the connection is not working. On the picture in attachment is my schema. I think that my code is okay, but I am not sure about schema. I have two transceivers MCP2551. I can paste also the code, if needed.

Thanks for answers.

[Tesla DeLorean]

Common the ground on the F746 side

[PAra.1]

I have tried it, but the same result. Both boards are also connected to the same PC, so there should not be the problem with ground.

[Nikita91]

According to the MCP2551 datasheet, the driver may be in standby mode: V Rs > 0.75 VDD

See table 1-1

Rs pin must be tied to ground through a resistor

[PAra.1]

I changed transceivers and used new ones: MCP2542. Now it is working fine.

Thank you very much for your answers.