Hello, I am trying to communicate between 2 STM32G4 using FDCAN. Using Test Modes it works without a problem. When i change to Normal Mode, TX and RX dont work.

[LAzev.1]

Hello, I'm trying to build a simple program to communicate between 2 microcontrollers using FDCAN. Im not using a transciever yet, just connecting TX of one Nucleo-G431KB to the RX of one Nucleo-G474RE, and vice-versa.

Using the test modes, External Loopback and Bus Monitoring, i can send and receive data without a problem. Filters works properly, everything seems ok.

When i switch to Normal mode, i can't send and/or receive data.

I tried using an osciloscope on the sender TX, and i dont get any signal, when in normal mode.

I'll post the code of the sender, and receiver.

Can someone help me? What am i doing wrong?

[SKacp.1 · Accepted solution]

Hi,

Please set corretly NominalTimeSeg1 and NominalTimeSeg2 also set the same FrameFormat. Please see post:

https://community.st.com/s/question/0D53W00000j5m6SSAQ/stm32-can-bus-not-sending-the-messages

https://community.st.com/s/question/0D53W0000080SyvSAE/get-no-coomunication-via-fdcan1-on-stm32g431rb-nucleo-board

https://community.st.com/s/question/0D53W00000iEGAOSA4/helloi-am-trying-to-set-up-a-fdcan-communication-std-id-at-a-baud-rate-of-250-kbits-in-stm32g473rbt-the-tx-part-seems-to-work-perfectly-but-i-have-a-problem-at-the-level-of-the-reception

http://www.bittiming.can-wiki.info/#bxCAN

If You use Normal Mode please use externa transceiver for CAN.

Best Regards,

Slawek