FDCAN no ACK

[Adam_Stastny]

Hi,

I am trying to use a STM32G491KEU6 with FDCAN, but the communication is failing at line:

if (HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan1, &TxHeader, TxData) != HAL_OK) { ...

I found out that this is a problem that receiver is not sending a ACK bit - cannot it be a software issue? I am using two STM32G491KEU6 with the same code mentioned bellow, while I am also using a TCAN3403DRBRQ1 transceiver on both boards.
The boards seems ok, I can even see a transmittion on the line with oscilloscope, but there is probably no ACK.

Thank you for any help

[SofLit]

Hello,

For CAN/FDCAN subject especially when using Normal mode you need to provide more details especially the HW part. So please share schematics.

Also, I recommend to use HSE with an external crystal instead of HSI.

As per your code:

RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;

[Adam_Stastny]

I am sending a schematic. In my PCB, there is also a GND on pin 8 STB (by datasheet, this should allow normal mode instead of standby mode).

Thx for that recommendation.

[SofLit]

Hello,

Could you please share your ioc file?

Chenge FrameFormat to FDCAN_FRAME_CLASSIC;

Could you also please states on Y1? could you please share its datasheet?

[Adam_Stastny]

Yeah, no prob.
Y1 should not be the issue - I am using a classic CAN with the same Y1 and STM32F446RET6 and it works as it should.

Datasheet: https://cz.mouser.com/datasheet/2/122/ecx_53b-3074848.pdf