No CAN Communication on STM32H723ZG-E01 (A230801274)

[mani9989]

Dear STMicroelectronics Support,

I am working with the STM32H723ZG-E01 board (Serial: A230801274) and encountering an issue where CAN communication is not functioning as expected.

Based on the documentation, I have configured the FDCAN1 interface to use PD0 (FDCAN1_RX) and PD1 (FDCAN1_TX). The FDCAN peripheral clock is set to 20 MHz. The external transceiver is correctly connected and powered, and the rest of the board appears to function normally.

Despite this setup, no CAN or CAN FD communication is taking place. I would appreciate your help with the following:

1. Could you please confirm whether PD0 and PD1 are valid and officially supported pins for FDCAN1 on this specific board?

2. Are there any known limitations, errata, or special configuration requirements for using these pins?

3. Could you kindly share a sample .ioc configuration file and example code (bare metal or HAL-based) for basic CAN or CAN FD communication on the STM32H723ZG-E01 board?

This would greatly help us verify our setup and ensure we're not missing any critical configuration steps.

Thank you for your assistance.

Best regards,
Kasani Manikanta 

[Tesla DeLorean]

Sorry, which board? The NUCLEO-H723ZI ?

Download a schematic from the "CAD Resources" tab on the product page, check the pin wiring for the pins of interest to determine if there are any immediate and obvious conflicts.

For canned example, perhaps look at some of the STM32H7 EVAL/DISCO series boards, which come prepopulated with CAN hardware. Should be some in the CubeH7 example trees.

Direct support should be sought via your local sales rep or FAE (support engineer)

Also consider using the Online Support system.  https://ols.st.com/s/

[mani9989]

The board is NUCLEO-H723ZG. 

I checked their no example for CAN of the NUCLEO-H7xx boards.

[mƎALLEm]

Hello @mani9989 and welcome to the community,

Please reveiw that article: STM32 FDCAN running at 8 Mb/s on NUCLEO boards

NUCLEO-H723ZG is not available as example on the article (Github hotspot link) only NUCLEO-H753ZI is supported. But you can easily port the example from STM32H753 to STM32H723. The example is already using PD0 and PD1 GPIOs + STLINKV3-MCO output as clock source for the system clock. Refer also to this article: How to use STLINK-V3 MCO output on Nucleo boards as a precise clock source for STM32

Hope that helps.

 

[mani9989]

WIth the terminator resistor it works. I can now see the Transmission. 

But I dont see the reception. I am sending the can frame and dont get the inteerupt hit. ANy idea what can be the problem. 

[mƎALLEm]

Hello,

Please be more specific and provide more details. We cannot help you if you don't share enough information with us:

1 - Please provide a clear sketch of the complete CAN bus: the two nodes + their transceivers + the two terminating resistors.

2 - Share your project, a minimal but with a complete software that can be run from our side.

Without the requested information, I cannot help you further.

Thank you for your understanding.

 

[mani9989]

Thanks for your support @mƎALLEm  & @Tesla DeLorean   - I got the RX interrupt running. 

Can you please let me know the clock settings I am using are correct. I have attached the ioc file here. 

We will soon work on ADC, SPI & I2c.

[mƎALLEm]

What about the Hardware and the sketch? I cannot go further with you if I don't have a clear view of your hardware. 

So please provide a complete view of your CAN bus.

I've attached the ioc file with the correct settings in RCC section.

Did you check if you have 5MHz at the output of STLINK V3 like described in the article How to use STLINK-V3 MCO output on Nucleo boards as a precise clock source for STM32 / section 2. How to get MCU target HSE fed by STLINK-V3 MCO with an accurate clock source ?

 

[mani9989]

Hello @mƎALLEm ,

 

I have attached the HW sketch and the IOC file. 

Can you please let me know if the clock settings are right. 

I am looking for can clock 8Mhhz

BR

Mani

[mani9989]

hello @mƎALLEm 

Yes you  are coorect. So you go the picture of the setup.

CAn you check ioc for the clock config where I am looking for can clk with 8Mhz and Input Freq 24Mhz

[mƎALLEm]

No. You need to use 5MHz as Input frequency as I shared in the ioc file I've attached previously. You don't have any 24MHz source on the board. If you need your system clock set to 24MHz with a 5MHz as HSE input, this is the right configuration:

And you need to check if the STLINK-MCO is set to output 5MHz as stated in the article: How to use STLINK-V3 MCO output on Nucleo boards as a precise clock source for STM32