CAN communication between 3 Nucleo boards

[Srivatsan]

Hi,

I am trying to establish CAN communication between three different MCUs: NUCLEO-H723ZG, NUCLEO-H755ZIQ, and NUCLEO-G474RE. However, I am unable to successfully communicate between the boards, even though the same baud rate has been configured on all MCUs. I have also connected an external CAN transceiver to each board for proper CAN bus operation.

On the NUCLEO-G474RE, I have enabled UART4 to send command data, using the following pins:

• PC11 – UART4_RX

• PC10 – UART4_TX

Clock Frequency [SYSCLK] & Baud Rate [CAN]:

1. NUCLEO-H723ZG: 550 MHz

    Baud Rate: 500000 Bit/s

2. NUCLEO-H755ZIQ: 480 MHz

    Baud Rate: 500000 Bit/s

3. NUCLEO-G474RE: 170 MHz

    Baud Rate: 500000 Bit/s

[LCE]

> That's a bad configuration.TSEG1 =TSEG2 = Tq!

... and giving an interesting nominal bit rate of 5 Mbit/s :D

Which might be an interesting experiment if the STM32 can handle this. But TDC should be enabled.

[mƎALLEm]

---

@LCE wrote:

... and giving an interesting nominal bit rate of 5 Mbit/s :D

 LOL! nice catch. I didn't notice that. I saw it 500kb/s.. Classic mode @5Mb/s :D

[Ben11]

Murged threads for the same subject..

Hi,

I have connected three MCU boards on a CAN bus with proper termination using two 120 Ω resistors at each end of the bus, resulting in an effective bus resistance of approximately 60 Ω. The grounds of all boards are connected together.

The three boards used are:

• NUCLEO-G474RE (2 boards)

• NUCLEO-H723ZG (1 board)

Each MCU board is interfaced with a TJA1050 CAN transceiver for CAN communication.

Hardware setup:

I am using STM32CubeIDE version 1.19.0 and have flashed the CAN firmware onto each board. An external CAN bus monitor/analyzer is connected to observe the CAN traffic.

I am able to successfully monitor CAN data from the two G474RE boards (the data is attached below), but I do not see any CAN messages from the H723ZG board on the bus monitor.

All boards are configured with the same CAN baud rate of 500 kbit/s.

CAN Identifiers Used:

• G474RE Board 1: 0x123

• G474RE Board 2: 0x124

• H723ZG Board: 0x125

Clock configuration:

G474RE (2 boards):-

SYSCLK: 170 MHz
FD CAN :170 MHz

H723ZG (1 board):-

SYSCLK: 550 MHz 
FD CAN : 137.5 MHz

Bus Monitor Data:

Pins details:

NUCLEO-G474RE:

PA12 - FDCAN1_TX 

PA11 - FDCAN1_RX

NUCLEO-H723ZG:

PD1 - FDCAN1_TX 

PD0 - FDCAN1_RX

How you establish the communication in the H723ZG board?

[mƎALLEm]

Hello,

I think this post is similar to this one. 

Are you colleagues? if yes, please avoid duplications and continue in the same discussion. We already provided you answers there!

[Ben11]

No. I need some guidance to resolve the issue. Could you guide me to resolve it ? 

[mƎALLEm]

What do you mean by "No"?

It's the same thread. So please clarify..

[Ben11]

sorry for the inconvenience made. I just now clarified with this. We'll make sure to avoid duplications. 

[Srivatsan]

sorry for the miscommunication made

[Srivatsan]

I have connected three MCU boards on a CAN bus with proper termination using two 120 Ω resistors at each end of the bus, resulting in an effective bus resistance of approximately 60 Ω. The grounds of all boards are connected together.

The three boards used are:

• NUCLEO-G474RE (2 boards)

• NUCLEO-H723ZG (1 board)

Each MCU board is interfaced with a TJA1050 CAN transceiver for CAN communication.

Hardware setup:

I am using STM32CubeIDE version 1.19.0 and have flashed the CAN firmware onto each board. An external CAN bus monitor/analyzer is connected to observe the CAN traffic.

I am able to successfully monitor CAN data from the two G474RE boards (the data is attached below), but I do not see any CAN messages from the H723ZG board on the bus monitor.

All boards are configured with the same CAN baud rate of 500 kbit/s.

CAN Identifiers Used:

• G474RE Board 1: 0x123

• G474RE Board 2: 0x124

• H723ZG Board: 0x125

Clock configuration:

G474RE (2 boards):-

SYSCLK: 170 MHz
FD CAN :170 MHz

H723ZG (1 board):-

SYSCLK: 550 MHz 
FD CAN : 137.5 MHz

Bus Monitor Data:

Pins details:

NUCLEO-G474RE:

PA12 - FDCAN1_TX 

PA11 - FDCAN1_RX

NUCLEO-H723ZG:

PD1 - FDCAN1_TX 

PD0 - FDCAN1_RX

How you establish the communication in the H723ZG board?

[mƎALLEm]

@Srivatsan and @Ben11 ,

I've merged the threads. Please continue the discussion here and please provide a status about what we have provided as answers previously.