STM32H747I-EVAL Uart Receiving issue

[Shiv09]

Hello All,

I am working on STM32H747I-EVAL for one of the application development where I am using the uart for communication. I am using UART2 with below pins for my commands and response communication with interrupt mode on 115200 baudrate.

    PA2   as USART2_TX

    PA3  as USART2_RX

I am able to send and receive proper command and response using the Docklight can see the communication happening between Docklight and STM32H747I-EVAL  using CM7 on USART2. 

When I am trying the same with other STM controller to send and receive the same packets, I am not able to receive the packet from other STM controller, though I am able to see the USART2_TX working(Command send from STM32H747I-EVAL to other STM and it is responding back with some data), now here I am not able to receive the Data (which works with Docklight). 

Could you please suggest why or how to get this fix ? Any suggestions or tries to make it, will try as suggested.

Regards,

SMD

[Andrew Neil]

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@Shiv09 wrote:

When I am trying the same with other STM controller to send and receive the same packets, I am not able to receive the packet from other STM controller

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Does that "other STM controller" receive anything from your STM32H747I-EVAL?

Have you tested that "other STM controller" against Docklight?

Are you sure that "other STM controller" is using the correct baud rate, voltage levels, etc?

Is there a good ground connection between the two?

Have you monitored the connections between your two controllers to see what's actually happening on the wires?

Tips on Debugging Serial Comms.

[Shiv09]

Hello @Andrew Neil ,

Thanks for the quick reply, here are the observations 

Does that "other STM controller" receive anything from your STM32H747I-EVAL? 

Yes, it is receiving the data packet.

Have you tested that "other STM controller" against Docklight?

Yes, it is able to send packet on docklight.

Are you sure that "other STM controller" is using the correct baud rate, voltage levels, etc?

Both have made on 115200 baud rate, for voltage levels need to check.

Is there a good ground connection between the two?

Yes.

Have you monitored the connections between your two controllers to see what's actually happening on the wires?

On both the controller TX connected to RX and vice versa, only STM32H747I-EVAL is able to send Data to other STM device, and it is receiving the command properly, now when other STM device is sending the data, I can receive data on STM32H747I-EVAL. this is something strange not sure why this is happening. 

[Andrew Neil]

But have you monitored the connections between your two controllers to see what's actually happening on the wires?

eg, using an oscilloscope, analyser, or just a separate serial port?

Note that describing electronic circuits and connections in words is a very poor way to communicate - a diagram would be much clearer ...

[Shiv09]

Hello @Andrew Neil ,

Got some troubles with other STM board its completely dead now, so not able to see exactly the waveforms, will update you soon as we make the other board ready. Just give me few days to get on track.

Yes, agreed it's difficult to explain in words about the issue, will share the images once we get both the boards ready.

Thanks for the co-operation.