stm32f722ZE Nucleo UART sample code problem

[David Pekin]

Posted on January 10, 2018 at 21:56

Hello, 

I've just built the UART sample code for the 722ze Nucleo board and have a problem. I have not modified the code (except for the transmitted character buffer).  The sample code shows setting up the unit for a 9600 N81 format.  The character buffer that is transmitted is 153 characters long.  When I transmit from the Nucleo I receive the correct number of characters on the RealTerm serial capture program but it's gibberish.  None of the ASCII characters are discernable and I can't make heads or tails of how the bits might be shifted...  For example, I am sending '12345' which in hex is 0x31 0x32 0x33 0x34 0x35  and I receive 0xEB 0x9B 0x99 0x97 0x95.  

Has anyone seen anything like this? 

[Tesla DeLorean]

>>I understand

Not sure you do, you seem confused.

The NUCLEO-H743ZI has a USART connected to the VCP provide by the ST-LINK, you can send data to the USART on the H7 side and get the data on a PC side terminal application.

You can also connect a SiLabs CP2102 type USB-to-CMOS Serial dongle to any of the other available USART on the board.

You can also use the Serial Wire Viewer (SWV SWO/PB3) as a debug terminal.

[ranran]

Hi Clive,

You right. I just got a board today, so I am a bit too much enthusiastic..

I managed to see printf using the SWV.

But I don't understand the 1st option you've mentioned:

"The NUCLEO-H743ZI has a USART connected to the VCP provide by the ST-LINK"

How do I use this UART, which UART number is it ? Is there an example showing how to use it (actually I tried all examples).

Thanks!

ran

[Tesla DeLorean]

The User Manual and Schematic indicate it is USART3 on PD8/PD9

[ranran]

Right, I wonder why there was no example using this USART3...

I shall try it. Thanks !

[ranran]

It does work with USART3, just what I needed ! Thanks a lot