You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@nuttx.apache.org by "maxikrie (via GitHub)" <gi...@apache.org> on 2024/03/09 02:21:35 UTC
[I] STM32: UART write issue [nuttx]
maxikrie opened a new issue, #11877:
URL: https://github.com/apache/nuttx/issues/11877
Hello,
I am trying to write to a UART port on the nucleo-h743zi2 development board (also the stm32f4discovery development board), unfortunately with no success. However on the ESP32S3-devkit it works.
The code is the following, where "/dev/ttyS1" is the UART device (I tried USART2 on TX pin PD5 and UART5 on TX pin PC12).
```
int fd = open("/dev/ttyS1", O_RDWR | O_NOCTTY | O_NONBLOCK);
if (fd < 0)
{
printf("open failed: %d\n", errno);
return 1;
}
int ret = write(fd, "Hello, World!!\n", 16);
if (ret < 0)
{
printf("write failed: %d\n", errno);
return 1;
}
printf("write returned: %d\n", ret);
close(fd);
```
The code returns that 16 bytes were written successfully, but I don't receive anything on my PC (connected with a USB-to-serial cable). If I run the same code on a ESP32 (UART1 on TX pin 17) I see the expected output in the console.
I have also tried the other way around, sending data from the console to the boards and receiving data with the serialrx example. This works for either nucleo-h743zi2 and ESP32S3-devkit.
When I check the wires with a logic analyzer, I see that that the TX line is normally 0 on the STM32 while it is normally 1 on the ESP32. When I execute the code, the line goes briefly goes to 1 (but doesn't contain any information). On the ESP32 I see the expected information ("Hello, World!!\n") on the line.
Thanks for any hints!
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: commits-unsubscribe@nuttx.apache.org.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
Re: [I] STM32H7 (& STM32F4): UART write issue [nuttx]
Posted by "acassis (via GitHub)" <gi...@apache.org>.
acassis commented on issue #11877:
URL: https://github.com/apache/nuttx/issues/11877#issuecomment-1988306785
@maxikrie I think these differences between ESP32 and STM32 could happen because the former has internal HW FIFO and the later doesn't.
More info about O_NONBLOCK please read the man pages:
$ man 2 open
$ man 2 fcntl
Also I found this page with useful information about it: https://wiki.sei.cmu.edu/confluence/display/c/FIO32-C.+Do+not+perform+operations+on+devices+that+are+only+appropriate+for+files
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: commits-unsubscribe@nuttx.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
Re: [I] STM32H7 (& STM32F4): UART write issue [nuttx]
Posted by "maxikrie (via GitHub)" <gi...@apache.org>.
maxikrie closed issue #11877: STM32H7 (& STM32F4): UART write issue
URL: https://github.com/apache/nuttx/issues/11877
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: commits-unsubscribe@nuttx.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
Re: [I] STM32H7 (& STM32F4): UART write issue [nuttx]
Posted by "maxikrie (via GitHub)" <gi...@apache.org>.
maxikrie commented on issue #11877:
URL: https://github.com/apache/nuttx/issues/11877#issuecomment-1988330586
@acassis Thanks a lot!
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: commits-unsubscribe@nuttx.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
Re: [I] STM32H7 (& STM32F4): UART write issue [nuttx]
Posted by "acassis (via GitHub)" <gi...@apache.org>.
acassis commented on issue #11877:
URL: https://github.com/apache/nuttx/issues/11877#issuecomment-1986987674
@maxikrie I used zmodem running on STM32F4Discovery and it worked, so the TX/RX is working. BTW, are you using DMA? Could be related to same issue they are discussing in the mailing list.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: commits-unsubscribe@nuttx.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
Re: [I] STM32H7 (& STM32F4): UART write issue [nuttx]
Posted by "maxikrie (via GitHub)" <gi...@apache.org>.
maxikrie commented on issue #11877:
URL: https://github.com/apache/nuttx/issues/11877#issuecomment-1987368423
@acassis Thanks for the hint! It lead me to the solution.
The issue in my example was the `O_NONBLOCK` flag. I guess immediate `close(fd);` causes the bytes not to be written in this case? I was mislead by the fact that `write` would return the correct amount of bytes written. Also, this example was working on the ESP32, which confused me.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: commits-unsubscribe@nuttx.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org