Well, it's a bit embarrassing, but I found the issue. I'm sorry for not having thought of that before.
The issue was that the `echo` command I was doing were enough information for my logic analyzer to pick up. If I tried the `serialblaster` I was able to see data on the line. I've confirmed it worked with the `echo` command, just that I needed a longer string. I was not expecting this to be an issue. Sorry again everybody for the disturbance, and thank you for your understanding. Ludovic Vanasse *Embedded Software Developper* 1 514 475-0447 On Tue, Aug 12, 2025 at 2:33 PM Ludovic Vanasse <lvana...@luxaerobot.com> wrote: > Hi everybody, > > I'm working on porting NuttX to the Nucelo-H753ZI and basing it on the > Nucelo-H743ZI. It's going pretty well. > > But now I feel like I've hit a wall, and I am coming here to see if > anybody has an idea as to what might be the issue. > > I'm planning to use NuttX for High Altitude balloons, and I'm preparing > the groundwork for the rest of my team to then split the work between us. > Which involve interacting with SATCOM modules, GPS, radios, etc. > > And I'm trying to do something very basic, but I'm having issues. I want > to be able to validate that the UART6 is working well, so I can validate > that the porting is working for this peripheral. And I'm trying to simply > send some data down the line with nsh. With this command: > > ``` > nsh> echo "test" > /dev/ttyS1 > ``` > > But I'm not seeing anything on my Saleae logic analyzer. > > Here's the configuration I'm using for the UART on the Nucleo-H753ZI: > > ``` > CONFIG_STM32H7_USART3=y > CONFIG_STM32H7_USART6=y > > CONFIG_ARCH_HAVE_SERIAL_TERMIOS=y > CONFIG_SERIAL=y > CONFIG_SERIAL_CONSOLE=y > CONFIG_MCU_SERIAL=y > CONFIG_STANDARD_SERIAL=y > CONFIG_SERIAL_NPOLLWAITERS=4 > CONFIG_USART3_SERIAL_CONSOLE=y > CONFIG_USART3_SERIALDRIVER=y > CONFIG_USART6_SERIALDRIVER=y > > CONFIG_USART6_RXBUFSIZE=252 > CONFIG_USART6_TXBUFSIZE=252 > CONFIG_USART6_BAUD=115200 > CONFIG_USART6_BITS=8 > CONFIG_USART6_PARITY=0 > CONFIG_USART6_2STOP=0 > ``` > > In my board.h I have this configured for the UART6: > > ``` > /* USART6*/ > #define GPIO_USART6_TX (GPIO_USART6_TX_1 | GPIO_SPEED_100MHz) /* PC6 AF7 > */ > #define GPIO_USART6_RX (GPIO_USART6_RX_1 | GPIO_SPEED_100MHz) /* PC7 AF7 > */ > ``` > Which is based on this config: > https://os.mbed.com/platforms/ST-Nucleo-H743ZI/, I've also confirmed this > in ST user manual and datasheets. And it's similar to the initialization of > that UART in the linum-stm32h753zi: > https://github.com/apache/nuttx/blob/master/boards/arm/stm32h7/linum-stm32h753bi/include/board.h#L379 > > And of course I've configured my Saleae logic analyzer to use 115200 > baudrate, 8bit, no parity bit. > > [image: image.png] > > > And here's the NSH where I try to send data down the UART6: > [image: image.png] > > But nothing happens on my Saleae. > > I'm at the point of going through GDB and checking if there's indeed data > being written down the register, but I thought I'd ask the community for > guidance in resolving this issue in parallel. > > Thanks in advance! > > Best regards, > > Ludovic Vanasse > > > *Embedded Software Developper* > > 1 514 475-0447 >
