UART message on STM32 IoT node doesn't show up on virtual terminal.

[ambinabhi]

I am playing around with the STM32 IoT node discovery kit, came across this strange behavior while using USART. When only LED_2 and UART are enabled on CubeMX (using SMT32CubeIDE btw) and simple blink(toggle) and a USART message is sent and it doesn't show up on terminal (TeraTerm) although the toggle works fine according to delay set. However on the debugger i can see UART_Transmit function working fine and returns HAL_OK. I am not sure why the message doesn't show up on terminal.

But when i enable all default pin and configurations the message does seem to appear on terminal.

Any idea/help is much appreciated. Attached the sample code below.

[S.Ma]

When HAL_OK returns from sending bytes it's like the brain sent message to a limb (GPIO) even if it is missing. Check for the GPIO pin configuration and especially alternate functions and GPIO port clock enable. A scope on USART pin could help root out the lurking bug.

[Tesla DeLorean]

https://www.st.com/content/ccc/resource/technical/document/user_manual/group0/b1/b8/7a/f2/f7/8d/4b/6b/DM00347848/files/DM00347848.pdf/jcr:content/translations/en.DM00347848.pdf

Using the WRONG pins for USART, using PA9/PA10, when the board used PB6/PB7

[ambinabhi]

Yea, that's strange cause i am generating it from CubeMX, when i enable USART1 from connectivity section it selects PA9 and PA10. But when i manually do assign PB6 and PB7 the project doesn't compile since USART1 is not enabled.

[Tesla DeLorean]

I'm not using CubeMX, could be driver error, but you can just edit the code in the stm32l4xx_hal_msp.c file to change the pins