2022-01-27 01:37 AM
I've been trying to get the Virtual COM port from the ST-LINK on a NUCLEO-L4A6ZG working for 2 days now without luck. I've had no problem configuring the UART3 on a NUCLEO-F429ZI to work with the Virtual COM port. Only thing different is that the former is on the LPUART and the later is on the usual USART/UART. I've accounted for the different Baud Rate Register factor. How does the UART on the F103 of the ST-LINK detect the speed of the UART from the main board? Is it the UART on the ST-LINK restricted to a particular set of parameters? I've tried 115200,N81 and numerous other baud rates from 2400 and up without luck.
On the same NUCLEO-L4A6ZG I am able to configure the UART2 for successful communication to another board but the solution for the LPUART1 on this board eludes me.
I don't think I'm doing anything special with the LPUART1 on this board. In fact the NUCLEO-WL55JC1 I have also uses LPUART1 connected to the virtual com port and I have that working without issues.
How does the ST-LINK's F103 UART detect what baud, word length, stop bits, and parity is being used by the main board?
2022-01-27 01:56 AM
Hello,
LPUART1 is on GPIOG Pins 7 and 8, and without seeing your code, I would say you don't activate GPIOG pins that are relying on VDDOI2 power.
Please call HAL_PWREx_EnableVddIO2(); function.
2022-01-27 10:05 AM
Thanks! That was it! I totally overlooked the PWR control component. I assumed my predecessor took care of such things on this when bringing up this MCU and I didn't find any bread crumb reminders in UM2179 nor RM0351 when reading the GPIO and LPUART portions that this needed to be done.