USART VCP connections on NUCLEO-L432KC

[Sebastian K.]

Posted on January 02, 2018 at 16:32

Hello,

I just bought a NUCLEO-L432KC board. I understand that of its 2 USARTs the USART2 is connected to the ST-Link Virtual Com Port via pins PA2 and PA15.

The RX pin PA15 apparently is not broken out on the Nucleo board, so I cannot use it to connect another device. But in CubeMX I have the possibility to define PA3 as an alternate USART2_RX pin, which is accessible on the board.

If I wanted to use both USARTs to connect devices that send data to the L432, can I re-route the pins like that without breaking the capability to program the chip from the PC? I guess that PA15 is still physically connected to the VCP via the solder bridge, but can it still be used then to erase/re-program the chip? Or will I brick my board once I upload a software with that pin assignment?

Thanks.

#virtual-com-port #nucleo-l432kc

[Ben K · Accepted solution]

Posted on January 03, 2018 at 09:46

The device is programmed via ST-Link interface, which uses SWCLK and SWDIO (PA13 and PA14), the VCP can be used to transfer data between the application on the MCU and the PC. Therefore there is no limitation in using the USART2 on different pins.

[Sebastian K.]

Posted on January 03, 2018 at 11:09

Great, thanks for the clarification!