Question
STM32H7B3I-EVAL RS-232 port not working while ST-LINK VCP works
I am using the STM32H7B3I-EVAL board. According to the user manual, both the ST-LINK Virtual COM Port and the RS-232 connector (CN9) use USART1 on PB14/PB15 in the default configuration.
I have configured USART1 in asynchronous mode with:
- TX: PB14
- RX: PB15
- Baud rate: 115200
- Hardware flow control: None
The ST-LINK VCP works correctly, and I can see the transmitted data on the PC. However, the RS-232 port on CN9 does not work.
I am using a DTECH USB-to-RS232 cable connected to CN9.
My questions are:
- Is any jumper or solder bridge configuration required to enable the RS-232 port, even when using PB14/PB15?
- Since both ST-LINK VCP and RS-232 share USART1, should the transmitted data appear on both interfaces simultaneously?
- Does CN9 require a straight-through RS-232 cable or a null-modem cable?
- Has anyone successfully used the RS-232 port on STM32H7B3I-EVAL with a USB-to-RS232 adapter?
Any suggestions on what else I should check would be appreciated.
