Hi,
Reference: AN5179 - RS232 communications with a terminal using the STM8 Nucleo-64 boards
https://www.st.com/resource/en/application_note/dm00513075-rs232-communications-with-a-terminal-using-the-stm8-nucleo64-boards-stmicroelectronics.pdf
AN5179 page 6 have a circuit of RS232 communication with a terminal using NUCLEO-8L152R8 board and I want to know if the same circuit can be used with STM8L-DISCOVERY changing only USART port.
I have two questions:
1. In STM8L152R8 datasheet we can see that almost all ports including USART default port and PB5 are FT (5V tolerant). But in STM8L152C6 datasheet we can see that almost all ports including USART port and PB5 are TT (3.6V tolerant). Is this a mistake in STM8L152C6 datasheet or those ports are only 3.6V tolerant?
2. In case STM8L152C6 ports are only 3.6V tolerant, can I connect STM8L152C6 USART TX and RX pins directly to ST232B RS232 driver and PB5 configured as output type open-drain, with a LED and a resistor to 5V? (I believe that when LED is off or input is floating as after reset, PB5 voltage is near 5V, so exceeds 3.6v. Also ST232B output is 0V or 5V)
