2
\$\begingroup\$

On STM32F405 MCUs there are USART ports as well as UART ports available. If I need to implement RS-485 communication then which one of these should be used, USART or UART? Or are both of them equally good for RS-485 communication?

I have searched through the datasheet as well as reference manual for the MCU, but it does not provide additional information regarding the RS-485 implementation.

\$\endgroup\$
1
  • 2
    \$\begingroup\$ Why is this question tagged with "3.3v"? How is this relevant? \$\endgroup\$
    – Peter Mortensen
    Commented Feb 25, 2019 at 12:27

1 Answer 1

Reset to default
5
\$\begingroup\$

It doesn't matter as even if you're using a USART (which provides an additional CLK pin for synchronous operation) you'll only be using the UART part (RXD/TXD). Keep in mind that you'll need an additional pin for the Data Enable signal.

\$\endgroup\$
2
  • 2
    \$\begingroup\$ If you use full-duplex RS485, then you don't need a data enable signal. You only need one for half-duplex RS485 \$\endgroup\$
    – DKNguyen
    Commented Feb 25, 2019 at 5:36
  • 3
    \$\begingroup\$ @Toor For practical purposes, RS-485 without data enable signal would be RS-422. \$\endgroup\$
    – CL.
    Commented Feb 25, 2019 at 9:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.