UART hardware flow control

andrew_aus
Posts: 2
Joined: Fri May 24, 2019 8:42 am

UART hardware flow control

Postby andrew_aus » Fri May 24, 2019 9:04 am

Hi,

I plan on using the AT command firmware in an ESP32-WROOM-32D.

It appears to have hardware flow control (RTS/CTS) enabled by default.

I'm not using flow control and have left pins GPIO14 & 15 unconnected.

My question is what is the default state of the CTS pin (GPIO15) and what is the sense of CTS?

In other words I want to make sure that transmission out of the esp32 won't be blocked by default.

Helen L
Posts: 33
Joined: Thu Aug 16, 2018 9:07 am

Re: UART hardware flow control

Postby Helen L » Fri May 24, 2019 11:08 am

RTS CTS seems to be optional. Mine only connects TX, RX, GND and it works fine. No need to connect CTS and RTS. Maybe you can have a try.

andrew_aus
Posts: 2
Joined: Fri May 24, 2019 8:42 am

Re: UART hardware flow control

Postby andrew_aus » Fri May 24, 2019 11:30 pm

Thanks Helen, that's all I needed to know.
I couldn't try it because our custom board is yet to be manufactured and was checking if we should add any pull resistors on cts, but obviously not required.
Cheers.

Who is online

Users browsing this forum: Google [Bot], Zeni241 and 27 guests