ESP8266 Community Forum

- Mon Mar 06, 2017 10:52 am #63418 Hi,

I am using ESP-WROOM-02 WiFi module and have created some projects using that. We have one requirement to use UART0 Debug UART with Hardware Flow Control Support (RTS and CTS).

We have configured UART0 properly as per RTS and CTS Pin configurations required and connected with Debug Serial UART with RTS and CTS pins in swap.

Following are UART0 ESP8266 Pin configurations with our Serial Debug Cable

ESP8266 :: Serial UART
RX :: TX
TX :: RX
RTS :: CTS
CTS :: RTS
GND :: GND

So, when i tried to connect RTS Pin of ESP8266 with CTS Pin of Serial UART Cable at that time only single way means ESP8266 can only send data to Serial UART only.

Please let me know if any one has proved communication of UART0 with RTS/CTS Pins or let me know any clue for this type of issue which we are facing.

- Tue Mar 07, 2017 11:29 pm #63456 Hi,

Anyone has any update regarding this issue?

Also we have checked UART0 with RTS+CTS Hardware Flow control into ESP8266 AT NonOS 0.51 firmware in which i am able to configured UART with RTS+CTS configuration and it is working fine without any issue.

SO, It seems like that Hardware is proper to support UART0 RTS+CTS support. So, I will verify UART driver of ESP8266 RTOS SDK and will also verify application level code for that.

Let me know if anyone has worked on UART0 with Hardware Flow control (RTS+CTS) into ESP8266 RTOS SDK.

- Thu Mar 09, 2017 5:14 am #63492 Hi,

Anyone has any update regarding this issue?

- Thu Nov 09, 2017 9:48 am #71687 I have already been using wroom-02 without hw uart flow control without any issue. Now I am starting a new project in which I plan to use RTS/CTS. What I have found out so far is that regardless of RTS/CTS UART settings ( commands AT+UART_DEF or _CUR), at reset, both pins (RTS and CTS) should be pulled low in order to get "ready" at the end of boot up gibberish. After that both pins seem to gain normal functions as RTS/CTS. This is just a conclusion after short experimenting, but it should be a good starting point.