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Getting UART to RTS to work when using ESP8266 Arduino

PostPosted: Mon Jan 18, 2016 3:02 am
by mountaindude
So, I am trying to connect the ESP8266 to a half-duplex uart-to-RS485 (https://www.sparkfun.com/products/10124) board, and then read data from an energy meter over RS-485.

The challenge is that the uart-to-RS485 board is half duplex, and requires a RTS signal to enable the rx or tx through the chip.
RX and TX for the default UART (which is... uart0?) works great, but I cannot get RTS to work.. From what I understand it should be available on the MTDO/GPIO15 pin - but no luck there. That pin just stays the same, no matter how much I send to or read from the uart on the rx/tx pins.

Do I have to specify somehow that MTDO/GPIO15 should be used for RTS?
If so, how is that done?ยจ

Thanks!

Re: Getting UART to RTS to work when using ESP8266 Arduino

PostPosted: Tue Mar 01, 2016 8:02 pm
by JimDrew
BUMP! I have the same issue. Does anyone know how to enable the RTS with UART0? I am using a transparent serial bridge and when transferring a large file at 9600 baud (the host requirement) I get mass amount of errors because the entire file is basically sent instantly!

Re: Getting UART to RTS to work when using ESP8266 Arduino

PostPosted: Tue Mar 01, 2016 8:14 pm
by martinayotte
Did you tried to switch GPIO pin mode function using pinMode(pin, FUNCTION_4) ?
wiki/doku.php?id=esp8266_gpio_pin_allocations