ESP8266 Community Forum

- Sun Nov 16, 2014 2:27 am #2705 You can reconfigure tx and rx pins as gpio

- Sun Nov 16, 2014 4:54 am #2707 ok, found and tested.
GPIO16 exists: it's XPD_DCDC and it works but it's not the RST pin which is just reset.
here they seem being connected

but it's not on my ESP-01.
also in driver folder of IOT example from official ESP SDK there is a gpio16.c, I tried that code and it works, but you can see it just probing the pin directly on the chip

- Sun Nov 16, 2014 5:20 pm #2766 I don't know where this schematic is coming from, but in all the ones I have seen until today, GPIO16 signal is connected to XPD_DCDC (pin 8 of ESP8266EX) only.

In your schematic, GPIO16 is indeed connected to XPD_DCDC (despite the overlapping "no connect" symbol), but not to EXT_RSTB, as there is an "NC" (no connect) resistor in between.

For the newer ESP-01 with 2 LEDs, the correspondence between module pins and ESP8266EX pins is (verified with a binocular):

Code: Select allModule | ESP8266EX
-------+----------
TX     | UTXD (pin 26, also connected to green LED)
GPIO2  | GPIO2 (pin 14)
CH_PD  | CHIP_EN (pin 7)
RESET  | EXT_RST (pin 32)
GPIO0  | GPIO0 (pin 15)
RX     | URXD (pin 25)

Conclusion: NO GPIO16 on ESP-01 module pins

- Thu Nov 20, 2014 11:40 am #2992 but which ones are they.. gpio?? and ??

You can reconfigure tx and rx pins as gpio

Peter Scargill - http://tech.scargill.net