ESP8266 Community Forum

- Sun May 17, 2015 4:13 am #17624 So, I am stuck with my Olimex ESP8266-DEV Board (https://olimex.wordpress.com/tag/esp8266/ the module with the breakout board).

As I am on MacOS X, I had to hack Arduino 1.6.1 IDE to work with pyesptool instead of the built-in esptool. GPI02 is connected to +3.3V by default.

This is what I have attempted:

- With GPIO0 to GND (so called UART mode, check: https://goo.gl/238T0F ).

I managed to flash the board only once, and this has been pretty much it.

I get the following error when trying to reprogram the board:

Code: Select allConnecting...
Traceback (most recent call last):
  File "./esptool.py", line 479, in <module>
    esp.connect()
  File "./esptool.py", line 157, in connect
    raise Exception('Failed to connect')
Exception: Failed to connect

I get the green light flashing on the board - so I am guessing that something is happening.

I have also tried on a PC, without much luck.

- With GPIO0 to +3.3V (High):

The Blink program runs fine.

I am unable to connect via a serial connection in either mode, I have used 'screen' and 'CoolTerm'. I am not even getting garbage printed.

I sense that I probably wipe the board clean of any firmware other than the blink code, and that I am unable to trigger a serial connection on the board.

Any hints?

TIA

- Sun May 17, 2015 4:17 am #17625 Did you also pull gpio2 and gpio15 to ground?

- Sun May 17, 2015 4:35 am #17627 The board schematics indicates that both GPIO2 and GPIO15 are connected with a resistor (2.2k and 47k, respectively) to +3.3V.
(https://goo.gl/NFMJ7b )

Leaving GPIO2 floating does not help either.

I have just tried taking both GPIO2 and GPIO0 to GND, no luck.

Last edited by tareumlaneuchie on Sun May 17, 2015 4:45 am, edited 1 time in total.

- Sun May 17, 2015 4:38 am #17628 When flashing they still need to be pulled down (at least gpio15, iirc).