ESP8266 Community Forum

- Mon Mar 13, 2017 7:16 am #63637 Hi!
So to begin with I'll explain how everything is connected.
ESP-12E is connected to external power supply (~3.3V)
I use Arduino UNO (powered by USB) as FTDI.
GND ----> GND (3.3V)
VCC ----> 3.3V
CH_PD ----> 3.3V
GPIO15 ----> GND (3.3V)
GPIO2 ----> 3.3V
GPIO0 ----> GND(3.3V)
RXD ----> Logic level converter ----> Arduino RX
TXD ----> Logic level converter ----> Arduino TX

I use Arduino ide 1.6.13 with ESP8266 library to upload code.
In Arduino ide - Board: Generic Esp8266 Module(tried also second Generic ESP8266 and Node MCU 1.0(ESP-12E) )

So the problem is that some time ago I managed to upload something to my esp (and it didn't work ) , but since then I am unable to upload anything and use AT commands. Every time I upload sketch I get this error:

warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed

I don't know whether I'm doing constantly a silly mistake or maybe my esp is just damaged. Also I've searched a lot of forums and run through a lot of websites and none of them seemed to help me.

PS I am not native so sorry for any mistakes in English, I do my best

- Fri Mar 17, 2017 10:39 pm #63873 I got a 12 about a week ago. The only thing I am seeing different from what i do, is I leave GPIO2 unconnected, but maybe that is why I sometimes have trouble. I've had about a 40% success rate in uploading. I always disconnect / reconnect power and reset before uploading. Sometimes it helps to switch to 9600 baud.

V+ to either regulated 3.3 or 5v
GND to GND
CH_PD = 3.3
GPIO0 = GND
GPIO15 = GND
RX to RX
TX to TX
ESP GND to Arduino GND

- Sun Mar 19, 2017 4:30 am #63926 Having uploaded a sketch, you will no longer be able to use AT commands, because your sketch has replaced the AT command interpreter; so don't worry about that.

Are you sharing the GND line between the external supply, ESP and Arduino?

- Thu Apr 06, 2017 10:22 am #64684 I'm very new, but isn't Rx of ESP8266 supposed to go to Tx on FTDI/Uno and vice versa?