ESP8266 Community Forum

- Sun Feb 05, 2017 6:47 pm #62110 Hi,

I am a complete n00b to NodeMCU so please bear with me.

I recently received a new HiLetgo NodeMCU dev board and attempting an initial connection over USB (board placed on a blank breadboard and connected to the mini-USB cable).

I first connected the board to my PC's USB port. Windows detected the CP2102, auto-installed the Silicon Labs USB to UART Bridge driver, and presented a COM port.
I then opened Arduino IDE, set it up for esb8266/NodeMCU 1.0, selected the new COM port and attempted to upload the blink example. The result was:

Code: Select allwarning: espcomm_sync failed
error: espcomm_open failed

I tried different baud rates, USB ports, mini-USB cables, another Windows PC, but result is always the same. Serial Monitor is also blank and no commands are accepted.

I then set up my Mac with the ESPtool and installed the driver, connected the NodeMCU (/dev/cu.SLAB_USBtoUART is available), and attempted:

Code: Select all$ esptool.py -b 9600 --port /dev/cu.SLAB_USBtoUART flash_id

output is:

Code: Select allesptool.py v1.3
Connecting...................

A fatal error occurred: Failed to connect to ESP8266: Timed out waiting for packet header

So my guess is that while the UART is functioning, the ESP module is not responding.

Also when I hook up the module to USB, device is detected by Windows and LED behavior is in one of two states:

1. No LEDs are ever on or blink
2. A very faint red LED is lit (next to the voltage regulator)

Not sure what else to try at this point. Is it possible I am dealing with a DoD board?

Thank you

- Tue Feb 14, 2017 2:05 am #62541 I am saying a very obvious thing but are you putting your nodeMCU into flash mode before you try to upload to it? To put in flash mode: Reset the board while holding down the flash button i.e. hold down the flash button -> press reset button -> leave the flash button.
If your ESP8266's blue LED flicks on powering up, your board is most probably fine. One of your RESET or FLASH buttons may be dud, my reset button is like that. So what you can try is use the RESET and D3 (alias GPIO0) to trigger boot mode. Do so: Ground D3 by connecting to GND -> Reset the board by grounding RST for a moment or simply power up with D3 grounded -> You should be in the boot mode -- Don't forget to remove chip from boot mode by "ungrounding" D3 if you manage to flash the chip successfully.

Beware! I know less than I give away.