ESP8266 Community Forum

- Wed Sep 26, 2018 10:19 am #78400 Hi I am using NodeMCU ESP8266 ESP12E
My Arduino IDE is giving the following error
please help

Arduino: 1.8.7 (Windows Store 1.8.15.0) (Windows 10), Board: "NodeMCU 1.0 (ESP-12E Module), 80 MHz, Flash, 4M (1M SPIFFS), v2 Lower Memory, Disabled, None, Only Sketch, 115200"

Sketch uses 268560 bytes (25%) of program storage space. Maximum is 1044464 bytes.
Global variables use 30672 bytes (37%) of dynamic memory, leaving 51248 bytes for local variables. Maximum is 81920 bytes.
error: Failed to open COM3
error: espcomm_open failed
error: espcomm_upload_mem failed
error: espcomm_upload_mem failed

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

please tell me what am i doing wrong?

- Wed Sep 26, 2018 12:11 pm #78402 "Failed to open COM3" - you don't have COM3 or COM3 is already opened by another application.

- Thu Feb 21, 2019 1:33 am #80687 Hi,

Does Node mcu wifi module has any SDIO slave device in it? If yes how to access this SDIO device from an external SDIO host controller with an Arduino ide Code.

Thanks in Advance.