__flashing esp8266

source

To enable ESP8266 firmware flashing GPIO0 pin must be pulled low before the device is reset. Conversely, for a normal boot, GPIO0 must be pulled high or floating.

source

connect gpio00 to gnd

and after click button firmware flash put reset to gnd and look to us adapter for blink rx and tx led in same time for low time and need after second to begin upload (the rx and tx led blinking with speed)

if not succeed ... repeat rst to gnd !

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flash directly

esptool.exe -vv -cd nodemcu -cb 115200 -cp COM3 -ca 0x00000 -cf reset.bin