Unbrick Esp8266 Blinking led blue

This post is outdated better to go here and ready, with esptool, you can do all this.

Many times this will happen to us, and if not it will happen someday, it is because of the incomplete firmware in the esp8266, affecting the communication with the bootloader.

Esp8266 Flash Downloader

This application will flash the original firmware with AT commands, which we will later remove with nodemcu, not change the memory address (0x00000).

Esp8266 flash downloader.

v0.9.2.2 AT Firmware.bin.

We start by removing voltage on vcc from 3.3v connect and immediately press Download

  • Pin GPIO0 to ground press Download button (Programming mode)
  • The RST button on the arduino to ground, release (can be adjusted with a button) and press the Download button, the console output should be as follows

Then disconnect GPIO0 from ground to not enter flash mode.

Esplorerv0.2.0-rc6 IDE with an environment to program the ESP8266, NODEMCU etc…internal code without affection.


This application allows to flash also with other functionalities from micropython, lua, at, etc. We will use it to see the output in console, if the system has been flashed correctly, it could also serve the Arduino ide.

This version is giving a failure to open with the jssc that loads by default, problems with the .dll of each OS.

Here we will connect to the esp8266 by the serial port through the arduino.

  • Choose arduino com port
  • Baute rate: 9600
  • Click on open
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[System Ready, Vendor:www.ai-thinker.com]

Again withNodemcu firmware programmer

We return to the NODEMCU with GPIO0 set to GND (programmer mode), to forget about AT commands.


Here is the output on successful unbriking.


Communication with MCU..Got answer! Communication with MCU established.
AutoDetect firmware...

NodeMCU firmware detected.