3.8 KiB
Adafruit provides a really nice firmware flashing tutorial. Below you'll find just the basics for the two popular tools esptool and NodeMCU Flasher.
!!! note "Note:"
Keep in mind that the ESP8266 needs to be put into flash mode before you can flash a new firmware!
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.
If you have a NodeMCU dev kit then you don't need to do anything, as the USB connection can pull GPIO0 low by asserting DTR and reset your board by asserting RTS.
If you have an ESP-01 or other device without built-in USB, you will need to enable flashing yourself by pulling GPIO0 low or pressing a "flash" switch.
esptool
A cute Python utility to communicate with the ROM bootloader in Espressif ESP8266. It is intended to be a simple, platform independent, open source replacement for XTCOM.
Source: https://github.com/themadinventor/esptool
Supported platforms: OS X, Linux, Windows, anything that runs Python
Running esptool.py
Run the following command to flash an aggregated binary as is produced for example by the cloud build service or the Docker image.
esptool.py --port <USB-port-with-ESP8266> write_flash 0x00000 <nodemcu-firmware>.bin
NodeMCU Flasher
A firmware Flash tool for NodeMCU...We are working on next version and will use QT framework. It will be cross platform and open-source.
Source: https://github.com/nodemcu/nodemcu-flasher
Supported platforms: Windows
Upgrading from SDK 0.9.x Firmware
If you flash a recent NodeMCU firmware for the first time, it's advisable that you get all accompanying files right. A typical case that often fails is when a module is upgraded from a 0.9.x firmware to the latest version built from the NodeMCU build service. It might look like the brand new firmware is broken, but the reason for the missing Lua prompt is related to the big jump in SDK versions: Vendor Espressif changed the esp_init_data_default.bin for their devices along the way with the SDK 1.4.0 release. So things break when a NodeMCU firmware with SDK 1.4.0 or above is flashed to a module which contains old init data from a previous SDK.
Download a recent SDK release, e.g. esp_iot_sdk_v1.4.0_15_09_18.zip or later and extract esp_init_data_default.bin from there. Use this file together with the new firmware during flashing.
esptool
For esptool you specify another file to download at the command line.
esptool.py write_flash 0x00000 <nodemcu-firmware>.bin 0x7c000 esp_init_data_default.bin
!!! note "Note:"
The address for `esp_init_data_default.bin` depends on the size of your module's flash. ESP-01, -03, -07 etc. with 512 kByte flash require `0x7c000`. Init data goes to `0x3fc000` on an ESP-12E with 4 MByte flash.
NodeMCU Flasher
The NodeMCU Flasher will download init data using a special path:
INTERNAL://DEFAULT
Replace the provided (old) esp_init_data_default.bin with the one extracted above and use the flasher like you're used to.