The image_user* files were built in the Arduino IDE using this file: https://github.com/sillyfrog/Espressif2Arduino/tree/master/Espressif2Arduino
These have been built to use a flash mode of DOUT, which appears to be most compatible with newer Sonoff devices.
The options used for the build (after doing the setup as per https://github.com/khcnz/Espressif2Arduino) were:
- Set flash mode to anything (.elf files don't use this)
- Board: Generic ESP8266 Module
- Flash Size: "1M (Espressif OTA Rom 1)"
Then I ran the following to get Espressif2Arduino.ino-0x01000.bin:
esptool.py elf2image --flash_mode=dout --version 2 Espressif2Arduino.ino.elf
I then did a build again in Arduino with the option:
- Flash Size: "1M (Espressif OTA Rom 2)”
And finally to get Espressif2Arduino.ino-0x81000.bin:
esptool.py elf2image --flash_mode=dout --version 2 Espressif2Arduino.ino.elf