The pre-compiled binary files can be found here on the GitHub Releases Page (the right column on the projects start page). Currently there are pre-compiled binaries for ESP32 and ESP32-S3 MCUs. Pre-compiled binaries for other controllers like the ESP32-C2 etc. may follow in future.

Overview of pre-compiled binaries

All pre-compiled binaries require a mandatory Device Profile. You have to upload one after flashing the firmware!

Binary	MCU	Device Profile mandatory	First Flash / OTA	Comment
opendtu-generic.bin	ESP32	No	OTA	Deprecated!
opendtu-generic.factory.bin	ESP32	No	First Flash	Deprecated!
opendtu-generic_esp32.bin	ESP32	Yes	OTA
opendtu-generic_esp32.factory.bin	ESP32	Yes	First Flash
opendtu-generic_esp32s3.bin	ESP32-S3	Yes	OTA	For boards with usb-uart bridge
opendtu-generic_esp32s3.factory.bin	ESP32-S3	Yes	First Flash	For boards with usb-uart bridge
opendtu-generic_esp32s3_usb.bin	ESP32-S3	Yes	OTA	For boards with integrated usb connection
opendtu-generic_esp32s3_usb.factory.bin	ESP32-S3	Yes	First Flash	For boards with integrated usb connection

Initial flash procedure

Flash all in one .factory.bin file

For a first installation, download opendtu-generic*.factory.bin (depending on your MCU) and use a ESP32 flash tool of your choice to flash the .bin file to the address 0x0.

Available Flash Tools

Flash with esptool.py (Linux)

Replace the port /dev/ttyUSB0 for your needs.

esptool.py --port /dev/ttyUSB0 --chip esp32 --before default_reset --after hard_reset \
  write_flash --flash_mode dout --flash_freq 40m --flash_size detect \
  0x0 opendtu-generic*.factory.bin

Flash with Espressif Flash Download Tool (Windows)

Download link

• On startup, select Chip Type -> "ESP32" / WorkMode -> "Develop"
• Prepare all settings (see picture). Make sure to uncheck the DoNotChgBin option. Otherwise you may get errors like "invalid header".
• 
• Press "Erase" button on screen. Look into the terminal window, you should see dots appear. On some boards, the automatic bootloader selection does not work. In this case you have to manually press the "Boot" button on the ESP32 board. Wait for "FINISH" to see if flashing/erasing is done.
• To program, press "Start" on screen, then the "Boot" button (if required).
• When flashing is complete (FINISH appears) then press the Reset button on the ESP32 board (or powercycle ) to start the OpenDTU application.

Flash with ESP_Flasher (Windows)

Users report that ESP_Flasher is suitable for flashing OpenDTU on Windows.

Flash with ESP_Flasher - web version

It is also possible to flash it via the web tools which might be more convenient and is platform independent.