The actual flashing of firmware files such as .bin files or “binarys” on the Wemos D1 Mini, the NodeMcu dev board or any other board that is based on the ESP8266 takes place completely in the background of the Arduino IDE.
Behind it is actually the “esptool” offered by Espressif – the manufacturer of the ESP8266. With the right parameters, you can easily transfer finished .bin files to the ESP8266 without having to rely on the Arduino IDE.
A simple and a slightly more challenging how to do that is described in this article.
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You can always find the current version of the addressed “esptool” in the manufacturer’s git at:
“Problem” is that this tool is a Python script / application and therefore cannot be run directly / easily under Windows.
Conveniently, Python scripts can also be “packed” into a compact .exe file. This also makes handling under Windows easier.
How to do this is described in the article Python – Pack Esptool.py into Esptool.exe.
Alternatively, you can also use the (somewhat older) prepared releases at
For the rest of this article you don’t have to organize the esptool yourself but you can also simply use the esptool.exe file in the following git.
Transfer an existing .bin file with the esptool and the ESPEasy Flasher
If you only want to “armed” with the esptool to transfer a .bin file to the ESP8266, this usually means that you have to call the esptool from the command line and with the appropriate parameters.
This is often difficult for less advanced users and, apart from that, it is simply impractical.
Others have already noticed this and therefore worked on how to make the flash process of the ESP8266 as simple as possible.
You can find one of these results in the following git at
as always there is a backup on the Nerdiy-Git:
In addition to the esptool.exe mentioned in this git, there is also a FlashESP8266.exe. The latter functions like a graphical user interface, which translates the inputs made with the mouse into parameters and a command line call. Exactly what that means is explained in the next paragraph. The easy way starts right here. 🙂
Now all you have to do is click on the “Flash” button and the selected binary will be transferred to your ESP.
Another important note: The list of available COM ports is only updated when the application is restarted. If you have connected your ESP when the program was already started, you have to close it and open it again.
Call Esptool from the command line
As mentioned, you can also use the esptool directly to transfer an existing binary to your ESP.
To do this, you must use the command line to call the esptool with the specified parameters as follows:
esptool.exe -vv -cd nodemcu -cb 921600 -cp COM32 -ca 0x00000 -cf C:ESPEasy.ino.bin
- The number “921600” corresponds to the baud rate with which your ESP is programmed. This can vary from model to model. Typical baud rates are “9600”, “115200” or “921600”. If one baud rate doesn’t work, you can simply try another one.
- The “COM32” part corresponds to the COM port under which your connected ESP can be reached.
- “0x00000” corresponds to the memory area from which the binary should be written to the ESP memory. Usually you shouldn’t change this value.
- The part “C: ESPEasy.ino.bin” is important now. The path to your binary must be specified here. If you have copied your binary to your C: drive and called it “ESPEasy.ino.bin”, this value can remain the same.
Have fun with the project
I hope everything worked as described. If not or you have any other questions or suggestions, please let me know in the comments. Also, ideas for new projects are always welcome. 🙂
P.S. Many of these projects - especially the hardware projects - cost a lot of time and money. Of course I do this because I enjoy it, but if you appreciate it that I share these information with you, I would be happy about a small donation to the coffee box. 🙂