ESP8266 Community Forum

- Sun Jan 07, 2018 11:57 am #72942 First try to erase the flash completely to ensure it doesn't contain any remains from a previous SDK. The docs say to use the following command http://nodemcu.readthedocs.io/en/dev/en ... #esptoolpy:

Code: Select allesptool.py --port <serial-port-of-ESP8266> erase_flash

Then flash again and add the option "-fm dio" just to be on the safe side. If it works now then you can try again flashing with "-fm qio". QIO is favorable in terms of flash memory access performance but might not work on all modules out there.

- Tue Jan 09, 2018 3:19 pm #73017 Hi again!
So: It didn't work, but after erasing firmware I could always see the COM port on my computer, even after reset not in flash mode. And after flashing firmware with this command:

Code: Select allesptool.py --port COM7 write_flash 0x0000 nodemcu-master-21-modul
es-2017-12-29-14-50-13-float.bin -fm dio

I couldn't see The COM port again.

- Tue Jan 09, 2018 5:17 pm #73021 the comport is only matter of the usb-serial chip and not related to the esp8266 chip in any way.
even if tghe esp chip be removed from the board, the com port would be present.
So it is most likely something with your OS, the driver, the cable or the usb-serialchip