ESP8266 Community Forum

The proposed workaround of @abellisco works for me!!!
Before I tried a lot of to get rid of the "esptool.fatalerror failed to connect to esp8266 timed out waiting for packet header" but nothing worked.
So thank you very much @abellisco for posting your solution!!

I have tried all your suggestions but it has not solved my problem.
esptool.py v3.0
Serial port COM9
Connecting........_____....._____....._____....._____....._____....._____....._____
esptool.FatalError: Failed to connect to ESP8266: Timed out waiting for packet header

I tried with different cables, serial port speeds, gpio0 to gnd connected or not, pressing reset while trying to connect. None worked.
The curious thing is that I didn't have this problem at the beginning. I uploaded the blink and then my program at least one successfully! Then it started.

Finally I was able to bypass the problem! What I did was to take the board out of the breadboard and re cable the setup.
A bad ground? a cable not touching correctly the breadboard? Any of these ...

This may Help.

I was like creisy with de header error, but I found this info from the maker ( https://docs.ai-thinker.com/_media/esp8 ... ion_en.pdf )..

You must put your Wemos on Uart Download.
Important: I switched from 115,200 to 9,600 bps, to perform the downloading, else error..!!!
After downloading you have to Hard Reset.

GPIO5 GPIO0 GPIO2 MODE
1 X X SDIO/SPI WIFI
0 0 1 Uart Download
0 1 1 Flas Boot