Error on esptool.py: A fatal error occurred: Invalid head of packet ('\xe0')

[leopck]

I just pulled your latest commit and make the application, it seems that I'm having this issue on my Ubuntu 16.04 machine to burn into my NodeMCU

esptool.py v1.2-dev
Connecting...
Running Cesanta flasher stub...

A fatal error occurred: Invalid head of packet ('\xe0')

I checked the user.cfg and found the issue (for me at least) to be FWBURNFLAGS = -b 1000000 after changing this to FWBURNFLAGS = -b 115200 or ``FWBURNFLAGS = -b 1500000` I can burn into my NodeMCU nicely.

Does FWBURNFLAGS = -b 1000000 work for you?

and saw the esp82xx really great job there!

[cnlohr]

-b 1000000 works for me, but so does 1,500,000. Perhaps we should leave this issue here for others to chime in!

I know I'm weird. I use $0.90 USB to serial adapters.. http://www.electrodragon.com/product/usb-ttl-serial-ch340-board/

[leopck]

So here's some update, I took some of the USB-Serial I have around and tested and you're right. Somehow it works very nicely with CH340, PL-2303HX and FTDI232 however, testing again using the CP2102, it doesn't work and gives that error Invalid head of packet ('\xe0') hence, the NodeMCU that is also based on CP2102 is also showing this error.

Not a big issue, just change the FWBURNFLAGS = -b 115200 or FWBURNFLAGS = -b 1500000. If someone else can verify this then we can close this.

[john7doe]

I can confirm that changing the setting to 115200 helped me. Using a CP2102 based dongle on osx 10.11.3

[cnlohr]

I think I'll leave this issue open forever :-p

[umotesla]

I can confirm this always happens with CP2102, while perfectly working with FTDI

[cnlohr]

Yep. 1500000 vs 1000000 vs 2000000 baud. When you get the crazy high speeds, it is device-dependent.

[alkopop79]

Where can I find the user.cfg file on Mac OS X?

[elasticdotventures]

Just wanted to chime in that by further reducing the baud rate from 115200 to 57600 it solved a similar issue:

Chip is ESP32D0WDQ6 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
MAC: xx:xx:xx:xx:xx
Uploading stub...

A fatal error occurred: Invalid head of packet (0x65)

[gardendave]

thanks for leaving this open.
115200 worked for me.

[FlackMonkey]

Confirm to have issue, and solved by 115200 flashing speed for ESP32 (TTGO mini T7 v1.3)

[reppr]

Same issue on Geekworm KE-WROVER-C20 EASY KIT ESP32_WROVER 8MB PSRAM
fiddling with the boot button (labeled "USER" on this board) did not help
upload speed 115200 works well