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A fatal error occurred: Failed to connect to ESP32: Invalid head of packet ('a')

Posted: Tue Dec 20, 2016 7:45 am
by TESTTHISONE
Hello,

I've encountered a problem with setting ESP32 Development Kit (WROOM-32)
My environment is Windows 7 (64 bits), and I followed the every step explained in the following link:
https://github.com/espressif/esp-idf/bl ... -setup.rst

After putting the device into "download mode" using Realterm --> port closed --> set as /COM3 & baud rate 115200 in menuconfig --> make flash, I get the following error:

.
.
.
esptool.py v2.0-dev
Flashing binaries to serial port /COM3 (app at offset 0x10000)...
esptool.py v2.0-dev
Connecting...

A fatal error occurred: Failed to connect to ESP32: Invalid head of packet ('a')
make: *** [/c/msys32/esp-idf//components/esptool_py/Makefile.projbuild:48: flash] Error 2


PS. For USB to UART Driver, I downloaded and installed "CP210x USB to UART Bridge VCP Drivers" for windows 7.
Link: http://www.silabs.com/products/mcu/page ... px#windows

why does this error occur, and how do I solve this issue?


Regards,

Re: A fatal error occurred: Failed to connect to ESP32: Invalid head of packet ('a')

Posted: Tue Dec 20, 2016 1:04 pm
by erhardd
Try:
bring the board in bootload-mode(hold the flash button down) till the download starts.. ;)

Re: A fatal error occurred: Failed to connect to ESP32: Invalid head of packet ('a')

Posted: Wed Dec 21, 2016 1:42 am
by TESTTHISONE
It worked. Thank you!
How come there are no single information regarding it on the datasheet...

Re: A fatal error occurred: Failed to connect to ESP32: Invalid head of packet ('a')

Posted: Wed Dec 21, 2016 2:04 am
by ESP_Angus
Glad you got this working. It's a hardware bug (with Windows & some dev boards), that we are hoping to fix in the next hardware revision.

In the meantime, I've asked the documentation team to revise the Getting Started Guide to mention this workaround.