we making new project with esp32 in it. with initially installed 32mhz it does not started even in bootloader mode. with 26 and 40mhz generators we were succeeded to start and program.
My question is which frequencies are allowed and prefered for esp32?

WARNING: Failed to communicate with the flash chip, read/write operations will fail. Try checking the chip connections or removing any

Ahrg, I could have spotted that in the schematics. You can't program the flash because there is no flash to program: The ESP32-D0WD does not come with in ...

I am not sure if I am answering your question, but I managed to get a WROOM 32 into boot mode as follows:

Connect R21 to GND (and not 3V3).

Increase C20 to 10 uF or larger.

Hope this helps. Please let me know.

Unfortunatelly it does not work for me

Here is my flash log:

esptool.py v4.2.1
Serial port /dev/ttyUSB0
Connecting....
Chip is ESP32-D0WDQ6 (revision 0)
Features: WiFi, BT, Dual Core, Coding Scheme None
Crystal is 40MHz
MAC: 24:0a:c4:80:27:0c
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
WARNING ...

Can not flash my new project on ESP32-D0WDQ6 (revision 0).
Assume that one of specific gpio was used. Peale suggest which one. Schematic attached to the ticket. GPIO5 and MTMS pin are removed already, but result is the same. Can some one give any advice?