A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header

[esp1979]

Hi,

i bought a few ESP32 from MH-ET and all of them are not detected from Arduino IDE. All my other ESPs (from AZDelivery) work.

What seems strange to me is: When i plug in the AZDelivery ESPs i get a port "/dev/ttyUSB0" (that works for uploading). When i plug in the MH-ET ESP i get a "/dev/ttyACM0" (that works not). With both boards additionally i get an "/dev/ttyS0"-Port.

Is there any chance to get them working? What am i doing wrong?

I set the permission rights via
sudo chmod a+rw /dev/ttyACM0
and
sudo chmod a+rw /dev/ttyS0 already

Best wishes
Daniel