Esp-wroom-32 devkit board not booting without pressing the EN button


after flashing the esp-wroom-32 board and configer it for mdash the device comes online without problems.
However every time when we reboot the esp the device is not booting anymore. (I do a power off power on)
Only after pressing the EN button after a power ON the esp is booting again and comes online.
Tried with 2 different boards, both have the same behavior.

mos flash --port com24
mos wifi xxxxx xxxxx
mos config-set dash.token=xxxxxxxxxxxxxxx

Did some tests with ui:
after power off/on the device is not connecting to mos ui either

E0408 15852 serial.go.273] No response to handshake. Is COM24 the right port? Is rpc-uart enabled?

when pressing the EN button I see the device booting and then MOS can connect.

Any idea how to solve this problem?

Are you using a development board, or a WROOM32 module (which is not supposed to be used stand-alone) ?

yes, we use these boards:

(bought from Olimex)

That’s something unexpected.
These boards are quite widespread, and so far such issues were not reported.
Try to boot a bare board. If that does not help, use a different board.

The ESP32-DevKitC is used by everyone and their brother - it should certainly work for you.

Programming and booting are controlled by the EN and IO0 pins. When you download via USB, the on-board USB/UART bridge (SiLabs CP2102) will drive the DTR/RTS pins which, in turn, control EN & IO0.

If your hardware is OK then the download routine should be using hardware flow control to manipulate the state of the DTR/RTS pins. I would expect this to be baked into the mos flash tool.

Try using a simple Aurdino sketch and download it onto your EVB. If you have the same problem there, then I would take a closer look at your hardware pin configuration/connections. Make sure the EN and IO0 pins on your EVB are not connected to anything.