OK, I managed to get the following ESP32-S3 Devkit board to upload. https://www.ebay.com/itm/405020742821 The trick is that on the Arduino IDE, one must set tools/USB CDC On Boot to enabled. Default is disabled. This is because the S3 will disconnect the USB connection after upload, and hence serial ...

Unfortunatelly it does not work for me

My error. Please see my corrected post.

But it will not work without a flash.

I hear you ESP_Sprite. Just that when I power up a board, the flashed code invariably starts running. So the processor should be able to detect that a boot has been requested by the UART at any time and get into boot mode? I have no idea how it gets into boot mode remotely. I am assuming a certain ...

Very interesting. Could ESP32 have a bit of firmware in the ROM to check for all these parameters, and if all are in place, accept the command to get into boot mode? And if the check fails, to blink a code on a LED? This would take an Espressif engineer one day to code, while saving millions of ...

Try a different power supply - one that is sourced from batteries. Like 2S 18650 down converted to 5V.

I have even drained a 2S li-ion down to 7.0 V and successfully powered a 5V dev board without down conversion.

Do 7V at your own risk please.

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

(correction): Install 10K resistor parallel to C20.

Increase C20 to 10 uF or larger.

Hope this helps. Please let me know.

Mystery solved!

I managed to get the board https://www.ebay.com/itm/404536226926 to boot after all!!!

You had suggested a 10 uF capacitor between EN pin and ground. The only way to get this to boot was in addition putting a 10K resistor in parallel to the capacitor. And only 10K works. 9K or 12K ...

Hi ESP_Sprite,

I managed to get the board https://www.ebay.com/itm/404536226926 to boot!!!

You had suggested a 10 uF capacitor between EN pin and ground. The only way to get this to boot was in addition putting a 10K resistor in parallel to the capacitor. And only 10K works. 9K or 12K do not work ...

Update to my last post (item 404536226926):

I obtained the driver from the CP1202 manufacturer and installed it. So now Window recognizes the COM port, and IDE can connect to it. But it cannot upload after many dots: "uploading error exit status 2". I tried pressing all combination of boot and RST ...

The following board appears to be a CP2102. When connected, W11 beeps and shows "CP2102 USB to UART Bridge Controller", with an exclamation warning. So I suppose the driver is not installed.

https://www.ebay.com/itm/404536226926

When "update driver" is clicked W11 says Windows cannot find ...