ESP32 Forum

Hello everyone,

I'm running into an odd issue that I'm not sure how to fix.
When I attempt to flash to the ESP32, often times it will interrupt at random percentages during the flashing.
My baudrate is set to the default of 115200 baud. I'm running Ubuntu in a VM, the USB settings are set to USB 3.0. I have an external power supply connected to the chip, and I'm using an USB cable to flash the device, the ESP32-WROVER-KIT.
The device is placed on a ESD-safe mat, which is connected to my computer case, allowing it to be ground.

Looking at the bash log when I execute the "make flash" command, everything works fine, until at random it'll quit entirely for a reason I don't quite understand.
At the moment of writing, the process is stuck at:
Writing at 0x00024000... (54 %)
There are no error messages, and when this happens, I can see the RX LED (I'm assuming it's the red one, according to the datasheets) turn off. I'm assuming connection is still established, because there are no error messages.
I'm quite confused at this odd problem, and I hope there is a solution for this oddity, because I'm quite at wit's end.
Thank you for reading.

Can you try flashing in your host OS, not in a VM? Could be that your virtualization is messing things up. Esp-idf is available for MacOSX and Windows as well, in case you did not know.

Thank you for the reply,

Interestingly enough it seems this occurs entirely at random. I haven't had this issue happen to me again after rebooting my computer. I'm still at loss as to why it happens though. If it's something that happens inside the hardware itself, then of course I wouldn't know

The flash process seems to be pretty time-critical. If I don't have a perfect electrical connection when it starts it will never start, for instance, have to ctrl-c and restart 'make flash.'

Hello,

most probable it is related to the USB cable connection. Try using higher quality cable. It could also be observed when the current/voltage is at a limit.

Maybe also device temperature and the quality of the usb uart chip.
For example my DOIT board off aliexpress is pretty temperamental, when it is cold it will flash and when its warm it will have a 1/3 chance of flashing. It will flash at speeds 115200 921600 that makes no difference. My Pycom LoPy however does not get warm, ~20 degrees C colder than the DOIT and flashes at any speed and no errors even at 2mbaud.