How do you program the OS the first time? Are they already flashed with something that
gets you into AP mode that enables updating through the WiFi?
I can reliably flash the released firmware now but it does not work. I suspect that there
is already some firmware in the OS that makes it work that I am missing. Do you know
what that might be? Can you read a full copy of the flash from a working unit using
something like esptool.py?
I had assumed that the pins connected to buttons B1 and B3 were pulled up internally.
But I found a web page that said that GPIO 2 must be pulled up with a resistor to enable
programming mode. With the resistor it always works, without it it rarely works.
Perhaps it is only my unit.
I am using a CH340 which works fine now. I do have a soldered on reset switch however.
With a CP2102 you get extra pins that allow it to handle the reset. I have already ordered
one.