But cannot debug it and probably cannot flash either.
When I plug in module-s lower USB I see COM port (USB-SERIAL CH340) in device manager. So I selected “Bootloader + GDB Stub” debug method, specified COM port. When I try to run HTTP sample, it first successfully compiles. Than, I see blue led flashing synchronously with programming progress. It stops flashing when progress stops, and continues with progress. But, than I see “Reply contains invalid hex digit NN” (where NN is random decimal number, I saw at least ten different) and nothing happens. Also, when I reset device RGB test starts over, so nothing was actually flashed.
Do you see the programming progress bar while VisualGDB is programming the module? If yes, the connection is OK and the problem is with the SPI FLASH.
We have received feedback that some of the modules come with very unreliable FLASH chips that have troubles being reprogrammed. We would recommend getting a dev board from Olimex as they seem to be using better SPI FLASH chips.