after a few stumbles the data flash of the mcu is working, I defined only 100 bytes of space for the configuration and identification memory like apn, port, ip, serial number etc... all this memory are available for read and write from the user usb port.

when I finish with this part I will write the code to assemble a chain of data and send every x minutes to a server (other modem connected to my pc).

soon I will make some field test and then maybe a video.