I'm working on application that uses a USB HUAWEI MU709 modem with STM32F407. First off all, i used the usb stack from keil to implement the CDC mode: USB Host Custom Class . I follow the USB PL2303 example to make my own.
The usb communication works fine.
I’m trying to get PPP working.for that, i used the network stack from kiel and modem Driver functions from MDK Middleware for IPv4 and IPv6 Networking. There is also an example with driver modem form keil for standard modem, i flowed it to make my own.
So, I proceed as follows:
1) I call netInitialize(); to intiailise the network stak
2) In a thread i called netPPP_Connect("*99***1#", "", ""); to communicate with modem. This function call a callback called Notify specified in the Modem driver. In this callback, i implement my own AT command as in the example from keil.
I have two problems:
The first one is with this Notify callback, I always have a timeout response even if the modem responds correctly.
The second one :
I successfully configured everything. Except that I’m getting garbage after “ATD” . I get the response CONNECT 21600000, then after a moment, I get something like this: ~ÿ}#À!}!} } }4}"}&} } } } }'}"}(...".
I don't understand the meaning of this garbage?
Can you please give me an explanation, please, if you have experience with this kind of modems ?