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USB Huawei modem with stm32f407

hilwan
Associate II
Posted on July 26, 2017 at 10:04

Hi,

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: 

https://www.keil.com/pack/doc/mw/USB/html/host_cust_tutorial.html

 

. 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: ~�}♯�!}!} } }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 ?

Best regards,

#usb-modem #stm32f407
2 REPLIES 2
Danish1
Lead II
Posted on July 26, 2017 at 22:26

That 'garbage' looks to me like point-to-point-protocol-over-serial to me.

https://en.wikipedia.org/wiki/Point-to-Point_Protocol

Hope this helps,

Danish

hilwan
Associate II
Posted on July 28, 2017 at 10:26

Thank you Danish, i still have the Timeout problem from Notify Callback function. Because my Modem is in USB and the Stack network of Keil uses an UART bridge to send and receives AT commands.

I want to know if someone has an experience with this.

Best regards,