Netduino 2 and Dfrobot GSM/GPS Shield

Greetings! This is my first post here, and as a Netduino newbie I'm looking forward to learning and sharing.

I'm working on a Netduino project which includes a Dfrobot GSM/GPS shield. I've completed the obligatory 'blinky' application and can edit and deploy code successfully from Visual Studio across the USB cable to my Netduino 2.

I've now added the the GSM/GPS shield, and have hit a wall. Specifically, I'd like to use a Windows 8 terminal program to send AT commands to the GSM/GPS shield via the Netduino 2, but there are no COM ports (physical or virtual) showing in Windows Device Manager, so none of the terminal programs work.

Can the PC->Netduino USB connection be used for serial comms to the shield, or do I need a FTDI Serial 232 USB Cable to wire directly onto the shield? Is there a better way to accomplish this?

Of course, in time the Netduino application will be sending the AT commands to the dfrobot shield, but for now I'd like to 'play' a bit using a terminal program

Any help/suggestions gratefully received.

Netduino2.JPG 104.38KB 1 downloads

I just bought a discounted Seeed Gprs at Radio Sack,
http://www.seeedstud...erface_Function
I now find that Seeed is selling a new model, but the basic functionality is the same as the old one.

The serial setup is different from yours, but I think they are doing the same thing. I have mine with the jumpers set to hardware. The shield is plugged in to the Netduino and Netduino is directly talking to the module via COM1. If you want to talk to the module from a PC terminal, configure yours for hardware, but don't plug it in to the Netduino.and take power externally. Then connect a USB-TTL cable to D0, D1 on the shield. The USB to RS232 cable you linked is wrong for this application. You might look at these depending upon the versatility you want ( you can get a cheaper USB to TTL adapter on ebay),

https://www.sparkfun.../products/12977

https://www.sparkfun.../products/11736

My driver in VB seems to working ok with simple commands,

        SeeedGprs.SendReceiveCmd("AT") 'can communicate
        Debug.Print("CmdSent: " & SeeedGprs.CmdSent)
        Debug.Print("CmdAnswer: " & SeeedGprs.CmdResponse)
        Thread.Sleep(400)
        SeeedGprs.SendReceiveCmd("AT+COPS?", , 400) 'Carrier info
        Debug.Print("CmdSent: " & SeeedGprs.CmdSent)
        Debug.Print("CmdAnswer: " & SeeedGprs.CmdResponse)
        Thread.Sleep(400)
        SeeedGprs.SendReceiveCmd("AT(+CSQ)") 'signal quality
        Debug.Print("CmdSent: " & SeeedGprs.CmdSent)
        Debug.Print("CmdAnswer: " & SeeedGprs.CmdResponse)


CmdSent: AT
CmdAnswer:  OK 
CmdSent: AT+COPS?
CmdAnswer: PS: 0,0,"T-Mobile"  OK 
CmdSent: AT(+CSQ)
CmdAnswer: OR

To go much further, I need an activated SIM card. The phones I have use a micro SIM and these modules take a standard size. I guess the answer is to just use the carrier for a micro SIM in in an activation kit.