Hardware Setup

Because of the high current that the USB dongle requires, it is not possible to power it from the Vu pin on the mbed. In the example show, an external linear regulator board has been used to provide a high current regulated 5V supply from a 9V wall adaptor. The parts shown are :

• USB A Socket
• Breadboard Power Supply
• Breadboard
• Jumper Wires
• 9V wall power supply

Hello World

This example application uses the VodafoneUSBModem and the HTTPClient interface, enabling the mbed to fetch a URL over HTTP, and print the contents.

There are various other "hello world" programs that demonstrate SMS, NTP, Socket and Websocket interfaces, as well as management commands (check balance, link status, etc). See "Resources" section below.

You'll notice that this "Hello World" program is a little more complex that others, as we're using the mbed RTOS to manage the memory and processing resources/requirement of the USB Modem driver and the TCP/IP stack.

Resources and references

Network APN

To connect to the internet you must establish a PPP connection. You can then use BSD Sockets or any high-level component (HTTP Client, NTP Client).

To establish this connection, one single function is used:

int ret = modem.connect("pp.vodafone.co.uk");

pp.vodafone.co.uk is the APN value for a Vodafone Pay as you Go SIM. Change it to the relevant value if your SIM is different:

For details please check Vodafone's dedicated page.

The variable, "ret", allows you to check whether the connection was successful or not (0 on success, a negative value on error).

Please note that the "connect" command can take a few minutes to complete in worst case scenarios, as it initializes the modem and then waits for network registration.

Other Examples

Click here to the programs that are using the NTPClient

Click here to the programs that are using the WebsocketClient