Getting started with the network-socket API

This is a quick example of a simple HTTP client program using the network-socket API that Mbed OS provides.

The program brings up an underlying network interface, and uses it to perform an HTTP transaction over a TCPSocket.

Selecting the network interface

This application is able to use any network inteface it finds. Please see the Mbed OS documentationg for selecting the default network interface.

For example, building on Ethernet enabled boards, you do not do any configuration.

Building for WiFi boards, you need to provide SSID, password and security settings in mbed_app.json as instructed in the documentation. For example, like this:

{
    "target_overrides": {
        "*": {
            "platform.stdio-convert-newlines": true,
            "target.network-default-interface-type": "WIFI",
            "nsapi.default-wifi-security": "WPA_WPA2",
            "nsapi.default-wifi-ssid": "\"ssid\"",
            "nsapi.default-wifi-password": "\"password\""
        }
    }
}

Building for boards that have more that one network interface, you might need to override target.network-default-interface-type variable.

Building

mbed compile -t <toolchain> -m <target>

For example, building for K64F using GCC: mbed compile -t GCC_ARM -m K64F

Expected output

Note: The default serial port baud rate is 9600 bit/s.

IP address: 10.118.14.45
Netmask: 255.255.252.0
Gateway: 10.118.12.1
sent 39 [GET / HTTP/1.1]
recv 173 [HTTP/1.1 200 OK]
External IP address: 217.140.111.135
Done

Documentation

More information on the network-socket API can be found in the mbed handbook.

Troubleshooting

If you have problems, you can review the documentation for suggestions on what could be wrong and how to fix it.