File content as of revision 10:5819b0a88423:

# Example mesh application for mbed OS

This application is the simplest one to utilize our mesh networking stack. It just joins your device to the unsecure *6LoWPAN-ND* network.

## Setup

### Download the application

```
mbed import mbed-os-example-mesh-minimal
cd mbed-os-example-mesh-minimal
```

### Change the channel settings (optional)

See the file `mbed_app.json` for an example of defining an IEEE 802.15.4 channel to use.

### Compile the application

```
mbed compile -m K64F -t GCC_ARM
```

A binary is generated at the end of the build process.

### Connect the RF shield to the board

By default, we are using the Atmel AT86RF233 and it can be purchased [here](https://firefly-iot.com/product/firefly-arduino-shield-2-4ghz/). Place the shield on top of your board and power it up.

### Program the target

Drag and drop the binary to the target to program the application.

### Update the firmware of the border router

You can read the instructions on updating the firmware of your K64F working as 6LoWPAN border router [here](https://github.com/ARMmbed/mbed-os-example-client#mbed-gateway).

Please do not forget to connect the Ethernet cable between the border router and your home/office router. Then power up the board.

## Testing

As soon as both the border router and the target are up and running you can verify the correct behaviour. Open a serial console and see the IP address obtained by the device.

<span class="notes">**Note:** This application uses a baud rate of 115200.</span>

```
connected. IP = 2001:db8:a0b:12f0::1
```

You can use this IP address to `ping` from your PC and verify that the connection is working correctly.

### Changing the radio driver (optional)

To run a 6LoWPAN-ND network, you need a working RF driver for Nanostack. This example uses the Atmel AT86RF233 by default. 

To change the RF driver:

1. Uninstall the Atmel RF driver.

        mbed remove atmel-rf-driver

2. Install the new driver. (For example, for the FRDM-CR20A radio shield based on the MCR20A device.)

        mbed add mcr20a-rf-driver

3. Recompile your application.

        mbed compile -m K64F -t GCC_ARM

## Important Note (Multi-platform support)

mbed-OS provides the developer with total control of the device. However some defaults are always loaded if the user does not provide proper information regarding them. This becomes evident when a user switches among platforms. On some platforms a particular pin might be reserved for a particular functionality (depending upon the MCU) which thus cannot be used generally. If the ardurino form factor is not available, or the required peripherial is on a different pin, the pins values can be set manually. For example, the user can add *"atmel-rf.spi-rst": "D4"* to his/her mbed_app.json file. This will set the SPI_RST pin to D4 of the GPIO.

```json
{
    "target_overrides": {
        "*": {
            "target.features_add": ["IPV6", "COMMON_PAL"],
            "atmel-rf.spi-rst": "D4"
        }
    }
}
```

Desired work flow in such situations (if it may arise) should be:

1.  Checking the platform pinmap from [mbed Platforms](https://developer.mbed.org/platforms/).
2. Making sure that the desired GPIO pin is free by looking at the data sheet of the particular MCU. Most of the data sheets are available on  [mbed Platforms](https://developer.mbed.org/platforms/). 
3. If necessary, change the pin or pins by using the mbed -OS config mechanism. You can get more informations about the configuration system in the [documentation](https://github.com/ARMmbed/mbed-os/blob/master/docs/config_system.md)