Introduction

This document discusses how to use the Network Co-Processor example application.

The NCP example is intended to be used with a host processor connected through UART or SPI. This example is setup to connect with the UART interface over the XDS110 USB-to-UART. The NCP uses the Spinel protocol to communicate to the host. The NCP can be used with the wpantund or border router packages from OpenThread.

Hardware Prerequisites

2 x CC2652 LaunchPads
1 x Linux computer

Software Prerequisites

Code Composer Studio(CCS) v7.3 or higher

Functional Description

Software Overview

This section describes software components and the corresponding source file.

Application Files

main.c: The main entry point for the example. Creates and starts the tasks for operating the OpenThread stack and NCP example.
ncp.c: Instantiation of Network Co-Processor object and heartbeat LED loop.
otstack.c: OpenThread stack instantiation and processing.
task_config.h: Defines RTOS task priorities and call stack sizes.

Example Application

This application provides an interface for a host system to control the OpenThread networking stack.

A full example of the NCP working with a host processor can be found in the Border Router Repository. This will create a border router on the host processor that allows off-mesh commissioning. Information on building the border router can be found on openthread.io.

Another example application to control the NCP can be found in OpenThread’s wpantund repository. This must be built on your Linux host PC before using this NCP example. Information on building wpantund can be found in the INSTALL.md.

Usage

This section describes how to set up and run the NCP Example Application. It is assumed that you have installed wpantund on the host Linux machine.

Buttons

BTN-1 + BTN-2 at boot: A factory reset of the non-volatile storage is performed. This must be pressed at the start of the OtStack_task function.

Display

There is no display for the NCP example application.

Setting up the Thread Network

This section describes how to set up a Thread network.

NOTE: It is assumed that you have also built a CLI example.

On the CLI example; set the channel and panid, then start the OpenThread stack.


> channel 14
Done
> panid 0xface
Done
> ifconfig up
Done
> thread start
Done
> state
detached
> state
leader
>

The first device has started a Thread network on channel 14 with panid 0xface.

NOTE: It is assumed that you have installed wpantund according to the OpenThread instructions.

Your LaunchPad may present its data port on /dev/ttyUSB1 instead of /dev/ttyUSB0. This can be set in the configuration file for wpantund.

On your host Linux PC start the wpan tunnel daemon.

$ sudo /usr/local/sbin/wpantund -o NCPSocketName /dev/ttyUSB0

Open another terminal and start the wpan control application. Then scan for networks and join the OpenThread network started by the CLI example above.

$ sudo /usr/local/bin/wpanctl
wpanctl:wpan0> scan
   | Joinable | NetworkName        | PAN ID | Ch | XPanID           | HWAddr           | RSSI
---+----------+--------------------+--------+----+------------------+------------------+------
 1 |       NO | "OpenThread"       | 0xFACE | 12 | DEAD00BEEF00CAFE | CA3E7FFCA19D3633 |  -45
wpanctl:wpan0> join -T r -p 0xface -x dead00beef00cafe -c 12 OpenThread
Joining "OpenThread" DEAD00BEEF00CAFE as node type "router"
Successfully Joined!
wpanctl:wpan0>

Open another terminal to ensure that the interface settings have been registered.

NOTE: Interfaces other than loopback and wpan elided by the “SNIP”.

$ ifconfig

----- 8< ----- SNIP ----- 8< -----

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:753 errors:0 dropped:0 overruns:0 frame:0
          TX packets:753 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:67805 (67.8 KB)  TX bytes:67805 (67.8 KB)
wpan0     Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
          inet6 addr: fe80::18d6:da3a:cc8f:1b46/64 Scope:Link
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1280  Metric:1
          RX packets:1 errors:0 dropped:0 overruns:0 frame:0
          TX packets:7 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500
          RX bytes:73 (73.0 B)  TX bytes:448 (448.0 B)

Pinging between the CLI examples

Once you have setup the network as above, you can ping between the NCP example and the CLI example nodes. Here we ping the IPv6 all nodes multicast address, and get a response from the CLI’s link local address.

NOTE: Since we are using link local prefixes, it is necessary to specify the link to send the packet on.

$ ping6 -c 4 -I wpan0 ff02::1
PING fe80:0:0:0:4c7:6d8b:f8cd:9ada(fe80::4c7:6d8b:f8cd:9ada) from fe80::18d6:da3a:cc8f:1b46 wpan0: 56 data bytes
64 bytes from fe80::4c7:6d8b:f8cd:9ada: icmp_seq=1 ttl=64 time=33.5 ms
64 bytes from fe80::4c7:6d8b:f8cd:9ada: icmp_seq=2 ttl=64 time=33.7 ms
64 bytes from fe80::4c7:6d8b:f8cd:9ada: icmp_seq=3 ttl=64 time=34.2 ms
64 bytes from fe80::4c7:6d8b:f8cd:9ada: icmp_seq=4 ttl=64 time=33.4 ms
--- fe80:0:0:0:4c7:6d8b:f8cd:9ada ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 33.439/33.756/34.280/0.366 ms
$

Network Co-Processor Example Application

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