Homekit over OpenThread is supported in Gecko SDK suit 3.2 released in 2021Q2. The following two samples are provided:

• homekit_lightbulb_thread
• homekit_lightbulb_dmp

Users can try these samples after reading QSG179 and AN1327. To try homekit over OpenThread, users need to set up the OpenThread Border Router. The steps described in section 7.3 of AN1327 is outdated as the OpenThread project developped so fast.

This page will describe the steps to set up the OpenThread Border Router on RaspberryPi for homekit applications.

To test the homekit applications over OpenThread, users need to keep the homekit controller and the accessories in the same IPv6 subnet. The homekit controller could be any of the following:

• The App Home on an ios device.
• The HAT (Homekit Accessory Tester) tool on an macOS device.

Please refer to https://www.raspberrypi.com/documentation/computers/configuration.html#setting-up-a-routed-wireless-access-point for the detailed steps. As a summary, the brief steps are listed below:

1. Install AP and Management Software.

   Install hostapd which is an WiFi AP management tool:

   sudo apt install hostapd

   Enable the service, so that hostapd can start up automatically.

   sudo systemctl unmask hostapd
   sudo systemctl enable hostapd

   Install dnsmasq which is an DHCP server and DNS server:

   sudo apt install dnsmasq

   Install netfilter-persistent and its plugin iptables-persistent, so that the iptables settings can be saved.

   sudo DEBIAN_FRONTEND=noninteractive apt install -y netfilter-persistent iptables-persistent

2. Set a static IP address for the WLAN interface on the WiFi AP.
   Run command sudo vim /etc/dhcpcd.conf to modify the config file, add the following content to the end of the file.

    interface wlan0
        static ip_address=192.168.44.1/24
        static ip6_address=fd11:44::1/64
        nohook wpa_supplicant
   

3. Enable IP forwarding.
   Run command sudo vim /etc/sysctl.conf to uncomment the following lines.

   net.ipv4.ip_forward=1
   
   net.ipv6.conf.all.forwarding=1
   

4. Config DHCP and DNS services.
   Run command sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig to backup the original config file, then run command sudo vim /etc/dnsmasq.conf to create a new config file and add the following content to it.

    interface=wlan0 # Listening interface
    dhcp-range=192.168.44.100,192.168.44.200,255.255.255.0,24h
                    # Pool of IP addresses served via DHCP
    domain=wlan     # Local wireless DNS domain
    address=/gw.wlan/192.168.44.1
                    # Alias for this router
   
    enable-ra
    dhcp-range=fd11:44::1000, fd11:44::fc00, 64, 24h   
   

5. Configure the AP software.
   Run the following command to ensure the WiFi radio is not blocked by Raspberry Pi.

   sudo rfkill unblock wlan

   Run command /etc/hostapd/hostapd.conf to configure the WiFi AP.

    country_code=GB
    interface=wlan0
    ssid=NameOfNetwork   # config the SSID here
    hw_mode=g
    channel=7
    macaddr_acl=0
    auth_algs=1
    ignore_broadcast_ssid=0
    wpa=2
    wpa_passphrase=AardvarkBadgerHedgehog  # config the password here
    wpa_key_mgmt=WPA-PSK
    wpa_pairwise=TKIP
    rsn_pairwise=CCMP   
   

6. Configure the iptables to forward the IP packets between eth0 and wlan0.

   sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
   sudo iptables -A FORWARD -i eth0 -o wlan0 -m state --state ESTABLISHED,RELATED -j ACCEPT
   sudo iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT

   Then run command sudo netfilter-persistent save to save the iptable settings.

7. Connected eth0 to the internet, reboot the Raspberry Pi, then connect to the WiFi AP and check if it's working.

   • Make sure the client can get both IPv4 address and IPv6 address.
   • Make sure you can access the internet when you connect to the WiFi AP.

Please refer to https://openthread.io/guides/border-router/build.md for the detailed steps.

**!!Important:**as the bind9 service will be installed when you install the otbr, and the bind9 service has some conflict with the dnsmasq service. Here we need to stop the dnsmasq service first, then restart that after otbr installation complete.

sudo systemctl stop dnsmasq.service

As a summary, the brief steps are listed below:

1. Clone the OTBR repository:

   git clone https://github.com/openthread/ot-br-posix
   

2. Install dependencies:

   cd ot-br-posix
   ./script/bootstrap
   

3. Compile and install OTBR. As we have already set up the WiFi AP, no need to install network manager here.

   NETWORK_MANAGER=0 ./script/setup
   

4. Disable the bind9 service.

   sudo systemctl stop bind9.service
   sudo systemctl disable bind9.service
   

5. Start dnsmasq. Then restart the dnsmasq service.

   sudo systemctl start dnsmasq.service
   

!!Note:!!
Please note that the latest OTBR repo is not compatible with the RCP sample in Gecko SDK Suite. We need to build the RCP with the github repo https://github.com/openthread/ot-efr32.git. Please refer to https://github.com/openthread/ot-efr32/blob/main/src/README.md to build the RCP.

After you have flashed the RCP to the kit, please connect the kit to the Raspberry Pi, then reboot it, then verify the status of the otbr services.

Run command sudo systemctl status to check the services, and make sure the following services is running:

• otbr-agent.service
• otbr-web.service

1. On the Border Router, run command sudo ot-ctl to enter the CLI mode. Run the following command to form a thread network.

   dataset init new
   dataset commit active
   ifconfig up
   thread start
   

2. Use command state to check the status of the border router until it turns to leader. Then run command dataset to get the current dataset. e.g.

    > dataset
    Active Timestamp: 1
    Channel: 14
    Channel Mask: 0x07fff800
    Ext PAN ID: 6cfd2de9be6b9d1f
    Mesh Local Prefix: fd41:84ec:1687:17d2::/64
    Network Key: fcfbf95e4797a51dc5d5a3ef6648c725
    Network Name: OpenThread-936c
    PAN ID: 0x936c
    PSKc: 9e89301e5df4c73a14f69648071b87fd
    Security Policy: 672 onrcb
    Done   
   

3. Run the lightbulb device, run the following command to join the device.

   dataset channel 14
   dataset networkkey fcfbf95e4797a51dc5d5a3ef6648c725
   dataset commit active
   ifconfig up
   thread start
   

4. Check the IP address for the two thread devices with command ipaddr.

   > ipaddr
    fd41:84ec:1687:17d2:0:ff:fe00:fc11
    fd41:84ec:1687:17d2:0:ff:fe00:fc10
    fd41:84ec:1687:17d2:0:ff:fe00:fc38
    fd83:b10f:72f2:f77f:d358:30bf:4fc2:d065
    fd41:84ec:1687:17d2:0:ff:fe00:fc00
    fd41:84ec:1687:17d2:0:ff:fe00:a800
    fd41:84ec:1687:17d2:25d:4e4b:bd7c:2926
    fe80:0:0:0:644d:d033:d0e5:f062
    Done
   

1. Connect the iPhone/iPad to the WiFi AP of the Raspberry Pi
2. Check the IPv6 address of the iPhone/iPad. Ping the IPv6 address from the lightbulb device. Make sure the ping is OK.
3. Follow the steps of section 2.1.1 of QSG179 to test.

1. Connect the Mac to the WiFi AP of the Raspberry Pi
2. Check the IPv6 address of the Mac. Ping the IPv6 address of the lightbulb device. Make sure the ping is OK.
3. Follow the steps of section 3.5 of QSG179 to test the DMP sample.

• QSG179 homekit sdk quick start guide
• AN1327 homekit sdk configuring project
• UG493 homekit developers guide
• OpenThread Border Route Build and Configuration
• Setting up a routed wireless access point on Raspberry Pi