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2.1 Network & Bluetooth Configuration

This section mainly introduces the methods for modifying the wired and wireless network configurations of the development board.

Wired Network​

Video: https://www.youtube.com/watch?v=omaAU6sab2A&list=PLSxjn4YS2IuFUWcLGj2_uuCfLYnNYw6Ld&index=8

The default wired network configuration of the development board uses static IP configuration, and the initial IP address is 192.168.1.10. Users can switch between static and DHCP modes by the following methods.

Modifying Static IP Configuration​

The development board's static network configuration is saved in the /etc/network/interfaces file. By modifying the address, netmask, gateway, and other fields, the static IP configuration can be modified. metric is the network priority configuration, setting it to 700 is to lower the priority of the wired network. When both wired and wireless networks are enabled, the wireless network will be prioritized. For example:

sudo vim /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto eth0
iface eth0 inet static
    address 192.168.1.10
    netmask 255.255.255.0
    gateway 192.168.1.1 
    metric 700

After the modification is completed, enter the command sudo restart_network on the command line to make the configuration take effect.

Modifying DHCP Configuration​

DHCP (Dynamic Host Configuration Protocol) is usually applied in local area network environments. Its main function is centralized management and allocation of IP addresses, allowing hosts in the network environment to dynamically obtain IP addresses, gateway addresses, DNS server addresses, and other information, thereby improving the utilization of addresses.

The development board's DHCP network configuration is saved in the /etc/network/interfaces file. By modifying the relevant configuration of eth0, the DHCP mode can be modified. For example:

sudo vim /etc/network/interfaces
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
metric 700

After modifying, enter the sudo restart_network command in the command line to make the configuration take effect.

Modify MAC address configuration​

If you need to modify the default MAC address of the development board, you can add pre-up configuration information in the /etc/network/interfaces file to specify the MAC address you need, for example:

sudo vim /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto eth0
iface eth0 inet static
    address 192.168.1.10
    netmask 255.255.255.0
    gateway 192.168.1.1 
    pre-up ifconfig eth0 hw ether 00:11:22:9f:51:27

After modifying, reboot to make the configuration take effect.

Wireless Network​

Video: https://www.youtube.com/watch?v=KrlTudL0_JE&list=PLSxjn4YS2IuFUWcLGj2_uuCfLYnNYw6Ld&index=7

The development board integrates a 2.4GHz wireless WiFi module, which supports Soft AP and Station modes, and runs in Station mode by default. The following introduces how to use the two modes.

Station Mode​

In Station mode, the development board as a client and accesses the router's wireless hotspot for internet connection.

  • For users of Ubuntu Desktop version, you can click on the Wi-Fi icon in the upper right corner of the desktop, select the corresponding hotspot, and enter the password to complete the network configuration, as shown in the figure below:

image-wifi-config

  • For users of Ubuntu Server version, you can complete the wireless network configuration through the command line, following these steps:

  1. Use the sudo nmcli device wifi rescan command to scan for hotspots. If you get the following message, it means scanning is too frequent and you need to try again later:

    root@ubuntu:~# sudo nmcli device wifi rescan
    Error: Scanning not allowed immediately following previous scan.

  2. Use the sudo nmcli device wifi list command to list the scanned hotspots.

  3. Use the sudo wifi_connect "SSID" "PASSWD" command to connect to the hotspot. If you get the following message, it means the network connection is successful:

    root@ubuntu:~# sudo wifi_connect "WiFi-Test" "12345678" 
    Device 'wlan0' successfully activated with 'd7468833-4195-45aa-aa33-3d43da86e1a7'.
tip

If you receive the following message after connecting to the hotspot, it means the hotspot is not found. You can execute the sudo nmcli device wifi rescan command to rescan and reconnect.

root@ubuntu:~# sudo wifi_connect "WiFi-Test" "12345678" 
Error: No network with SSID 'WiFi-Test' found.

Soft AP Mode​

By default, the development board's wireless network runs in Station mode. To use the Soft AP mode, please follow the steps below for configuration.

  1. Install hostapd and isc-dhcp-server

    sudo apt update
    sudo apt install hostapd
    sudo apt install isc-dhcp-server

  2. Run the command sudo vim /etc/hostapd.conf to configure the hostapd.conf file, focusing on the following fields:

    interface=wlan0 # The network card used as an AP hotspot
    ssid=Sunrise # WiFi name
    wpa=2 # 0 for WPA, 2 for WPA2, usually 2
    wpa_key_mgmt=WPA-PSK # Encryption algorithm, usually WPA-PSK
    wpa_passphrase=12345678 # Password
    wpa_pairwise=CCMP # Encryption protocol, usually CCMP
    • For an open hotspot configuration, add the following content to the hostapd.conf file:
    interface=wlan0
    driver=nl80211
    ctrl_interface=/var/run/hostapd
    ssid=Sunrise
    channel=6
    ieee80211n=1
    hw_mode=g
    ignore_broadcast_ssid=0
    • For a hotspot with a password, add the following content to the hostapd.conf file:
    interface=wlan0
    driver=nl80211
    ctrl_interface=/var/run/hostapd
    ssid=Sunrise
    channel=6
    ieee80211n=1
    hw_mode=g
    ignore_broadcast_ssid=0
    wpa=2
    wpa_key_mgmt=WPA-PSK
    rsn_pairwise=CCMP
    wpa_passphrase=12345678

  3. Configure the isc-dhcp-server file as follows:

    • Execute sudo vim /etc/default/isc-dhcp-server to modify the isc-dhcp-server file and add the following definition for the network interface:
    INTERFACESv4="wlan0"
    • Execute sudo vim /etc/dhcp/dhcpd.conf to modify the dhcpd.conf file and uncomment the following fields:
    authoritative;
    • Then, add the following configuration to the end of the /etc/dhcp/dhcpd.conf file:
    subnet 10.5.5.0 netmask 255.255.255.0 { #network and subnet mask
    range 10.5.5.100 10.5.5.254;#IP range available
    option subnet-mask 255.255.255.0; #subnet mask
    option routers 10.5.5.1;#default gateway
    option broadcast-address 10.5.5.31;#broadcast address
    default-lease-time 600;#default lease time in seconds
    max-lease-time 7200;#maximum lease time in seconds
    }

  4. Stop the wpa_supplicant service and restart wlan0

    systemctl stop wpa_supplicant

    ip addr flush dev wlan0
    sleep 0.5
    ifconfig wlan0 down
    sleep 1
    ifconfig wlan0 up

  5. Start the hostapd service as follows:

    • Execute the command sudo hostapd -B /etc/hostapd.conf
    root@ubuntu:~# sudo hostapd -B /etc/hostapd.conf
    Configuration file: /etc/hostapd.conf
    Using interface wlan0 with hwaddr 08:e9:f6:af:18:26 and ssid "sunrise"
    wlan0: interface state UNINITIALIZED->ENABLED
    wlan0: AP-ENABLED
    • Configure the IP and subnet of wireless interface wlan0 using the ifconfig command, make sure it matches the configuration in the third step
    sudo ifconfig wlan0 10.5.5.1 netmask 255.255.255.0
    • Finally, start the dhcp server. Clients connecting to the hotspot will be assigned an IP address from 10.5.5.100 to 10.5.5.255
    sudo ifconfig wlan0 10.5.5.1 netmask 255.255.255.0
    sudo systemctl start isc-dhcp-server
    sudo systemctl enable isc-dhcp-server

  6. Connect to the hotspot on the development board, for example, sunrise

    image-20220601203025803

  7. If you need to switch back to Station mode, you can do it as follows:

    # Stop hostapd
    killall -9 hostapd

    # Clear the address of wlan0
    ip addr flush dev wlan0
    sleep 0.5
    ifconfig wlan0 down
    sleep 1
    ifconfig wlan0 up

    # Restart wpa_supplicant
    systemctl restart wpa_supplicant

    # Connect to the hotspot, for specific operation, please refer to the previous section "Wireless Network"
    wifi_connect "WiFi-Test" "12345678"

DNS Server​

Video: https://www.youtube.com/watch?v=YCNFSC7LpCY&list=PLSxjn4YS2IuFUWcLGj2_uuCfLYnNYw6Ld&index=6

DNS (Domain Name Server) is a server that converts domain names to their corresponding IP addresses.

The DNS configuration on the development board is managed through the /etc/systemd/resolved.conf file. Users can modify this file to configure DNS settings. The steps are as follows:

  1. Modify the resolved.conf file and add the DNS server address, for example:

    DNS=8.8.8.8 114.114.114.114

  2. Enable DNS configuration using the following commands:

    sudo systemctl restart systemd-resolved
    sudo systemctl enable systemd-resolved
    sudo mv /etc/resolv.conf  /etc/resolv.conf.bak
    sudo ln -s /run/systemd/resolve/resolv.conf /etc/

2.2 System Updates​

For system security and stability considerations, it is recommended for users to update the system using the apt command after the installation.

The software source list for the apt command is stored in the /etc/apt/source.list file, and it is necessary to update the package list with the apt command before installing software.

First, open the terminal command line and enter the following command:

sudo apt update

Next, upgrade all installed software packages to the latest version with the following command:

sudo apt full-upgrade
tip

It is recommended to use the full-upgrade option instead of the upgrade option, so that dependency packages will also be updated when related dependencies change.

When running the sudo apt full-upgrade command, the system will prompt for data download and disk space usage. However, apt does not check if there is enough disk space, so it is recommended for users to manually check with the df -h command. In addition, the deb files downloaded during the upgrade process will be saved in the /var/cache/apt/archives directory. Users can use the sudo apt clean command to delete cache files and free up disk space.

After executing the apt full-upgrade command, it may be necessary to reinstall drivers, kernel files, and some system software. It is recommended for users to manually restart the device to apply the updates, using the following command:

sudo reboot

Bluetooth​

Video: https://www.youtube.com/watch?v=Ov8mL8P_yUY&list=PLSxjn4YS2IuFUWcLGj2_uuCfLYnNYw6Ld&index=10

Initialization​

The Bluetooth function on the development board is not enabled by default. You need to execute the /usr/bin/startbt6212.sh script to initialize it. The script completes the following tasks:

  • Reset the Bluetooth
  • Create the messagebus user and group, which are required for the operation of the dbus-daemon program
  • Run brcm_patchram_plus to load the Bluetooth driver and firmware
  • Continuously check if the /sys/class/bluetooth/hci0 directory exists to confirm that the Bluetooth driver is running properly
  • The appearance of Done setting line discpline indicates that the Bluetooth has been successfully enabled
  • Execute hciconfig hci0 up to bring up the Bluetooth Link
  • Execute hciconfig hci0 piscan to perform Bluetooth scanning (this step can be excluded depending on the situation)

The log after the successful execution of the script is as follows:

image-20220601172145987

In addition, users can use the following command to check if the Bluetooth process is functioning properly:

ps ax | grep "/usr/bin/dbus-daemon\|/usr/lib/bluetooth/bluetoothd"
/usr/bin/dbus-daemon

/usr/lib/bluetooth/bluetoothd

Network Configuration and Connection​

Execute sudo bluetoothctl to enter the interactive mode of Bluetooth configuration. If device information similar to the image below appears, it means that the Bluetooth has been recognized. Then, use show to view the Bluetooth information and pay attention to the powered and discoverable statuses of the Bluetooth.

image-20220601172604051

Execute power on to enable the Bluetooth, as shown in the image below:

image-20220601172501882

In order to make the Bluetooth discoverable to nearby devices, execute discoverable on to enable the Bluetooth and open the discoverable attribute of the Bluetooth, as shown in the image below:

image-20220601172648853

Now, you can use a mobile phone or computer to scan for the Bluetooth device with the name ubuntu, as shown in the image below:

image-20220601175322650

Next, test the active scanning function of Bluetooth. In the interactive interface of bluetoothctl, enter scan on to enable active scanning. It will periodically print nearby devices. You can see that my mobile phone device has been discovered. Enter scan off to disable the scanning function and summarize the scanned Bluetooth devices.

image-20220601154131158

image-20220601154253947

Then comes the pairing with other Bluetooth devices:

  • Pairing command: pair [targetMAC], after entering this command, follow the prompts to enter yes, and the remote Bluetooth device will select the Pair option to complete the pairing.

  • After successful pairing, you can use trust [targetMAC] to automatically connect next time.

image-20220601154414717

After the above operations, the basic functions of Bluetooth scanning and pairing are completed. For more functions, please refer to the official help documentation of BlueZ.