11.8 Configuration and Connection of Bluetooth
The Raspberry Pi 3 model B provides Bluetooth functionality as standard. Therefore, without purchasing a separate device, you can easily connect to various devices supporting Bluetooth around Raspberry Pi, such as mobile devices, and do an interesting works easily.
To configure Bluetooth settings, you can use the Bluetooth menu in the [Tools] area of the Desktop window.
11.7.2 Activation and Stop with “ifconfig” Command
We used the “ifconfig” command to look up the current state of the network. However, this “ifconfig” command can also be used to activate or stop the network using “up” or “down” as an option.
The command format used to activate the network device is as follows
11.7 Activation and Stop of Network
While operating the system, you may need to stop and reactivate the network device as needed for various reasons, such as an error occuring or changes to the configuration. If the existing device is stopped, the network connection is disconnected, and the IP address that was previously assigned can not be used. When the connection is stopped and a new connection is made, the network connection is made according to the latest setting contents.
You can use several commands to stop and reactivate the Raspberry Pi system. Let’s look at each command one by one.
11.7.1 Network Activation/Stop by “ifup” and “ifdwon” Command
11.6.2 How to Set up Static IP Address in Raspberry Pi
The default setting for the IP address in the Raspberry Pi system is stored in “/etc/network/interfaces” file. Normally, the contents as follows are stored.
iface lo inet lookback
iface eth0 inet dhcp
iface wlan0 inet dhcp
wpa-ssid “wifissid”
wpa-psk “wifipassword”
11.6 Setting Static IP Address
Normally, when connecting a computer to a network, it is general that the computer is automatically assigned the IP address from the DHCP server, but the IP address for each computer can be fixed as needed. As a method for fixing IP address for a specific computer, there are method of assigning the IP address by setting “manual IP allocation” in the DHCP server and method of assigning the IP address in the individual computer.
11.6.1 How to Specify Static IP Address on DHCP Server
In a typical small network, such as a home or small office, the network is configured so that a router acts as a DHCP server. In this method, a DHCP server may specifies a fixed IP address predefined for a specific computer. Then, when the computer connects to the network, it is assigned the predefined fixed IP address. At this time, you usually use the Mac address assigned to the computer hardware to distinguish a specific computer.
11.5.2 Setting Wireless Connection with Configuration File
The default settings for the network in the Raspberry Pi system are stored in the file “/etc/network/interfaces”. In this file, you can activate the wireless connection by directly entering the settings for the wireless connection.
If you have already configured with the window Wi-Fi configuration tool, it will have the following contents, and you will need to delete all this contents.
11.5 Wireless Connection
Starting with the Raspberry Pi 3 model, Wi-Fi devices are installed by default. So you can use Wi-Fi without buying a separate device. However, to use Wi-Fi on previous Raspberry Pi models, you must purchase and install a separate USB Wi-Fi device.
To connect to the network wirelessly via Wi-Fi, you need to connect to a wireless access point, which requires Wi-Fi settings to connect wirelessly. The window in the Raspbian distribution includes a tool to simplify Wi-Fi configuration.
11.5.1 Setting Wi-Fi with Panel Menu
This section describes the settings of Wi-Fi that are installed by default from the Raspberry Pi 3 model.
11.4 Wired Network Connection
Figure 11‑1 Raspberry Pi LAN cable port
The Raspberry Pi system provides an RJ45 connector that allows you to connect a LAN cable to connect to a wired Ethernet network. If you connect a LAN cable connected to the network to the LAN port of the Raspberry Pi system, the network LED starts blinking automatically as soon as it is connected to the network.
11.3.2 Communication with Host Name
First, if you run the “ping” command on the Raspberry Pi system, you can get the result as follows.
pi@raspberrypi ~ $ ping raspberrypi
PING raspberrypi (127.0.1.1) 56(84) bytes of data.
64 bytes from raspberrypi (127.0.1.1): icmp_req=1 ttl=64 time=0.182 ms
64 bytes from raspberrypi (127.0.1.1): icmp_req=2 ttl=64 time=0.183 ms
64 bytes from raspberrypi (127.0.1.1): icmp_req=3 ttl=64 time=0.189 ms
64 bytes from raspberrypi (127.0.1.1): icmp_req=4 ttl=64 time=0.208 ms
64 bytes from raspberrypi (127.0.1.1): icmp_req=5 ttl=64 time=0.186 ms
64 bytes from raspberrypi (127.0.1.1): icmp_req=6 ttl=64 time=0.233 ms
11.3 Using Host Name
11.3.1 Setting Host Name
In the Raspberry Pi system, the name of the system itself is called host name. This host name has the function of refering to the Raspberry Pi system itself in the local network. Therefore, when another system in the same network communicates with the Raspberry Pi system, the host name can be used instead of the IP address assigned to the Raspberry Pi system.