Raspberry Pi uses a USB wireless adapter

The wireless adapter must be supported by Raspberry Pi. You can go to the official or http://shumeipai.net to view the hardware list

Either of the two solutions can not be changed

# Solution 1

# Configure network interfaces

Sudo nano/etc/Network/interfaces

The default file content is as follows:

Auto Lo

Iface lo Inet loopback
Iface eth0 Inet DHCP

Allow-hotplug wlan0
Iface wlan0 Inet Manual
WPA-roam/etc/wpa_supplicant/wpa_supplicant.conf
Iface default Inet DHCP

Modify as follows:
DHCP Configuration:

Auto Lo

Iface lo Inet loopback
Iface eth0 Inet DHCP

Allow-hotplug wlan0
Auto wlan0
Iface wlan0 Inet DHCP
WPA-roam/etc/wpa_supplicant/wpa_supplicant.conf

Static Configuration:

Auto Lo

Iface lo Inet loopback
Iface eth0 Inet DHCP

Allow-hotplug wlan0
Iface wlan0 Inet Manual
Address 192.168.0.100
Netmask 255.255.255.0
Gateway 192.168.0.1
WPA-roam/etc/wpa_supplicant/wpa_supplicant.conf

# Set WPA Authentication

Sudo nano/etc/wpa_supplicant/wpa_supplicant.conf

Modify as follows:

Network = {
SSID = "SSID name"
PROTO = RSN
Key_mgmt = WPA-PSK
Pairwise = CCMP TKIP
Group = CCMP TKIP
PSK = "password"
}

# Restart. wlan0 is automatically enabled.

# Solution 2

# WPA authentication File

Sudo nano/etc/wpa_supplicant/wpa_supplicant.conf

The modified content is as follows:

Ctrl_interface = dir =/var/run/wpa_supplicant group = netdev
Update_config = 1

Network = {
SSID = "SSID name"
PROTO = RSN
Scan_ssid = 1
Key_mgmt = WPA-PSK
Pairwise = CCMP
Auth_alg = open
PSK = "password"
}

# Modify the interfaces Configuration

Sudo nano/etc/Network/interfaces

DHCP Configuration:

Auto Lo

Iface lo Inet loopback
Iface eth0 Inet DHCP

Allow-hotplug wlan0
Auto wlan0
Iface wlan0 Inet Manual
WPA-roam/etc/wpa_supplicant/wpa_supplicant.conf
Iface default Inet DHCP

Static Configuration:

Auto Lo

Iface lo Inet loopback
Iface eth0 Inet DHCP

Allow-hotplug wlan0
Iface wlan0 Inet Manual
Address 192.168.0.100
Netmask 255.255.255.0
Gateway 192.168.0.1
WPA-roam/etc/wpa_supplicant/wpa_supplicant.conf
Iface default Inet DHCP

# Restart

By default, it will be automatically connected. You can run 'sudo iwconfig' to view the configuration or 'sudo ifconfig' to view the status.