上週在 Pi Zero W 上順利安裝了 Raspbian Buster, 因為此板內建 WiFi, 因此初次開機設定重啟後, 按右上角的無線連線 wlan0 即可選擇無線基地台. 但今天拿出去年買來卻一直未開機測試的 Pi 3A+, 燒錄同樣的 Buster 映像檔重開機後, 點右上角的無線連線 icon 卻顯示 "no wireless interface found", 無線網卡沒起來, 根本無法選擇基地台.
開啟終端機, 用 ifconfig 查詢網路介面, 只有 loopback (lo) 而已, 沒有 wlan0 :
pi@raspberrypi:~ $
ifconfig
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 9 bytes 524 (524.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 9 bytes 524 (524.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
花了一整晚研究這問題, 測試了網上各種解決辦法都沒有效, 奇怪, Buster 在 Pi Zero W 上沒問題, 難道這是 P3 A+ 板子的問題? 我找到下面這篇台灣樹莓派論壇的教學文章, 說 2018 年新版 Raspbian 作業系統的無線網路設定檔 /etc/wpa_supplicant/wpa_supplicant.conf 中拿掉了 WiFi 的國家設定 :
#
[教學] 啟用 Pi 3B+的WiFi
我檢視此檔原始內容只有兩行 :
pi@raspberrypi:~ $
sudo cat /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
進入桌面系統的 "偏好設定/Raaspberry Pi 設定" :
切到最右邊 "在地化", 按 "設定 WiFi 國家", 在下拉式選單中選擇國家為台灣, 按確定即可 :
也可以在終端機下 sudo raspi-config 去設定 :
pi@raspberrypi:~ $
sudo raspi-config
選 "Localization Options" :
選 "Change WiFi Country" :
選擇 "TW Taiwan" 按確定即可 :
再次檢查 /etc/wpa_supplicant/wpa_supplicant.conf 就會出現國家設定了 :
pi@raspberrypi:~ $
sudo cat /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=TW
然後還要去修改網路介面設定檔 /etc/network/interfaces, 加入 wlan0 設定, 其原始內容為 :
pi@raspberrypi:~ $
sudo cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
要加上如下內容 :
allow-hotplug wlan0
auto wlan0
iface wlan0 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
pi@raspberrypi:~ $
sudo nano /etc/network/interfaces
pi@raspberrypi:~ $
sudo cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
allow-hotplug wlan0
auto wlan0
iface wlan0 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
pi@raspberrypi:~ $
sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
pi@raspberrypi:~ $
sudo cat /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=TW
network={
ssid="TonyNote8"
psk="123456"
}
參考 :
#
[教學] 啟用 Pi 3B+的WiFi
#
RPI 3 B+ No wireless interfaces found
#
Raspberry Pi 的基礎 - 使用 Wi-Fi 無線網卡連上網路
#
Raspberry Pi Wi-Fi & Bluetooth Setup - How to Configure your Pi 4 Model B, 3 Model B and 3 Model B+ Connectivity
