Up Raspberry Pi 側の設定 作成: 2021-10-04
更新: 2021-10-05

  1. WiFi サーバ (アクセスポイント化) ソフト hostapd のインストール
      $ sudo apt update

      $ sudo apt install libssl-dev libdbus-1-dev libnl-3-dev libnl-genl-3-dev libnl-route-3-dev Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt --fix-broken install' to correct these. The following packages have unmet dependencies: avrdude : Depends: libncurses5 (>= 5.5-5~) but it is not going to be installed libssl-dev : Depends: libssl1.1 (= 1.1.1d-0+deb10u7) but 1.1.1d-0+deb10u6+rpt1 is to be installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution). 　(インストール失敗)
      "Try 'apt --fix-broken install' " に従う：
      $ sudo apt --fix-broken install Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following additional packages will be installed: libncurses5 The following NEW packages will be installed: libncurses5 0 upgraded, 1 newly installed, 0 to remove and 211 not upgraded. 1 not fully installed or removed. Need to get 75.3 kB of archives. After this operation, 238 kB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://ftp.jaist.ac.jp/pub/Linux/raspbian-archive/raspbian buster/main armhf libncurses5 armhf 6.1+20181013-2+deb10u2 [75.3 kB] Fetched 75.3 kB in 1s (64.6 kB/s) Selecting previously unselected package libncurses5:armhf. (Reading database ... 172959 files and directories currently installed.) Preparing to unpack .../libncurses5_6.1+20181013-2+deb10u2_armhf.deb ... Unpacking libncurses5:armhf (6.1+20181013-2+deb10u2) ... Setting up libncurses5:armhf (6.1+20181013-2+deb10u2) ... Setting up avrdude (1:5.10-4) ... Processing triggers for libc-bin (2.28-10+rpi1) ...
      $ sudo apt install libssl-dev libdbus-1-dev libnl-3-dev libnl-genl-3-dev libnl-route-3-dev
      （インストール成功）

      $ sudo apt install hostapd Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed: hostapd 0 upgraded, 1 newly installed, 0 to remove and 209 not upgraded. Need to get 632 kB of archives. After this operation, 1,729 kB of additional disk space will be used. Get:1 http://ftp.jaist.ac.jp/pub/Linux/raspbian-archive/raspbian buster/main armhf hostapd armhf 2:2.7+git20190128+0c1e29f-6+deb10u3 [632 kB] Fetched 632 kB in 2s (359 kB/s) Selecting previously unselected package hostapd. (Reading database ... 173164 files and directories currently installed.) Preparing to unpack .../hostapd_2%3a2.7+git20190128+0c1e29f-6+deb10u3_armhf.deb ... Unpacking hostapd (2:2.7+git20190128+0c1e29f-6+deb10u3) ... Setting up hostapd (2:2.7+git20190128+0c1e29f-6+deb10u3) ... Created symlink /etc/systemd/system/multi-user.target.wants/hostapd.service → /lib/systemd/system/hostapd.service. Job for hostapd.service failed because the control process exited with error code. See "systemctl status hostapd.service" and "journalctl -xe" for details. Created symlink /etc/systemd/system/hostapd.service → /dev/null. Processing triggers for man-db (2.8.5-2) ... Processing triggers for systemd (241-7~deb10u6+rpi1) ... hostapd は，/usr/sbin に置かれる


  2. hostapd の設定ファイル /etc/hostapd/hostapd.conf を作成
      $ cd /etc/hostapd
      $ sudo vi hostapd.conf
        interface=wlan0
        country_code=JP
        driver=nl80211
        hw_mode=g
        ieee80211d=1
        channel=6
        auth_algs=1
        ignore_broadcast_ssid=0
        disassoc_low_ack=1
        ieee80211n=1
        ht_capab=[HT40] [SHORT-GI-20] [DSSS_CCK-40]
        require_ht=0
        rsn_pairwise=CCMP
        max_num_sta=3
        ssid=raspi
        wpa_passphrase=12345678
        wpa=2
        wpa_key_mgmt=WPA-PSK
        wpa_group_rekey=86400

      ssid, wpa_passphrase は任意。
      但し，wpa_passphrase には「不適切」がある。
      つぎは，６文字の passphrase を設定したときの，hostapd 起動エラーメッセージ：
        Configuration file: /etc/hostapd/hostapd.conf Line 16: invalid WPA passphrase length 6 (expected 8..63) WPA-PSK enabled, but PSK or passphrase is not configured. 2 errors found in configuration file '/etc/hostapd/hostapd.conf' Failed to set up interface with /etc/hostapd/hostapd.conf Failed to initialize interface


  3. WiFi クライアント用の wpa_supplicant を無効にする
      $ cd /etc/wpa_supplicant
      $ sudo mv wpa_supplicant.conf wpa_supplicant.conf_org

      $ sudo systemctl disable wpa_supplicant Removed /etc/systemd/system/dbus-fi.w1.wpa_supplicant1.service. Removed /etc/systemd/system/multi-user.target.wants/wpa_supplicant.service.
      $ sudo reboot

      wpa_supplicant が無くなっていることを確認：
      $ ps aux | grep wpa


  4. wlan0 に固定IPアドレスを設定する
      ( /etc/network/interfaces.d/wlan0 を作成する)
      $ cd /etc/network/interfaces.d
      $ sudo vi wlan0
        allow-hotplug wlan0
        iface wlan0 inet static
        address 10.10.10.1
        netmask 255.255.255.0


  5. hostapd の起動テスト
      $ sudo hostapd /etc/hostapd/hostapd.conf
      Configuration file: /etc/hostapd/hostapd.conf rfkill: WLAN soft blocked wlan0: interface state UNINITIALIZED->COUNTRY_UPDATE wlan0: INTERFACE-DISABLED wlan0: Could not connect to kernel driver Using interface wlan0 with hwaddr b8:27:eb:1c:15:60 and ssid "raspi" Failed to set beacon parameters wlan0: Could not connect to kernel driver Interface initialization failed wlan0: interface state COUNTRY_UPDATE->DISABLED wlan0: AP-DISABLED wlan0: interface state DISABLED->DISABLED wlan0: AP-DISABLED wlan0: CTRL-EVENT-TERMINATING hostapd_free_hapd_data: Interface wlan0 wasn't started nl80211: deinit ifname=wlan0 disabled_11b_rates=0 （"rfkill: WLAN soft blocked" による起動失敗らしい）

      $ rfkill list 0: phy0: Wireless LAN Soft blocked: yes Hard blocked: no $ sudo rfkill unblock wifi
      $ rfkill list 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no
      $ sudo hostapd /etc/hostapd/hostapd.conf
      wlan0: interface state UNINITIALIZED->COUNTRY_UPDATE wlan0: Could not connect to kernel driver Using interface wlan0 with hwaddr b8:27:eb:1c:15:60 and ssid "raspi" wlan0: interface state COUNTRY_UPDATE->ENABLED wlan0: AP-ENABLED （起動成功）


  6. WiFi で IP通信するときの Raspberry Pi の IPアドレスを設定する
    　── /etc/dhcpcd.conf の編集
      PC からターミナルの新規ウィンドウで，ssh 接続
      $ cd /etc
      $ sudo cp dhcpcd.conf dhcpcd.conf_org
      $ sudo vi dhcpcd.conf 　‥‥‥ interface wlan0 static ip_address=10.10.10.1
      $ sudo cp dhcpcd.conf dhcpcd.conf_p2p_wifi

  7. 再起動 ( /etc/dhcpcd.conf の設定を有効にする)
      $ sudo reboot


  8. hostapd を起動
      $ sudo hostapd /etc/hostapd/hostapd.conf