RK3568 Ubuntu 20.044G模块 USB Wi-Fi 热点完整操作步骤适用硬件移远 EC200NUSB ID2c7c:6002和 Realtek USB Wi-Fi初始 ID0bda:1a2b切换后 ID0bda:c820。以下命令均在 RK3568板卡上以root用户执行。开发板使用鲁班猫21. 连接硬件并进入 root 终端断开板卡电源。插入 4G 模块、SIM 卡和 4G 天线。插入 Realtek USB Wi-Fi 和 Wi-Fi 天线。给板卡上电通过串口、显示器键盘或已有网络登录系统。切换到rootsudo-i确认系统uname-acat/etc/os-release2. 临时连接互联网并安装软件首次安装软件时先通过板载网口或其他临时网络让板卡能够访问互联网。ping-c4223.5.5.5安装所需软件apt-getupdateapt-getinstall-y\network-manager modemmanager ppp\usb-modeswitch usb-modeswitch-data\dnsmasq-base iw iptables\usbutils atinoutcurl启用服务systemctlenable--nowNetworkManager systemctlenable--nowModemManager systemctl is-active NetworkManager systemctl is-active ModemManager两项均应返回active3. 检查 4G 模块lsusbls-l/dev/ttyUSB*2/dev/null mmcli-L应看到类似结果ID 2c7c:6002 Quectel Wireless Solutions Co., Ltd. /dev/ttyUSB0 /dev/ttyUSB1 /dev/ttyUSB2 /org/freedesktop/ModemManager1/Modem/0 [Quectel] EC200N查看模块状态mmcli-m0确认 SIM 卡已识别模块状态不是failed或locked。4. 创建中国电信 4G 拨号配置确认不存在同名配置nmcli connection show lubancat-4g-gsm2/dev/null||true如果不存在创建配置nmcli connectionadd\typegsm\ifname*\con-name lubancat-4g-gsm\apn ctnet设置自动拨号、路由优先级和 DNSnmcli connection modify lubancat-4g-gsm\connection.autoconnectyes\connection.autoconnect-priority50\ipv4.method auto\ipv4.route-metric20\ipv4.ignore-auto-dnsyes\ipv4.dns223.5.5.5,114.114.114.114\ipv6.method ignore启动拨号nmcli connection up lubancat-4g-gsm等待 10 秒后检查sleep10nmcli-fDEVICE,TYPE,STATE,CONNECTION deviceip-braddr show ppp0iprouteiproute get1.1.1.1应看到ttyUSB2 gsm connected lubancat-4g-gsm default dev ppp0 ... metric 20 1.1.1.1 dev ppp0 ...测试 4G 网络ping-c4223.5.5.5 getent ahostsv4 www.baidu.comcurl-4--max-time15-Ihttps://www.baidu.com/5. 确保 ECM 接口不抢占 4G 默认路由检查是否存在usb1的活动连接nmcli-fNAME,DEVICE,TYPE,AUTOCONNECT connection showiproute如果某个活动连接的DEVICE是usb1记录它的连接名称然后执行nmcli connection modify这里替换为usb1连接名称connection.autoconnect no nmcli connection down这里替换为usb1连接名称例如连接名称为Wired connection 2nmcli connection modifyWired connection 2connection.autoconnect no nmcli connection downWired connection 2部分系统上usb1由外部 DHCP 程序管理ip route能看到usb1路由但nmcli中没有DEVICE为usb1的活动连接。这种情况不要猜测连接名称或强制关闭 USB 网卡而是检查实际选路结果。再次确认访问公网时使用ppp0iprouteiproute get1.1.1.1ip route get 1.1.1.1必须显示dev ppp0。只要 PPP 默认路由的metric 为 20、ECM 备用路由的 metric 更大例如 100即使ip route中保留了usb1默认路由它也不会抢占 4G PPP 流量。6. 将 USB Wi-Fi 从驱动盘模式切换为网卡模式查看当前 USB IDlsusb|grep-Ei0bda:1a2b|0bda:c820如果显示0bda:1a2b执行usb_modeswitch-KW-v0bda-p1a2bsleep4检查切换结果lsusb|grep-Ei0bda:1a2b|0bda:c820应看到ID 0bda:c820 Realtek Semiconductor Corp.7. 加载 Wi-Fi 驱动并确认 AP 能力modprobe 8821cu lsmod|grep8821cuip-brlinkiw dev应出现接口wlan0确认驱动支持 APiw list|sed-n/Supported interface modes:/,/Band /p输出中必须包含* AP如果modprobe 8821cu报错检查当前系统是否包含驱动find/lib/modules/$(uname-r)-name*8821cu*.ko*找到驱动后执行depmod-amodprobe 8821cu8. 配置 USB Wi-Fi 开机自动切换创建 systemd 服务tee/etc/systemd/system/realtek-usb-wifi-switch.service/dev/nullEOF [Unit] DescriptionSwitch Realtek USB Wi-Fi from DISK to WLAN mode Aftersystemd-udev-trigger.service [Service] Typeoneshot ExecStart/bin/sh -c for i in $(seq 1 20); do if /usr/bin/lsusb -d 0bda:c820 | /bin/grep -q .; then exit 0; fi; if /usr/bin/lsusb -d 0bda:1a2b | /bin/grep -q .; then /usr/sbin/usb_modeswitch -KW -v 0bda -p 1a2b; exit 0; fi; /bin/sleep 1; done; exit 0 [Install] WantedBymulti-user.target EOF启用服务systemctl daemon-reload systemctlenable--nowrealtek-usb-wifi-switch.service systemctl is-enabled realtek-usb-wifi-switch.service应返回enabled9. 创建 Wi-Fi 热点下面使用以下热点参数SSIDRK3568-4G 密码rk3568wifi 板卡热点地址10.42.0.1正式使用时请把密码rk3568wifi替换为至少 8 位的新密码。确认不存在同名配置nmcli connection show rk3568-4g-hotspot2/dev/null||true如果不存在创建热点nmcli connectionadd\typewifi\ifname wlan0\con-name rk3568-4g-hotspot\autoconnectyes\ssid RK3568-4G设置 AP、密码和共享网络nmcli connection modify rk3568-4g-hotspot\802-11-wireless.mode ap\802-11-wireless.bandbg\802-11-wireless.channel6\wifi-sec.key-mgmt wpa-psk\wifi-sec.pskrk3568wifi\ipv4.method shared\ipv4.addresses10.42.0.1/24\ipv6.method ignore\connection.autoconnectyes\connection.autoconnect-priority100启动热点nmcli connection up rk3568-4g-hotspot10. 检查热点、DHCP、DNS 和 NATnmcli-fDEVICE,TYPE,STATE,CONNECTION deviceip-braddr show wlan0 iw dev wlan0 infocat/proc/sys/net/ipv4/ip_forward ss-lunp|grep-E10.42.0.1:53|0.0.0.0:67iptables-tnat-S|grep10.42.0.0/24应满足wlan0 connected rk3568-4g-hotspot wlan0 地址为 10.42.0.1/24 iw 显示 type AP 和 ssid RK3568-4G ip_forward 为 1 存在 UDP 53、UDP 67 和 MASQUERADE 规则11. 用手机或电脑连接热点测试上网在手机或电脑上搜索 Wi-Fi。连接热点RK3568-4G。输入密码rk3568wifi。确认客户端获得10.42.0.x地址。确认网关和 DNS 为10.42.0.1。打开网页测试上网。在板卡上查看已连接客户端cat/var/lib/NetworkManager/dnsmasq-wlan0.leases iw dev wlan0 station dump连接热点后可从客户端登录板卡sshroot10.42.0.112. 重启并验证自动恢复reboot等待板卡启动完成在手机或电脑上重新连接RK3568-4G然后登录板卡sshroot10.42.0.1板卡刚能 SSH 登录时ModemManager 可能仍在等待 4G 模块注册ttyUSB2和wlan0短暂显示未连接属于正常启动过程。建议等待30 秒后再执行完整检查sleep30执行完整检查lsusb|grep-E2c7c:6002|0bda:c820|0bda:1a2bsystemctl is-active NetworkManager ModemManager systemctl is-enabled realtek-usb-wifi-switch.service nmcli-fDEVICE,TYPE,STATE,CONNECTION deviceip-braddriprouteiproute get1.1.1.1 iw dev wlan0 infocat/proc/sys/net/ipv4/ip_forward iptables-tnat-S|grepMASQUERADEping-c4www.baidu.com最终应达到4G 模块2c7c:6002 4G 拨号ttyUSB2 / ppp0 / connected 公网有效路由ppp0metric 20以 ip route get 1.1.1.1 为准 USB Wi-Fi0bda:c820 热点wlan0 / RK3568-4G / 10.42.0.1/24 客户端能够获得 10.42.0.x 地址并访问互联网13. 连接失败时按顺序恢复重新启动 4G 拨号nmcli connection down lubancat-4g-gsm nmcli connection up lubancat-4g-gsmsleep10iproute get1.1.1.1ping-c4223.5.5.5重新切换并加载 USB Wi-Fiusb_modeswitch-KW-v0bda-p1a2b||truesleep4modprobe 8821cuip-brlinkshow wlan0重新启动热点nmcli connection down rk3568-4g-hotspot nmcli connection up rk3568-4g-hotspot重新启动网络服务systemctl restart ModemManager systemctl restart NetworkManagersleep10nmcli connection up lubancat-4g-gsm nmcli connection up rk3568-4g-hotspot再次检查nmcli-fDEVICE,TYPE,STATE,CONNECTION deviceiproute iw dev wlan0 info journalctl-uNetworkManager-b--no-pager|tail-n100journalctl-uModemManager-b--no-pager|tail-n100
