树莓派无线网在串口下配置，不需要显示器，RTL8192CU的USB网卡芯片

【===================先展示一下最后的效果=======================】

树莓派插入网卡，有供电，有TF卡。就可以了



打开终端：直接登录上去，可以看到，当有数据传输时，小灯闪爆你的钛合金眼



【=======================效果展示完毕===============】

【2016淘宝热销树莓派无线网卡】

无线网卡 EDUP EP-N8508GS 芯片:RTL8188CUS 带宽150bps

开始干活！
为什么用300M带宽的无线网卡？
怎么为树莓派安装新的系统？
为什么是串口，而不是双绞线
怎么接线？
怎么安装串口驱动？
怎么设置终端
怎么登陆树莓派
要不要安装无线网卡驱动？
开始干活：扫描AP热点
两种连接无线网的方式！
显示连接的wifi状态

【我手头上只有2012年前买的这个网卡】
无线网卡 水星MW300U 芯片:RTL8192CU 带宽300M



整个过程，没有拿RJ45双绞线。因为路由器距离我2米多远，懒得拿网线把树莓派接到路由器。
但是PC距离我很近，索性用串口干活，同时还避免了配置无线的时候有线网络带来的干扰，在Linux下干活的人会知道IP的绑定和内核有关系，具体IP在哪个网卡设备工作，是另外一回儿事儿。
下载树莓派系统
写到内存卡
不做任何修改，上机，先不插入网卡。

串口线接好【图】



PC端串口驱动装好，我的USB转串口，芯片是CH340，
CH340驱动点击下载
解压打开目录：USB to UART Driver/CH340_CH341双击安装
插入CH340，在设备管理器会发现有了一个COM号





终端设置好，直接用串口干活 ，设置波特率：115200



开机信息输出：

Uncompressing Linux... done, booting the kernel.
[    0.000000] Booting Linux on physical CPU 0xf00
[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Initializing cgroup subsys cpuacct
[    0.000000] Linux version 4.4.11-v7+ (dc4@dc4-XPS13-9333) (gcc version 4.9.3 (crosstool-NG crosstool-ng-1.22.0-88-g8460611) ) #888 SMP Mon May 23 20:10:33 BST 2016
[    0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c5387d
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] Machine model: Raspberry Pi 2 Model B Rev 1.1
[    0.000000] cma: Reserved 8 MiB at 0x36800000
[    0.000000] Memory policy: Data cache writealloc
[    0.000000] [bcm2709_smp_init_cpus] enter (9520->f3003010)
[    0.000000] [bcm2709_smp_init_cpus] ncores=4
[    0.000000] PERCPU: Embedded 13 pages/cpu @b5ff3000 s22592 r8192 d22464 u53248
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 223300
[    0.000000] Kernel command line: dma.dmachans=0x7f35 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416 bcm2709.boardrev=0xa21041 bcm2709.serial=0xf4c5cc4 smsc95xx.macaddr=B8:27:EB:4C:5C:C4 bcm2708_fb.fbswap=1 bcm2709.uart_clock=3000000 bcm2709.disk_led_gpio=47 bcm2709.disk_led_active_low=0 vc_mem.mem_base=0x3dc00000 vc_mem.mem_size=0x3f000000  dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
[    0.000000] PID hash table entries: 4096 (order: 2, 16384 bytes)
[    0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
[    0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.000000] Memory: 874128K/901120K available (6344K kernel code, 432K rwdata, 1712K rodata, 476K init, 764K bss, 18800K reserved, 8192K cma-reserved)
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
[    0.000000]     vmalloc : 0xb7800000 - 0xff800000   (1152 MB)
[    0.000000]     lowmem  : 0x80000000 - 0xb7000000   ( 880 MB)
[    0.000000]     modules : 0x7f000000 - 0x80000000   (  16 MB)
[    0.000000]       .text : 0x80008000 - 0x807e6420   (8058 kB)
[    0.000000]       .init : 0x807e7000 - 0x8085e000   ( 476 kB)
[    0.000000]       .data : 0x8085e000 - 0x808ca0c8   ( 433 kB)
[    0.000000]        .bss : 0x808cd000 - 0x8098c1ac   ( 765 kB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] Hierarchical RCU implementation.
[    0.000000]     Build-time adjustment of leaf fanout to 32.
[    0.000000] NR_IRQS:16 nr_irqs:16 16
[    0.000000] Architected cp15 timer(s) running at 19.20MHz (phys).
[    0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x46d987e47, max_idle_ns: 440795202767 ns
[    0.000011] sched_clock: 56 bits at 19MHz, resolution 52ns, wraps every 4398046511078ns
[    0.000031] Switching to timer-based delay loop, resolution 52ns
[    0.000353] Console: colour dummy device 80x30
[    0.001602] console [tty1] enabled
[    0.001654] Calibrating delay loop (skipped), value calculated using timer frequency.. 38.40 BogoMIPS (lpj=192000)
[    0.001732] pid_max: default: 32768 minimum: 301
[    0.002149] Mount-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.002199] Mountpoint-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.003417] Disabling cpuset control group subsystem
[    0.003499] Initializing cgroup subsys io
[    0.003559] Initializing cgroup subsys memory
[    0.003639] Initializing cgroup subsys devices
[    0.003691] Initializing cgroup subsys freezer
[    0.003742] Initializing cgroup subsys net_cls
[    0.003841] CPU: Testing write buffer coherency: ok
[    0.003952] ftrace: allocating 21205 entries in 63 pages
[    0.056251] CPU0: update cpu_capacity 1024
[    0.056329] CPU0: thread -1, cpu 0, socket 15, mpidr 80000f00
[    0.056367] [bcm2709_smp_prepare_cpus] enter
[    0.056521] Setting up static identity map for 0x8240 - 0x8274
[    0.058900] [bcm2709_boot_secondary] cpu:1 started (0) 17
[    0.059335] [bcm2709_secondary_init] enter cpu:1
[    0.059396] CPU1: update cpu_capacity 1024
[    0.059404] CPU1: thread -1, cpu 1, socket 15, mpidr 80000f01
[    0.059977] [bcm2709_boot_secondary] cpu:2 started (0) 17
[    0.060329] [bcm2709_secondary_init] enter cpu:2
[    0.060360] CPU2: update cpu_capacity 1024
[    0.060367] CPU2: thread -1, cpu 2, socket 15, mpidr 80000f02
[    0.060915] [bcm2709_boot_secondary] cpu:3 started (0) 16
[    0.061169] [bcm2709_secondary_init] enter cpu:3
[    0.061200] CPU3: update cpu_capacity 1024
[    0.061208] CPU3: thread -1, cpu 3, socket 15, mpidr 80000f03
[    0.061293] Brought up 4 CPUs
[    0.061405] SMP: Total of 4 processors activated (153.60 BogoMIPS).
[    0.061438] CPU: All CPU(s) started in HYP mode.
[    0.061467] CPU: Virtualization extensions available.
[    0.062391] devtmpfs: initialized
[    0.074851] VFP support v0.3: implementor 41 architecture 2 part 30 variant 7 rev 5
[    0.075352] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.076442] pinctrl core: initialized pinctrl subsystem
[    0.077261] NET: Registered protocol family 16
[    0.083074] DMA: preallocated 4096 KiB pool for atomic coherent allocations
[    0.091266] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
[    0.091330] hw-breakpoint: maximum watchpoint size is 8 bytes.
[    0.091556] Serial: AMBA PL011 UART driver
[    0.091907] 3f201000.uart: ttyAMA0 at MMIO 0x3f201000 (irq = 87, base_baud = 0) is a PL011 rev2
[    0.594608] console [ttyAMA0] enabled
[    0.598904] bcm2835-mbox 3f00b880.mailbox: mailbox enabled
[    0.676443] bcm2835-dma 3f007000.dma: DMA legacy API manager at f3007000, dmachans=0x1
[    0.686523] SCSI subsystem initialized
[    0.690533] usbcore: registered new interface driver usbfs
[    0.696177] usbcore: registered new interface driver hub
[    0.701654] usbcore: registered new device driver usb
[    0.716826] raspberrypi-firmware soc:firmware: Attached to firmware from 2016-05-20 19:05
[    0.752623] clocksource: Switched to clocksource arch_sys_counter
[    0.811814] FS-Cache: Loaded
[    0.815188] CacheFiles: Loaded
[    0.834716] NET: Registered protocol family 2
[    0.840334] TCP established hash table entries: 8192 (order: 3, 32768 bytes)
[    0.847600] TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
[    0.854268] TCP: Hash tables configured (established 8192 bind 8192)
[    0.860785] UDP hash table entries: 512 (order: 2, 16384 bytes)
[    0.866804] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[    0.873530] NET: Registered protocol family 1
[    0.878375] RPC: Registered named UNIX socket transport module.
[    0.884363] RPC: Registered udp transport module.
[    0.889083] RPC: Registered tcp transport module.
[    0.893819] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    0.901677] hw perfevents: enabled with armv7_cortex_a7 PMU driver, 5 counters available
[    0.911606] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    0.933580] VFS: Disk quotas dquot_6.6.0
[    0.937896] VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    0.947749] FS-Cache: Netfs 'nfs' registered for caching
[    0.954277] NFS: Registering the id_resolver key type
[    0.959404] Key type id_resolver registered
[    0.963636] Key type id_legacy registered
[    0.970770] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 252)
[    0.978432] io scheduler noop registered
[    0.982385] io scheduler deadline registered (default)
[    0.987641] io scheduler cfq registered
[    0.994464] BCM2708FB: allocated DMA memory f6c00000
[    0.999485] BCM2708FB: allocated DMA channel 0 @ f3007000
[    1.010750] Console: switching to colour frame buffer device 82x26
[    1.965819] bcm2835-rng 3f104000.rng: hwrng registered
[    1.972804] vc-cma: Videocore CMA driver
[    1.978377] vc-cma: vc_cma_base      = 0x00000000
[    1.984763] vc-cma: vc_cma_size      = 0x00000000 (0 MiB)
[    1.991743] vc-cma: vc_cma_initial   = 0x00000000 (0 MiB)
[    1.998975] vc-mem: phys_addr:0x00000000 mem_base=0x3dc00000 mem_size:0x3f000000(1008 MiB)
[    2.030793] brd: module loaded
[    2.046589] loop: module loaded
[    2.052279] vchiq: vchiq_init_state: slot_zero = 0xb6c80000, is_master = 0
[    2.062425] Loading iSCSI transport class v2.0-870.
[    2.069728] usbcore: registered new interface driver smsc95xx
[    2.077096] dwc_otg: version 3.00a 10-AUG-2012 (platform bus)
[    2.284749] Core Release: 2.80a
[    2.289329] Setting default values for core params
[    2.295641] Finished setting default values for core params
[    2.503152] Using Buffer DMA mode
[    2.507941] Periodic Transfer Interrupt Enhancement - disabled
[    2.515312] Multiprocessor Interrupt Enhancement - disabled
[    2.522435] OTG VER PARAM: 0, OTG VER FLAG: 0
[    2.528348] Dedicated Tx FIFOs mode
[    2.533758] WARN::dwc_otg_hcd_init:1047: FIQ DMA bounce buffers: virt = 0xb6c14000 dma = 0xf6c14000 len=9024
[    2.546785] FIQ FSM acceleration enabled for :
[    2.546785] Non-periodic Split Transactions
[    2.546785] Periodic Split Transactions
[    2.546785] High-Speed Isochronous Endpoints
[    2.546785] Interrupt/Control Split Transaction hack enabled
[    2.577172] WARN::hcd_init_fiq:413: FIQ on core 1 at 0x804464e4
[    2.584729] WARN::hcd_init_fiq:414: FIQ ASM at 0x80446854 length 36
[    2.592589] WARN::hcd_init_fiq:439: MPHI regs_base at 0xb787e000
[    2.600213] dwc_otg 3f980000.usb: DWC OTG Controller
[    2.606788] dwc_otg 3f980000.usb: new USB bus registered, assigned bus number 1
[    2.615730] dwc_otg 3f980000.usb: irq 62, io mem 0x00000000
[    2.622911] Init: Port Power? op_state=1
[    2.628359] Init: Power Port (0)
[    2.633371] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[    2.641721] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    2.650518] usb usb1: Product: DWC OTG Controller
[    2.656767] usb usb1: Manufacturer: Linux 4.4.11-v7+ dwc_otg_hcd
[    2.664325] usb usb1: SerialNumber: 3f980000.usb
[    2.671477] hub 1-0:1.0: USB hub found
[    2.676784] hub 1-0:1.0: 1 port detected
[    2.683351] usbcore: registered new interface driver usb-storage
[    2.691179] mousedev: PS/2 mouse device common for all mice
[    2.699067] bcm2835-cpufreq: min=600000 max=900000
[    2.705742] sdhci: Secure Digital Host Controller Interface driver
[    2.713478] sdhci: Copyright(c) Pierre Ossman
[    2.719721] sdhost: log_buf @ b6c13000 (f6c13000)
[    2.802674] mmc0: sdhost-bcm2835 loaded - DMA enabled (>1)
[    2.810025] sdhci-pltfm: SDHCI platform and OF driver helper
[    2.838212] ledtrig-cpu: registered to indicate activity on CPUs
[    2.846032] hidraw: raw HID events driver (C) Jiri Kosina
[    2.853247] usbcore: registered new interface driver usbhid
[    2.860366] usbhid: USB HID core driver
[    2.866411] Initializing XFRM netlink socket
[    2.872284] NET: Registered protocol family 17
[    2.876573] mmc0: command never completed.
[    2.876588] mmc0:>cmd op 5 arg 0x0 flags 0x2e1 - resp 00000000 00000000 00000000 00000000, err 0
[    2.876593] mmc0: =========== REGISTER DUMP ===========
[    2.876598] mmc0: SDCMD  0x00004005
[    2.876601] mmc0: SDARG  0x00000000
[    2.876605] mmc0: SDTOUT 0x00030d40
[    2.876610] mmc0: SDCDIV 0x0000026f
[    2.876614] mmc0: SDRSP0 0xffffffff
[    2.876618] mmc0: SDRSP1 0x0000ff7f
[    2.876622] mmc0: SDRSP2 0xc2000000
[    2.876626] mmc0: SDRSP3 0xffffffff
[    2.876630] mmc0: SDHSTS 0x00000040
[    2.876634] mmc0: SDVDD  0x00000001
[    2.876638] mmc0: SDEDM  0x00010800
[    2.876642] mmc0: SDHCFG 0x0000040a
[    2.876645] mmc0: SDHBCT 0x00000000
[    2.876650] mmc0: SDHBLC 0x00000000
[    2.876653] mmc0: ===========================================
[    2.922566] mmc0: host does not support reading read-only switch, assuming write-enable
[    2.941821] mmc0: new high speed SDHC card at address 0002
[    2.942652] mmcblk0: mmc0:0002 00000 15.0 GiB
[    2.964681]  mmcblk0: p1 p2
[    3.001313] Indeed it is in host mode hprt0 = 00021501
[    3.001389] Key type dns_resolver registered
[    3.001973] Registering SWP/SWPB emulation handler
[    3.003201] registered taskstats version 1
[    3.003497] vc-sm: Videocore shared memory driver
[    3.003510] [vc_sm_connected_init]: start
[    3.007969] [vc_sm_connected_init]: end - returning 0
[    3.008230] of_cfs_init
[    3.008361] of_cfs_init: OK
[    3.062950] EXT4-fs (mmcblk0p2): INFO: recovery required on readonly filesystem
[    3.071598] EXT4-fs (mmcblk0p2): write access will be enabled during recovery
[    3.222684] usb 1-1: new high-speed USB device number 2 using dwc_otg
[    3.230759] Indeed it is in host mode hprt0 = 00001101
[    3.442993] usb 1-1: New USB device found, idVendor=0424, idProduct=9514
[    3.451304] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    3.461139] hub 1-1:1.0: USB hub found
[    3.466600] hub 1-1:1.0: 5 ports detected
[    3.752663] usb 1-1.1: new high-speed USB device number 3 using dwc_otg
[    3.872934] usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00
[    3.881356] usb 1-1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    3.893189] smsc95xx v1.0.4
[    3.956650] smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:4c:5c:c4
[    4.017707] EXT4-fs (mmcblk0p2): recovery complete
[    4.034877] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[    4.046372] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.
[    4.062671] usb 1-1.4: new high-speed USB device number 4 using dwc_otg
[    4.072303] devtmpfs: mounted
[    4.077952] Freeing unused kernel memory: 476K (807e7000 - 8085e000)
[    4.184281] usb 1-1.4: New USB device found, idVendor=0bda, idProduct=8178
[    4.193187] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    4.202426] usb 1-1.4: Product: USB WLAN
[    4.208222] usb 1-1.4: Manufacturer: Realtek
[    4.214330] usb 1-1.4: SerialNumber: 00e04c000001
[    4.489839] random: systemd urandom read with 67 bits of entropy available
[    4.504793] systemd[1]: systemd 215 running in system mode. (+PAM +AUDIT +SELINUX +IMA +SYSVINIT +LIBCRYPTSETUP +GCRYPT +ACL +XZ -SECCOMP -APPARMOR)
[    4.522435] systemd[1]: Detected architecture 'arm'.
[    4.693351] NET: Registered protocol family 10
[    4.701649] systemd[1]: Inserted module 'ipv6'
[    4.713047] systemd[1]: Set hostname to <raspberrypi>.
[    4.832839] uart-pl011 3f201000.uart: no DMA platform data
[    5.436553] systemd[1]: Expecting device dev-ttyAMA0.device...
[    5.446759] systemd[1]: Starting Forward Password Requests to Wall Directory Watch.
[    5.458127] systemd[1]: Started Forward Password Requests to Wall Directory Watch.
[    5.469295] systemd[1]: Starting Remote File Systems (Pre).
[    5.479009] systemd[1]: Reached target Remote File Systems (Pre).
[    5.487142] systemd[1]: Starting Encrypted Volumes.
[    5.496171] systemd[1]: Reached target Encrypted Volumes.
[    5.503578] systemd[1]: Starting Arbitrary Executable File Formats File System Automount Point.
[    5.518796] systemd[1]: Set up automount Arbitrary Executable File Formats File System Automount Point.
[    5.532196] systemd[1]: Starting Swap.
[    5.540324] systemd[1]: Reached target Swap.
[    5.546668] systemd[1]: Expecting device dev-mmcblk0p1.device...
[    5.556994] systemd[1]: Starting Root Slice.
[    5.565554] systemd[1]: Created slice Root Slice.
[    5.572143] systemd[1]: Starting User and Session Slice.
[    5.581682] systemd[1]: Created slice User and Session Slice.
[    5.589314] systemd[1]: Starting /dev/initctl Compatibility Named Pipe.
[    5.600129] systemd[1]: Listening on /dev/initctl Compatibility Named Pipe.
[    5.609035] systemd[1]: Starting Delayed Shutdown Socket.
[    5.618650] systemd[1]: Listening on Delayed Shutdown Socket.
[    5.626292] systemd[1]: Starting Journal Socket (/dev/log).
[    5.635936] systemd[1]: Listening on Journal Socket (/dev/log).
[    5.643691] systemd[1]: Starting udev Control Socket.
[    5.652708] systemd[1]: Listening on udev Control Socket.
[    5.659928] systemd[1]: Starting udev Kernel Socket.
[    5.668827] systemd[1]: Listening on udev Kernel Socket.
[    5.675993] systemd[1]: Starting Journal Socket.
[    5.684650] systemd[1]: Listening on Journal Socket.
[    5.691489] systemd[1]: Starting System Slice.
[    5.699987] systemd[1]: Created slice System Slice.
[    5.706726] systemd[1]: Starting File System Check on Root Device...
[    5.743453] systemd[1]: Starting system-systemd\x2dfsck.slice.
[    5.754021] systemd[1]: Created slice system-systemd\x2dfsck.slice.
[    5.762287] systemd[1]: Starting system-getty.slice.
[    5.772192] systemd[1]: Created slice system-getty.slice.
[    5.779661] systemd[1]: Starting system-serial\x2dgetty.slice.
[    5.790188] systemd[1]: Created slice system-serial\x2dgetty.slice.
[    5.798612] systemd[1]: Starting Increase datagram queue length...
[    5.812400] systemd[1]: Starting Restore / save the current clock...
[    5.851955] systemd[1]: Started Set Up Additional Binary Formats.
[    5.860280] systemd[1]: Mounted Huge Pages File System.
[    5.867556] systemd[1]: Starting udev Coldplug all Devices...
[    5.882243] systemd[1]: Starting Create list of required static device nodes for the current kernel...
[    5.942417] systemd[1]: Starting Load Kernel Modules...
[    5.957127] systemd[1]: Mounting Debug File System...
[    5.970909] systemd[1]: Mounting POSIX Message Queue File System...
[    5.986769] systemd[1]: Starting Slices.
[    5.995404] systemd[1]: Reached target Slices.
[    6.008965] systemd[1]: Started Increase datagram queue length.
[    6.050456] systemd[1]: Started Create list of required static device nodes for the current kernel.
[    6.068875] systemd[1]: Started Load Kernel Modules.
[    6.081078] systemd[1]: Mounted Debug File System.
[    6.093861] systemd[1]: Mounted POSIX Message Queue File System.
[    6.108274] systemd[1]: Started Restore / save the current clock.
[    6.121160] systemd[1]: Started udev Coldplug all Devices.
[    6.144201] systemd[1]: Time has been changed
[    6.316552] systemd[1]: Starting Apply Kernel Variables...
[    6.374143] systemd[1]: Mounting Configuration File System...
[    6.388764] systemd[1]: Mounted FUSE Control File System.

Raspbian GNU/Linux 8 raspberrypi ttyAMA0

raspberrypi login:

第一次登陆：

账户：pi
密码：raspberry

新的系统·罗列usb 状态

root@raspberrypi:/home/pi# lsusb
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
root@raspberrypi:/home/pi#

罗列系统mod状态

root@raspberrypi:/home/pi# lsmod
Module                  Size  Used by
cfg80211              427855  0
rfkill                 16037  1 cfg80211
snd_bcm2835            20511  0
snd_pcm                75698  1 snd_bcm2835
snd_timer              19160  1 snd_pcm
snd                    51844  3 snd_bcm2835,snd_timer,snd_pcm
bcm2835_gpiomem         3040  0
bcm2835_wdt             3225  0
uio_pdrv_genirq         3164  0
uio                     8000  1 uio_pdrv_genirq
ipv6                  347530  26
root@raspberrypi:/home/pi#

插上RTL8192cu芯片的usb网卡，不需要安装任何驱动，直接干活

罗列usb 状态

root@raspberrypi:/home/pi# lsusb
Bus 001 Device 004: ID 0bda:8178 Realtek Semiconductor Corp. RTL8192CU 802.11n WLAN Adapter
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

罗列系统mod状态

root@raspberrypi:/home/pi# lsmod
Module                  Size  Used by
8192cu                519156  0
cfg80211              427855  0
rfkill                 16037  2 cfg80211
snd_bcm2835            20511  0
snd_pcm                75698  1 snd_bcm2835
snd_timer              19160  1 snd_pcm
snd                    51844  3 snd_bcm2835,snd_timer,snd_pcm
bcm2835_gpiomem         3040  0
bcm2835_wdt             3225  0
uio_pdrv_genirq         3164  0
uio                     8000  1 uio_pdrv_genirq
ipv6                  347530  26

扫描附近wifi状态

root@raspberrypi:/home/pi# iwlist wlan0 scanning
wlan0     Scan completed :
Cell 01 - Address: D8:B0:4C:E0:A1:1B
ESSID:"XEEDER4CE0A11A"
Protocol:IEEE 802.11bgn
Mode:Master
Frequency:2.412 GHz (Channel 1)
Encryption key:off
Bit Rates:72 Mb/s
Quality:47  Signal level:0  Noise level:0
Cell 02 - Address: D8:B0:4C:E0:9B:65
ESSID:"XEEDER4CE09B64"
Protocol:IEEE 802.11bgn
Mode:Master
Frequency:2.412 GHz (Channel 1)
Encryption key:off
Bit Rates:72 Mb/s
Quality:44  Signal level:0  Noise level:0

树莓派无线网卡上网方式1

使用DHCP方式联网，无线路由器的配置：3个条件 开启DHCP服务，有SSID，有密码，

配置树莓派的网络：

Linux_树莓派@http://990487026.blog.51cto.com:~# 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

iface eth0 inet manual

auto wlan0
allow-hotplug wlan0 #表示wlan设备可以热插拨
iface wlan0 inet dhcp
wpa-ssid haha_ssid
wpa-psk  haha_password

Linux_树莓派@http://990487026.blog.51cto.com:~#

重启网卡设备，并测试

Linux_树莓派@http://990487026.blog.51cto.com:~# ifdown wlan0 && ifup wlan0

测试
Linux_树莓派@http://990487026.blog.51cto.com:~# ping www.jd.com
PING www.jdcdn.com (61.174.55.1) 56(84) bytes of data.
64 bytes from 1.55.174.61.dial.wz.zj.dynamic.163data.com.cn (61.174.55.1): icmp_seq=1 ttl=55 time=12.4 ms
64 bytes from 1.55.174.61.dial.wz.zj.dynamic.163data.com.cn (61.174.55.1): icmp_seq=2 ttl=55 time=11.6 ms
64 bytes from 1.55.174.61.dial.wz.zj.dynamic.163data.com.cn (61.174.55.1): icmp_seq=3 ttl=55 time=14.8 ms
64 bytes from 1.55.174.61.dial.wz.zj.dynamic.163data.com.cn (61.174.55.1): icmp_seq=4 ttl=55 time=12.7 ms
^C
--- www.jdcdn.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3005ms
rtt min/avg/max/mdev = 11.644/12.919/14.804/1.166 ms
Linux_树莓派@http://990487026.blog.51cto.com:~#

树莓派无线网卡上网方式2

使用static方式联网，无线路由器的配置：3个条件 关闭DHCP服务，有SSID，有密码，

Linux_树莓派@http://990487026.blog.51cto.com:~# 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

iface eth0 inet manual

auto wlan0
allow-hotplug wlan0 #表示wlan设备可以热插拨
iface wlan0 inet static
wpa-ssid xiaomiAP
wpa-psk  apple2016
address 10.11.12.103
netmask 255.255.255.0
gateway 10.11.12.13
dns-nameservers 180.76.76.76 223.5.5.5

Linux_树莓派@http://990487026.blog.51cto.com:~#

配置好了，必须重启一下。ifdown wlan0 && ifup wlan0这条命令不管用

【重启】

Linux_树莓派@http://990487026.blog.51cto.com:~# reboot
登陆树莓派，测试
Linux_树莓派@http://990487026.blog.51cto.com:~# ping www.taobao.com
PING www.taobao.com.danuoyi.tbcache.com (183.136.138.188) 56(84) bytes of data.
64 bytes from 183.136.138.188: icmp_seq=1 ttl=50 time=17.0 ms
64 bytes from 183.136.138.188: icmp_seq=2 ttl=50 time=15.7 ms
64 bytes from 183.136.138.188: icmp_seq=3 ttl=50 time=22.4 ms
64 bytes from 183.136.138.188: icmp_seq=4 ttl=50 time=18.0 ms
^C
--- www.taobao.com.danuoyi.tbcache.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 15.793/18.315/22.412/2.499 ms
Linux_树莓派@http://990487026.blog.51cto.com:~#

查看wifi网络状态：

Linux_树莓派@http://990487026.blog.51cto.com:~# iwconfig wlan0
wlan0     IEEE 802.11bgn  ESSID:"xiaomiAP"  Nickname:"<WIFI@REALTEK>"
Mode:Managed  Frequency:2.427 GHz  Access Point: 5C:63:BF:BA:67:3E
Bit Rate:300 Mb/s   Sensitivity:0/0
Retry:off   RTS thr:off   Fragment thr:off
Encryption key:****-****-****-****-****-****-****-****   Security mode:open
Power Management:off
Link Quality=100/100  Signal level=93/100  Noise level=0/100
Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
Tx excessive retries:0  Invalid misc:0   Missed beacon:0

Linux_树莓派@http://990487026.blog.51cto.com:~#

无线与双绞线的延时差别：

无线
chunli@http://990487026.blog.51cto.com:~$ ping -c 100 10.11.12.13
--- 10.11.12.13 ping statistics ---
100 packets transmitted, 100 received, 0% packet loss, time 99150ms
rtt min/avg/max/mdev = 3.026/8.573/31.087/5.941 ms
chunli@http://990487026.blog.51cto.com:~$

有线
chunli@http://990487026.blog.51cto.com:~$ ping -c 100 10.11.12.13
--- 10.11.12.13 ping statistics ---
100 packets transmitted, 100 received, 0% packet loss, time 99204ms
rtt min/avg/max/mdev = 1.004/1.317/12.890/1.203 ms
chunli@http://990487026.blog.51cto.com~$

恭喜你！

现在可以在linux下面干活了！