树莓派从零开始学习记录

树莓派学习从零开始

• 树莓派系统的安装

  使用官方推荐的TF卡烧写工具 Win32DiskImager写入镜像2016-09-23-raspbian-jessie.img

• 连接树莓派

  最简单的连接方法是： （此方法需要电脑无线连接至网络）

  1. 使用一根网线连接笔记本（笔记本已连接到无线网）和树莓派
  2. 电脑端安装putty软件

  3. 依次打开网络和共享中心–更改适配器设置``无线网络连接属性–共享–勾选允许其他网络用户通过此计算机的Internet连接来连接---本地连接

     如图：
     

  4. 电脑端win+R打开cmdshell，输入：arp -a

     Microsoft Windows [版本 6.1.7601]
     版权所有 (c) 2009 Microsoft Corporation。保留所有权利。
     
     C:\Users\Administrator>arp -a
     
     接口: 192.168.137.1 --- 0xc
       Internet 地址         物理地址              类型
       192.168.137.210       b8-xx-xx-xx-xx-eb     动态
       192.168.137.255       ff-ff-ff-ff-ff-ff     静态
       224.0.0.22            01-00-5e-00-00-16     静态
       224.0.0.252           01-00-5e-00-00-fc     静态
       239.255.255.250       01-00-5e-7f-ff-fa     静态
       255.255.255.255       ff-ff-ff-ff-ff-ff     静态
     
     接口: 192.168.0.108 --- 0xd
       Internet 地址         物理地址              类型
       192.168.0.1           c8-3a-35-5e-ef-10     动态
       192.168.0.107         b8-xx-xx-xx-xx-be     动态
       192.168.0.109         8c-89-a5-72-07-5e     动态
       192.168.0.110         40-c6-2a-2c-86-ef     动态
       192.168.0.255         ff-ff-ff-ff-ff-ff     静态
       224.0.0.22            01-00-5e-00-00-16     静态
       224.0.0.252           01-00-5e-00-00-fc     静态
       239.255.255.250       01-00-5e-7f-ff-fa     静态
       255.255.255.255       ff-ff-ff-ff-ff-ff     静态
     
     C:\Users\Administrator>
     

     查看接口“192.168.137.1 —0xc”下的 动态IP
     即：192.168.137.210 ，后面的MAC地址便是树莓派的有线网卡的物理地址

  5. 打开putty输入该动态IP，便可进入树莓派的shell界面

     注意 　使用该方法连接树莓派，树莓派在重启或者重连后其动态IP都会改变，每次连接都要重新查看其新的动态IP，建议，首先对树莓派配置无线网络

• 修改默认账户”pi”的初始密码

  树莓派默认账户是pi，初始密码是raspberry
  修改pi的密码如下

  pi@raspberrypi:/ $ passwd pi
  Changing password for pi.
  (current) UNIX password:
  Enter new UNIX password:
  Retype new UNIX password:
  

• 解锁root账户、设置root账户密码

  树莓派使用的linux是debian系统，所以树莓派启用root和debian是相同的。
  debian里root账户默认没有密码，但账户锁定。

  当需要root权限时，由默认账户经由sudo执行，Raspberry pi 系统中的
  Raspbian默认用户是pi 密码为raspberry
  重新开启root账号，可由pi用户登录后，在命令行下执行

  pi@raspberrypi:~ $ sudo passwd root
  Enter new UNIX password:
  Retype new UNIX password:
  passwd: password updated successfully
  

  执行此命令后系统会提示输入两遍的root密码，输入你想设的密码即可，然后在执行
  sudo passwd --unlock root

  pi@raspberrypi:~ $ sudo passwd --unlock root
  passwd: password expiry information changed.
  

  这样就可以解锁root账户了。

• 创建新账号并设置密码

  创建用户johnwick 　命令useradd

  root@raspberrypi:/home/pi# useradd johnwick
  

  给新账户设置密码

  root@raspberrypi:/home/pi# passwd johnwick
  Enter new UNIX password:
  

• 添加新用户到sudo组

  切换到root账户，输入指令visudo

  pi@raspberrypi:~ $ su
  Password:
  root@raspberrypi:/home/pi# visudo
  

  在文档的最后一行添加账户johnwick，配置：执行sudo命令式免密码，保存。

  # This file MUST be edited with the 'visudo' command as root.
  #
  # Please consider adding local content in /etc/sudoers.d/ instead of
  # directly modifying this file.
  #
  # See the man page for details on how to write a sudoers file.
  #
  Defaults        env_reset
  Defaults        mail_badpass
  Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
  
  # Host alias specification
  
  # User alias specification
  
  # Cmnd alias specification
  
  # User privilege specification
  root    ALL=(ALL:ALL) ALL
  
  # Allow members of group sudo to execute any command
  %sudo   ALL=(ALL:ALL) ALL
  
  # See sudoers(5) for more information on "#include" directives:
  
  #includedir /etc/sudoers.d
  
  pi ALL=(ALL) NOPASSWD: ALL
  
  johnwick  ALL=(ALL) NOPASSWD: ALL        
  

• 自定义用户的命令行提示符颜色

  为了方便也为了美观，需要对shell界面的命令提示符的颜色进行配置
  修改root账户下的.bashrc文件
  先找到root账户的家目录

  注意：配置哪个账户就到哪个账户的家目录下修改.bashrc文件，一定不要修改了全局环境量
  　比如：给johnwick账户配颜色，就先

  [root@raspberrypi/home/johnwick]#su johnwick
  johnwick@raspberrypi:~ $ cd ~
  johnwick@raspberrypi:~ $ sudo .bashrc
  #把PS1="\[\e[37;40m\][\[\e[32;40m\]\u\[\e[37;40m\]@\h\[\e[36;40m\]\w\[\e[0m\]]\\$"复制到最后一行
  #重新加载`.bashrc`文件
  johnwick@raspberrypi:~ $ source .bashrc
  

  >

  root@raspberrypi:/home# cd ~ 
  再使用`nano`打开存放环境变量的文件`.bashrc`       
  # ~/.bashrc: executed by bash(1) for non-login shells.
  
  # Note: PS1 and umask are already set in /etc/profile. You should not
  # need this unless you want different defaults for root.
  # PS1='${debian_chroot:+($debian_chroot)}\h:\w\$ '
  # umask 022
  
  # You may uncomment the following lines if you want `ls' to be colorized:
  # export LS_OPTIONS='--color=auto'
  # eval "`dircolors`"
  # alias ls='ls $LS_OPTIONS'
  # alias ll='ls $LS_OPTIONS -l'
  # alias l='ls $LS_OPTIONS -lA'
  #
  # Some more alias to avoid making mistakes:
  # alias rm='rm -i'
  # alias cp='cp -i'
  # alias mv='mv -i'
  PS1="\[\e[37;40m\][\[\e[31;40m\]\u\[\e[37;40m\]@\h\[\e[36;40m\]\w\[\e[0m\]]\\$"
  

  >

  在最后面添加上配置好的自己喜欢的字体颜色配置
  配置完成后重新加载.bashrc文件 命令：root@raspberrypi:~# source .bashrc

  我常用的三个账户的颜色配置方案：

      绿色
      PS1="\[\e[37;40m\][\[\e[32;40m\]\u\[\e[37;40m\]@\h\[\e[36;40m\]\w\[\e[0m\]]\\$"
      黄色
      PS1="\[\e[37;40m\][\[\e[33;40m\]\u\[\e[37;40m\]@\h\[\e[36;40m\]\w\[\e[0m\]]\\$"
      红色
      PS1="\[\e[37;40m\][\[\e[31;40m\]\u\[\e[37;40m\]@\h\[\e[36;40m\]\w\[\e[0m\]]\\$"
  

• 创建get.py文件，运行后显示树莓派的CPU温度RAM、ROM

  创建get.py文件　直接使用命令

  [johnwick@raspberrypi~]$nano get.py
  

  把下面的代码写进get.py文件，并保存，退出。

      import os
  
  # Return CPU temperature as a character string                                     
  def getCPUtemperature():
      res = os.popen('sudo cat /sys/class/thermal/thermal_zone0/temp').readline()
      tempfloat=float(res) / 1000
      temp=str(tempfloat)
      return(temp)
  
  
  # Return RAM information (unit=kb) in a list                                      
  # Index 0: total RAM                                                              
  # Index 1: used RAM                                                                
  # Index 2: free RAM                                                                
  def getRAMinfo():
      p = os.popen('free')
      i = 0
      while 1:
          i = i + 1
          line = p.readline()
          if i==2:
              return(line.split()[1:4])
  
  # Return % of CPU used by user as a character string                               
  def getCPUuse():
      return(str(os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip()))
  
  # Return information about disk space as a list (unit included)                    
  # Index 0: total disk space                                                        
  # Index 1: used disk space                                                        
  # Index 2: remaining disk space                                                    
  # Index 3: percentage of disk used                                                 
  def getDiskSpace():
      p = os.popen("df -h /")
      i = 0
      while 1:
          i = i +1
          line = p.readline()
          if i==2:
              return(line.split()[1:5])
  
  
  # CPU informatiom
  CPU_temp = getCPUtemperature()
  CPU_usage = getCPUuse()
  
  # RAM information
  # Output is in kb, here I convert it in Mb for readability
  RAM_stats = getRAMinfo()
  RAM_total = round(int(RAM_stats[0]) / 1000,1)
  RAM_used = round(int(RAM_stats[1]) / 1000,1)
  RAM_free = round(int(RAM_stats[2]) / 1000,1)
  
  # Disk information
  DISK_stats = getDiskSpace()
  DISK_total = DISK_stats[0]
  DISK_used = DISK_stats[1]
  DISK_perc = DISK_stats[3]
  
  if __name__ == '__main__':
      print('')
      print('CPU Temperature = '+CPU_temp)
      print('CPU Use = '+CPU_usage)
      print('')
      print('RAM Total = '+str(RAM_total)+' MB')
      print('RAM Used = '+str(RAM_used)+' MB')
      print('RAM Free = '+str(RAM_free)+' MB')
      print('') 
      print('DISK Total Space = '+str(DISK_total)+'B')
      print('DISK Used Space = '+str(DISK_used)+'B')
      print('DISK Used Percentage = '+str(DISK_perc))
  

  运行get.py文件

  [johnwick@raspberrypi~]$sudo python get.py
  
  CPU Temperature = 40.242
  CPU Use = 0.1
  
  RAM Total = 947.0 MB
  RAM Used = 225.0 MB
  RAM Free = 722.0 MB
  
  DISK Total Space = 30GB
  DISK Used Space = 3.7GB
  DISK Used Percentage = 13%
  

• 查看周围的无线网络的ESSID(网络名称)、网络信息、信号强度

  命令：　iwlist scan

  [johnwick@raspberrypi~]$sudo iwlist scan
  wlan0     Scan completed :
    Cell 01 - Address: C8:3A:35:5E:EF:10
              Channel:1
              Frequency:2.412 GHz (Channel 1)
              Quality=44/70  Signal level=-66 dBm
              Encryption key:on
              ESSID:"Tenda_5EEF10"
              Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                        24 Mb/s; 36 Mb/s; 54 Mb/s
              Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s
              Mode:Master
              Extra:tsf=0000000000000000
              Extra: Last beacon: 80ms ago
              IE: Unknown: 000C54656E64615F354545463130
              IE: Unknown: 010882840B162430486C
              IE: Unknown: 030101
              IE: Unknown: 2A0104
              IE: Unknown: 2F0104
              IE: Unknown: 32040C121860
              IE: Unknown: 2D1AFE181BFFFF000001000000000000000000000000000                                                                                        000000000
              IE: Unknown: 3D16010D000000000000000000000000000000000000000                                                                                        0
              IE: Unknown: DD090010180202F02C0000
              IE: WPA Version 1
                  Group Cipher : CCMP
                  Pairwise Ciphers (1) : CCMP
                  Authentication Suites (1) : PSK
              IE: Unknown: DD180050F2020101000003A4000027A4000042435E00623                                                                                        22F00
    Cell 02 - Address: C8:3A:35:52:FC:30
              Channel:6
              Frequency:2.437 GHz (Channel 6)
              Quality=35/70  Signal level=-75 dBm
              Encryption key:on
              ESSID:"WXtencent"
              Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                        24 Mb/s; 36 Mb/s; 54 Mb/s
              Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s
              Mode:Master
              Extra:tsf=0000000000000000
              Extra: Last beacon: 80ms ago
              IE: Unknown: 0009575874656E63656E74
              IE: Unknown: 010882840B162430486C
              IE: Unknown: 030106
              IE: Unknown: 2A0100
              IE: Unknown: 2F0100
              IE: IEEE 802.11i/WPA2 Version 1
                  Group Cipher : CCMP
                  Pairwise Ciphers (1) : CCMP
                  Authentication Suites (1) : PSK
              IE: Unknown: 32040C121860
              IE: Unknown: 2D1AFE181BFFFF000001000000000000000000000000000                                                                                        000000000
              IE: Unknown: 3D16060D000000000000000000000000000000000000000                                                                                        0
              IE: Unknown: DD090010180203102C0000
              IE: WPA Version 1
                  Group Cipher : CCMP
                  Pairwise Ciphers (1) : CCMP
                  Authentication Suites (1) : PSK
              IE: Unknown: DD180050F2020101000003A4000027A4000042435E00623                                                                                        22F00
    Cell 03 - Address: 58:6A:B1:1C:B2:10
              Channel:11
              Frequency:2.462 GHz (Channel 11)
              Quality=26/70  Signal level=-84 dBm
              Encryption key:on
              ESSID:"111111"
              Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
                        11 Mb/s; 12 Mb/s; 18 Mb/s
              Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
              Mode:Master
              Extra:tsf=0000000000000000
              Extra: Last beacon: 80ms ago
              IE: Unknown: 0006313131313131
              IE: Unknown: 010882848B0C12961824
              IE: Unknown: 03010B
              IE: Unknown: 0706434E49010D14
              IE: Unknown: 2A0100
              IE: IEEE 802.11i/WPA2 Version 1
                  Group Cipher : CCMP
                  Pairwise Ciphers (1) : CCMP
                  Authentication Suites (1) : PSK
              IE: Unknown: 32043048606C
              IE: Unknown: 2D1AEC1103FFFF000000000000000000000000000000000                                                                                        000000000
              IE: Unknown: 3D160B08040000000000000000000000000000000000000                                                                                        0
              IE: Unknown: DD180050F2020101810003A4000027A4000042435E00623                                                                                        22F00
              IE: Unknown: DD1E00904C33EC1103FFFF0000000000000000000000000                                                                                        00000000000000000
              IE: Unknown: DD1A00904C340B080400000000000000000000000000000                                                                                        000000000
    Cell 04 - Address: F4:83:CD:53:F0:05
              Channel:1
              Frequency:2.412 GHz (Channel 1)
              Quality=52/70  Signal level=-58 dBm
              Encryption key:on
              ESSID:"TP-LINK_F005"
              Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                        9 Mb/s; 12 Mb/s; 18 Mb/s
              Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
              Mode:Master
              Extra:tsf=0000000000000000
              Extra: Last beacon: 80ms ago
              IE: Unknown: 000C54502D4C494E4B5F46303035
              IE: Unknown: 010882848B960C121824
              IE: Unknown: 030101
              IE: Unknown: 2A0100
              IE: IEEE 802.11i/WPA2 Version 1
                  Group Cipher : CCMP
                  Pairwise Ciphers (1) : CCMP
                  Authentication Suites (1) : PSK
              IE: Unknown: 32043048606C
              IE: Unknown: 2D1AEE111BFFFFFF0000000000000000000100000000000                                                                                        000000000
              IE: Unknown: 3D16010D060000000000000000000000000000000000000                                                                                        0
              IE: Unknown: 7F080000000000000040
              IE: WPA Version 1
                  Group Cipher : CCMP
                  Pairwise Ciphers (1) : CCMP
                  Authentication Suites (1) : PSK
              IE: Unknown: DD180050F2020101000003A4000027A4000042435E00623                                                                                        22F00
              IE: Unknown: DD0900037F01010000FF7F
      lo        Interface doesn't support scanning.           
      eth0      Interface doesn't support scanning.
  

• 配置树莓派无线网络

  树莓派可以存储多个网络的信息，将常用的几个网络的ssid和psk配置好，一并存储即可，这样，当树莓派更换网络后也会自动连接

  # 编辑wifi文件
  sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
  # 在该文件最后添加下面的话
  network={
    ssid="WIFINAME"
    psk="password"
  }
  # 引号部分分别为wifi的名字和密码
  # 保存文件后几秒钟应该就会自动连接到该wifi
  # 查看是否连接成功
  ifconfig wlan0
  

  查看树莓派网卡信息（IP地址、有线网卡和无线网卡的MAC地址）

          [johnwick@raspberrypi~]$ifconfig
  eth0      Link encap:Ethernet  HWaddr b8:xx:xx:xx:xx:eb
            inet addr:192.168.137.26  Bcast:192.168.137.255  Mask:255.255.255.0
            inet6 addr: fe80::4152:ce36:8645:2e67/64 Scope:Link
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:2417 errors:0 dropped:0 overruns:0 frame:0
            TX packets:1220 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000
            RX bytes:193242 (188.7 KiB)  TX bytes:178039 (173.8 KiB)
  
  lo        Link encap:Local Loopback
            inet addr:127.0.0.1  Mask:255.0.0.0
            inet6 addr: ::1/128 Scope:Host
            UP LOOPBACK RUNNING  MTU:65536  Metric:1
            RX packets:264 errors:0 dropped:0 overruns:0 frame:0
            TX packets:264 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1
            RX bytes:21840 (21.3 KiB)  TX bytes:21840 (21.3 KiB)
  
  wlan0     Link encap:Ethernet  HWaddr b8:xx:xx:xx:xx:be
            inet6 addr: fe80::5151:9360:9963:5f17/64 Scope:Link
            UP BROADCAST MULTICAST  MTU:1500  Metric:1
            RX packets:665 errors:0 dropped:665 overruns:0 frame:0
            TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000
            RX bytes:237933 (232.3 KiB)  TX bytes:0 (0.0 B)
  

• 无法登陆路由器管理界面的情况下如何查看树莓派的无线IP地址

  有时，使用树莓派连接外界网络（知道账号和密码，但不能进入管理界面查看已经连接无线网络的树莓派的无线IP地址），此时，我们可以继续使用之前的方法，使用一根网线连接笔记本，通过动态IP地址ssh到shell然后查看pI的网络信息

  [johnwick@raspberrypi~]$ifconfig wlan0
  wlan0     Link encap:Ethernet  HWaddr b8:xx:xx:xx:xx:be
            inet addr:192.168.0.159  Bcast:192.168.0.255  Mask:255.255.255.0
            inet6 addr: fe80::5151:9360:9963:5f17/64 Scope:Link
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:2096 errors:0 dropped:938 overruns:0 frame:0
            TX packets:227 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000
            RX bytes:262474 (256.3 KiB)  TX bytes:39358 (38.4 KiB)
  

  使用此方法可以省去网线连接笔记本的不便，但也比不上配置固定IP方便
  ，

• 配置路由器端口映射

  1. 给树莓派绑定静态IP
  2. 设置端口段映射
  3. 选择DDNS服务商，做动态DNS解析
     

  以上步骤均从路由器端进行设置，设置完成后即可局域网内或者外网访问树莓派主机

• 设置时区

  [johnwick@raspberrypi~]$sudo dpkg-reconfigure tzdata
  
  Package configuration
  
    ┌─────────────────────────┤ Configuring tzdata ├──────────────────────────┐
    │ Please select the geographic area in which you live. Subsequent         │
    │ configuration questions will narrow this down by presenting a list of   │
    │ cities, representing the time zones in which they are located.          │
    │                                                                         │
    │ Geographic area:                                                        │
    │                                                                         │
    │                          Africa                ↑                        │
    │                          America               ▒                        │
    │                          Antarctica            ▒                        │
    │                          Australia             ▮                        │
    │                          Arctic Ocean          ▒                        │
    │                          Asia                  ▒                        │
    │                          Atlantic Ocean        ▒                        │
    │                          Europe                ↓                        │
    │                                                                         │
    │                                                                         │
    │                                                             │
    │                                                                         │
    └─────────────────────────────────────────────────────────────────────────┘
  

  选择Asia>>chongqing或者shanghai