[RaspberryPi] Pi上自带的wiringPi库

首先，感谢@drogon一直为树莓派提供GPIO操作库wiringPi的支持与维护，我们感谢这些无私奉献的人。wiringPi的官方网站请访问：http://wiringpi.com/

Pi中内建的wiringPi库其实功能是非常强大的，不仅在pi中有直接提供wiringPi库包含以下一个部分的内容：

• 头文件可用于开发各种基于GPIO、I2C、SPI、UART等接口的应用和模块
• 基于wiringPi封装的各种常见硬件模块的驱动库与其头文件
• 命令行下GPIO相关工具

基于wiringPi库的驱动库

TODO

GPIO命令行工具

wiringPi提供的命令行GPIO工具名为gpio，

GPIO工具帮助

gpio: Usage: gpio -v          // 显示wiringPi的版本信息
       gpio -h                // 显示此帮助列表
       gpio [-g|-1] ...
       gpio [-d] ...
       [-x extension:params] [[ -x ...]] ...
       gpio [-p] <read/write/wb> ...
       gpio <mode/read/write/aread/awritewb/pwm/pwmTone/clock> ...
       gpio <toggle/blink> <pin>
       gpio readall            // 显示所有引脚的信息
       gpio unexportall/exports  // 
       gpio export/edge/unexport ...
       gpio wfi <pin> <mode>
       gpio drive <group> <value>
       gpio pwm-bal/pwm-ms
       gpio pwmr <range>
       gpio pwmc <divider>
       gpio load spi/i2c
       gpio unload spi/i2c
       gpio i2cd/i2cdetect
       gpio rbx/rbd
       gpio wb <value>
       gpio usbp high/low
       gpio gbr <channel>
       gpio gbw <channel> <value>

wiringPi版本信息

gpio -v

显示wiringPi及Pi的版本信息

gpio version: 2.50
Copyright (c) 2012-2018 Gordon Henderson
This is free software with ABSOLUTELY NO WARRANTY.
For details type: gpio -warranty

Raspberry Pi Details:
  Type: Pi 2, Revision: 01, Memory: 1024MB, Maker: Embest
  * Device tree is enabled.
  *--> Raspberry Pi 2 Model B Rev 1.1
  * This Raspberry Pi supports user-level GPIO access.

GPIO信息查阅

gpio readall

你会获得Pi上GPIO的状态map，如下：

 +-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 | ALT0 | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 | ALT0 | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 0 |  7 || 8  | 1 | ALT0 | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | ALT0 | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 0 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI | ALT0 | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO | ALT0 | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK | ALT0 | 0 | 23 || 24 | 1 | OUT  | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | OUT  | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 0 | IN   | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 0 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 0 | 35 || 36 | 0 | IN   | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 0 | 37 || 38 | 0 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 0 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+