【自我提高】树莓派GPIO的几种语言控制方法 C 篇

使用C语言控制 GPIO.18

首先知道树莓派外置IO的关系对照表
我这里的树莓派是： PI 3B + V1.2
关系对照表如下：

C 语言下使用 wiringPi GPIO 进行编程

要安装 wiringPi

pi@raspberrypi:~ $ sudo apt-get update
pi@raspberrypi:~ $ sudo apt-get upgrade
pi@raspberrypi:~ $ sudo apt-get install wiringpi

测试 wiringPi 是否安装成功

pi@raspberrypi:~/pilearn $ gpio -v
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 3, Revision: 02, Memory: 1024MB, Maker: Embest 
  * Device tree is enabled.
  *--> Raspberry Pi 3 Model B Rev 1.2
  * This Raspberry Pi supports user-level GPIO access.

使用 wiringPi 查看树莓派引脚对应关系：

pi@raspberrypi:~/pilearn $  gpio readall
 +-----+-----+---------+------+---+---Pi 3B--+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 0 | IN   | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | OUT  | 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 |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | 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 3B--+---+------+---------+-----+-----+

树莓派的GPIO编码方式

1、功能物理引脚：
	从左到右，从上到下：左边基数，右边偶数：1-40
2、BCM:
	编号侧重CPU寄存器，根据BCM2835的GPIO寄存器编号。
3、wpi：
	  编号侧重实现逻辑，把扩展GPIO端口从0开始编号，这种编号方便编程。

代码如下：

#include <wiringPi.h>
#include <stdio.h>

int main(void) {
		wiringPiSetup();
		pinMode (1, OUTPUT);
		for(;;) {
			
			digitalWrite(1, HIGH);
			printf("GPIO_18 IS HIGH \n");
			delay (500);
			
			digitalWrite(1, LOW);
			printf("GPIO_18 IS LOW  \n");
			delay (500);
			
		}
}

运行程序前需要编译，由于引入外部库，编译时要 link 相应的库

编译并执行：

pi@raspberrypi:~/pilearn $ gcc led.c -o led -l wiringPi
pi@raspberrypi:~/pilearn $ ls
led  led.c
pi@raspberrypi:~/pilearn $ ./led 
GPIO_18 IS HIGH 
GPIO_18 IS LOW  
GPIO_18 IS HIGH 
GPIO_18 IS LOW  
GPIO_18 IS HIGH 
GPIO_18 IS LOW  
GPIO_18 IS HIGH 
GPIO_18 IS LOW  

wiringPi 的详细使用方式查阅 http://wiringpi.com/