GPIO控制-09

AIOTNIK-ONE开发板预留了一排GPIO，可以当作普通的IO口来使用。原理图和实物图如下。

以下是GPIO的使用代码示例，实现主控输出GPIO口的高低电压。

/*
*gpio_test.c
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <fcntl.h>
#include <stdbool.h>
#include <sys/time.h>
#include <errno.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <netinet/tcp.h>
int open_gpio_port(int gpiogroup, int gpio, char *mode)
{
 /*
 PA(n) = 0 * 32 + n
 PB(n) = 1 * 32 + n
 PC(n) = 2 * 32 + n
 ...
 例如：申请 PB(10) = 1 * 32 + 10 = 42
 */
 int fd, fd0;
 /* gpio0 = 1*32 + 18 */
 int gpio0 = gpiogroup*32 + gpio;
 char tmp[128];
 fd = open("/sys/class/gpio/export", O_WRONLY);
 if(fd < 0) {
 printf("open /sys/class/gpio/export error !");
 return -1;
 }
 sprintf(tmp, "%d", gpio0);
 write(fd, tmp, 2);
 close(fd);
 sprintf(tmp, "/sys/class/gpio/gpio%d/direction", gpio0);
 fd0 = open(tmp, O_RDWR);
 if(fd0 < 0) {
 printf("open /sys/class/gpio/gpio%d/direction error !", gpio0);
 return -1;
 }
 write(fd0, mode, strlen(mode));
 close(fd0);
 sprintf(tmp, "/sys/class/gpio/gpio%d/active_low", gpio0);
 fd0 = open(tmp, O_RDWR);
 if(fd0 < 0) {
 printf("open /sys/class/gpio/gpio%d/active_low error !", gpio0);
 return -1;
 }
 write(fd0, "1", 0);
 close(fd0);
 return 0;
}
int read_gpio_value(int gpiogroup, int gpio, int *value)
{
 /*
 PA(n) = 0 * 32 + n
 PB(n) = 1 * 32 + n
 PC(n) = 2 * 32 + n
 ...
 例如：申请 PB(10) = 1 * 32 + 10 = 42
 */
 int fd0;
 /* gpio0 = 1*32 + 18 */
 int gpio0 = gpiogroup*32 + gpio;
 char tmp[128];
 sprintf(tmp, "/sys/class/gpio/gpio%d/value", gpio0);
 fd0 = open(tmp, O_RDWR);
 if(fd0 < 0) {
 printf("open /sys/class/gpio/gpio%d/value error !", gpio0);
 return -1;
 }
 char buf[2] = {"\0"};
 read(fd0, buf, 1);
 if(buf[0] == '1')
 {
 *value = 1;
 }
 else if(buf[0] == '0'){
 *value = 0;
 }
 close(fd0);
 return *value;
}
int write_gpio_value(int gpiogroup, int gpio, int value)
{
 /*
 PA(n) = 0 * 32 + n
 PB(n) = 1 * 32 + n
 PC(n) = 2 * 32 + n
 ...
 例如：申请 PB(10) = 1 * 32 + 10 = 42
 */
 int fd0;
 int gpio0 = gpiogroup*32 + gpio;
 char tmp[128];
 char on[4] = {0};
 sprintf(tmp, "/sys/class/gpio/gpio%d/value", gpio0);
 fd0 = open(tmp, O_RDWR);
 if(fd0 < 0) {
 printf("open /sys/class/gpio/gpio%d/value error !", gpio0);
 return -1;
 }
 sprintf(on,"%d", value);
 write(fd0, on, strlen(on));
 close(fd0);
 return 0;
}
/*
*gpiogroup: gpio组，例如PA，PB，PC
*gpio：gpio序号，如pa14, pb15, pc16
*mode: gpio模式，in：表示设置为输入；out：表示设置为输出
*value：高低电平，0：低电平；1：高电平
*/
int set_gpio_value(int gpiogroup, int gpio, char *mode, int value)
{
 int ret = -1;
 ret = open_gpio_port(gpiogroup, gpio, mode);
 if(ret == -1){
 printf("open_gpio_port failed!\n");
 return ret;
 }
 ret = write_gpio_value(gpiogroup, gpio, value);
 if(ret == -1){
 printf("write_gpio_value failed!\n");
 return ret;
 }
 return 0;
}
int get_gpio_value(int gpiogroup, int gpio, char *mode, int *value)
{
 int ret = -1;
 ret = open_gpio_port(gpiogroup, gpio, mode);
 if(ret == -1){
 printf("open_gpio_port failed!\n");
 return ret;
 }
 ret = read_gpio_value(gpiogroup, gpio, value);
 if(ret == -1){
 printf("read_gpio_value failed!\n");
 return ret;
 }
 return  *value;
}
int main()
{
 set_gpio_value(2, 14, "out", 1);//将pc14设置为高电平
 set_gpio_value(2, 14, "out", 0);//将pc14设置为低电平
 set_gpio_value(2, 15, "out", 1);//将pc15设置为高电平
 set_gpio_value(2, 16, "out", 1);//将pc16设置为高电平
 return 0;
}