C语言交叉编译控制LED

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stormwind123| 中级工程师

楼主 | 2023-9-22 15:57 | 只看该作者回帖奖励

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#include

#include

#include

#include

#include  //define O_WRONLY and O_RDONLY

// LED 引脚

#define SYSFS_GPIO_EXPORT "/sys/class/gpio/export"

#define SYSFS_GPIO_UNEXPORT "/sys/class/gpio/unexport"

#define SYSFS_GPIO_RST_PIN_VAL "440"

#define SYSFS_GPIO_RST_DIR "/sys/class/gpio/gpio440/direction"

#define SYSFS_GPIO_RST_DIR_VAL "OUT"

#define SYSFS_GPIO_RST_VAL "/sys/class/gpio/gpio440/value"

#define SYSFS_GPIO_RST_VAL_H "1"

#define SYSFS_GPIO_RST_VAL_L "0"

int main()

{

int fd;

int count = 30;

// 打开端口/sys/class/gpio# echo 440 > export

fd = open(SYSFS_GPIO_EXPORT, O_WRONLY);

if (fd == -1)

{

      printf("ERR: export open error.\n");

      return EXIT_FAILURE;

}

write(fd, SYSFS_GPIO_RST_PIN_VAL, sizeof(SYSFS_GPIO_RST_PIN_VAL));

close(fd);

// 设置端口方向/sys/class/gpio/gpio440# echo out > direction

fd = open(SYSFS_GPIO_RST_DIR, O_WRONLY);

if (fd == -1)

{

      printf("ERR: direction open error.\n");

      return EXIT_FAILURE;

}

write(fd, SYSFS_GPIO_RST_DIR_VAL, sizeof(SYSFS_GPIO_RST_DIR_VAL));

close(fd);

// 输出复位信号: 拉高>100ns

fd = open(SYSFS_GPIO_RST_VAL, O_RDWR);

if (fd == -1)

{

      printf("ERR: gpio open error.\n");

      return EXIT_FAILURE;

}

while (count)

{

      count--;

      printf("milk:%d\r\n",count);

      write(fd, SYSFS_GPIO_RST_VAL_H, sizeof(SYSFS_GPIO_RST_VAL_H));

      usleep(1000000);

      write(fd, SYSFS_GPIO_RST_VAL_L, sizeof(SYSFS_GPIO_RST_VAL_L));

      usleep(1000000);

}

close(fd);

// 打开端口/sys/class/gpio# echo 440 > unexport

fd = open(SYSFS_GPIO_UNEXPORT, O_WRONLY);

if (fd == -1)

{

      printf("ERR: unexport open error.\n");

      return EXIT_FAILURE;

}

write(fd, SYSFS_GPIO_RST_PIN_VAL, sizeof(SYSFS_GPIO_RST_PIN_VAL));

close(fd);

return 0;

}

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