【Milk-V Duo 开发板免费体验】2、C语言交叉编译控制LED

[Raphta]

C语言交叉编译控制LED

---

参考教程：https://spotpear.cn/index/study/detail/id/1137.html

1、进入milkv，cat /proc/version

---

官方使用riscv64-unknown-linux-musl-gcc编译器，个人编译时也需要使用相同编译器。

2、为方便管理，在SDK下创建test文件夹，编写led.c,

---

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h> //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;
}

3、在电脑ubuntu查找对应的编译器

---

sudo find / | grep riscv64-unknown-linux-musl-gcc

4、编译生成可执行文件

---

sudo /home/ffd8/duo-buildroot-sdk-develop/host-tools/gcc/riscv64-linux-musl-x86_64/bin/riscv64-unknown-linux-musl-gcc -static -o led led.c

5、传输到Duo开发板

---

sudo scp ./led root@192.168.42.1:/root/

6、运行程序

---

程序按照预期打印了30次，同时板载蓝灯同步闪烁

本文转载自：https://bbs.elecfans.com/jishu_2369118_1_1.html，作者：FFD80