// env/motor.zip
两个直流电机，控制前轮的用于转向
控制后轮的用于前进后退
编程，让用户方便的控制小车的运动
2.1 电机的驱动
硬件的接法：
电机上需要的瞬间电流可能是安培级的
而CPU上的管脚输出的电流是毫安级的
直流电机 步进电机 伺服电机
L298N芯片 有 15个引脚，可以驱动 两台直流电机
ENABLE A
INPUT 1/2
ENABLE B
INPUT 3/4
软件控制直流电机，就是控制L298N芯片
如何控制L298N？
M1正转：
ENABLEA 高
INPUT1 高
INPUT2 低
2.2 应用程序
gui_client:
5个按钮
点击按钮时给server 发不同的命令
开发板上的server
接收到命令
根据不同的命令
open
ioctl(...)
具体到小车 udp server 8000
30/31/32/33/34
// tcar_src.tar.gz/motor/app(应用) driver(驱动)
// 驱动代码基于S5PV210开发板编程的，非S5P6818
/* motor_drv.c - 基于S5PV210开发板连接的L298N芯片驱动 */#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <mach/gpio.h>
#include <asm/io.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include "motor_cmd.h"
#define TCAR_ENA S5PV210_GPH3(2)
#define TCAR_IN1 S5PV210_GPH2(2)
#define TCAR_IN2 S5PV210_GPH3(1)
#define TCAR_ENB S5PV210_GPH2(0)
#define TCAR_IN3 S5PV210_GPH2(1)
#define TCAR_IN4 S5PV210_GPH3(0)
typedef struct _tcar_gpios
{
unsigned int gpio_no;
const char *name;
}tcar_gpios_t;
tcar_gpios_t gpio_pins[] ={
{
.gpio_no = TCAR_ENA,
.name = "GPH3_2"
},
{
.gpio_no = TCAR_IN1,
.name = "GPH2_2"
},
{
.gpio_no = TCAR_IN2,
.name = "GPH3_1"
},
{
.gpio_no = TCAR_ENB,
.name = "GPH2_0"
},
{
.gpio_no = TCAR_IN3,
.name = "GPH2_1"
},
{
.gpio_no = TCAR_IN4,
.name = "GPH3_0"
},
};
struct timer_list tcar_timer;
void tcar_gpio_init(void)
{
int pins_num;
int i = 0;
pins_num = ARRAY_SIZE(gpio_pins);
for(; i<pins_num; i++)
{
gpio_request(gpio_pins[i].gpio_no, gpio_pins[i].name);
gpio_direction_output(gpio_pins[i].gpio_no, 0);
}
}
static void tcar_forward(void)
{
gpio_direction_output(gpio_pins[0].gpio_no,1);
gpio_direction_output(gpio_pins[1].gpio_no,1);
gpio_direction_output(gpio_pins[2].gpio_no,0);
}
static void tcar_backward(void)
{
gpio_direction_output(gpio_pins[0].gpio_no,1);
gpio_direction_output(gpio_pins[1].gpio_no,0);
gpio_direction_output(gpio_pins[2].gpio_no,1);
}
#define TCAR_TIMER 10
void tcar_timer_handler(unsigned long data)
{
gpio_direction_output(gpio_pins[3].gpio_no,1);
gpio_direction_output(gpio_pins[4].gpio_no,0);
gpio_direction_output(gpio_pins[5].gpio_no,0);
}
static void tcar_left(void)
{
gpio_direction_output(gpio_pins[3].gpio_no,1);
gpio_direction_output(gpio_pins[4].gpio_no,1);
gpio_direction_output(gpio_pins[5].gpio_no,0);
tcar_timer.expires = jiffies + TCAR_TIMER;
tcar_timer.function = tcar_timer_handler;
tcar_timer.data = 0;
add_timer(&tcar_timer);
}
static void tcar_right(void)
{
gpio_direction_output(gpio_pins[3].gpio_no,1);
gpio_direction_output(gpio_pins[4].gpio_no,0);
gpio_direction_output(gpio_pins[5].gpio_no,1);
tcar_timer.expires = jiffies + TCAR_TIMER;
tcar_timer.function = tcar_timer_handler;
tcar_timer.data = 0;
add_timer(&tcar_timer);
}
static void tcar_stop(void)
{
gpio_direction_output(gpio_pins[0].gpio_no,1);
gpio_direction_output(gpio_pins[1].gpio_no,0);
gpio_direction_output(gpio_pins[2].gpio_no,0);
gpio_direction_output(gpio_pins[3].gpio_no,1);
gpio_direction_output(gpio_pins[4].gpio_no,0);
gpio_direction_output(gpio_pins[5].gpio_no,0);
}
static int tcar_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long val)
{
switch (cmd)
{
case TCAR_FORWARD:
tcar_forward();
break;
case TCAR_BACKWARD:
tcar_backward();
break;
case TCAR_LEFT:
tcar_left();
break;
case TCAR_RIGHT:
tcar_right();
break;
case TCAR_STOP:
tcar_stop();
break;
default:
printk("invaild arg!\n");
break;
}
return 0;
}
static struct file_operations tcar_fops =
{
.owner = THIS_MODULE,
.ioctl = tcar_ioctl,
};
static struct miscdevice tcar_miscdev =
{
.minor = MISC_DYNAMIC_MINOR,
.name = "tcar",
.fops = &tcar_fops,
};
static int tcar_init(void)
{
/*申请使用的管脚*/
tcar_gpio_init();
misc_register(&tcar_miscdev);
/*初始化定时器*/
init_timer(&tcar_timer);
return 0;
}
static void tcar_exit(void)
{
int i = 0;
int pins_num = ARRAY_SIZE(gpio_pins);
del_timer(&tcar_timer);
misc_deregister(&tcar_miscdev);
for(; i<pins_num; i++)
{
gpio_free(gpio_pins[i].gpio_no);
}
}
module_init(tcar_init);
module_exit(tcar_exit);
MODULE_LICENSE("GPL");
/* udp_client.c */#include "tcar.h"#include "motor_cmd.h"int main(){ int sd = socket(PF_INET, SOCK_DGRAM, 0); struct sockaddr_in addr; addr.sin_family = PF_INET; addr.sin_port = htons(PORT); addr.sin_addr.s_addr = inet_addr("192.168.1.6"); int cmd = MOTOR_FORWARD; sendto(sd, &cmd, sizeof(cmd), 0, (struct sockaddr *)&addr, sizeof(addr)); getchar(); cmd = MOTOR_STOP; sendto(sd, &cmd, sizeof(cmd), 0, (struct sockaddr *)&addr, sizeof(addr)); getchar(); cmd = MOTOR_BACKWARD; sendto(sd, &cmd, sizeof(cmd), 0, (struct sockaddr *)&addr, sizeof(addr)); getchar(); cmd = MOTOR_STOP; sendto(sd, &cmd, sizeof(cmd), 0, (struct sockaddr *)&addr, sizeof(addr)); getchar(); cmd = MOTOR_LEFT; sendto(sd, &cmd, sizeof(cmd), 0, (struct sockaddr *)&addr, sizeof(addr)); getchar(); cmd = MOTOR_RIGHT; sendto(sd, &cmd, sizeof(cmd), 0, (struct sockaddr *)&addr, sizeof(addr)); getchar(); close(sd);}
/* udp_server.c */#include "tcar.h"#include "motor_cmd.h"int main(){ int fd = 0; static int to_down_up = 1500; static int to_right_left = 1500; int unit = 200; int sd = socket(PF_INET, SOCK_DGRAM, 0); struct sockaddr_in addr; addr.sin_family = PF_INET; addr.sin_port = htons(PORT); addr.sin_addr.s_addr = inet_addr("192.168.1.6"); bind(sd, (const struct sockaddr *)&addr, sizeof(addr)); while(1) { int cmd = 0; struct sockaddr_in fromaddr; int len = sizeof(fromaddr); recvfrom(sd, &cmd, sizeof(cmd), 0, (struct sockaddr *)&fromaddr, &len); switch(cmd) { case VIDEO_UP: to_down_up += unit; if(to_down_up >2500) { to_down_up = 2500; } fd = open("/dev/mg995", O_RDWR); ioctl(fd, IDEX0, to_down_up); close(fd); break; case VIDEO_DOWN: to_down_up -= unit; if(to_down_up < 500) { to_down_up = 500; } fd = open("/dev/mg995", O_RDWR); ioctl(fd, IDEX0, to_down_up); close(fd); break; case VIDEO_LEFT: to_right_left += unit; if(to_right_left >2500) { to_right_left = 2500; } fd = open("/dev/mg995", O_RDWR); ioctl(fd, IDEX1, to_right_left); close(fd); break; case VIDEO_RIGHT: to_right_left -= unit; if(to_right_left < 500) { to_right_left = 500; } fd = open("/dev/mg995", O_RDWR); ioctl(fd, IDEX1, to_right_left); close(fd); break; case MOTOR_FORWARD: fd = open("/dev/tcar", O_RDWR); ioctl(fd, TCAR_FORWARD); close(fd); break; case MOTOR_BACKWARD: fd = open("/dev/tcar", O_RDWR); ioctl(fd, TCAR_BACKWARD); close(fd); break; case MOTOR_LEFT: fd = open("/dev/tcar", O_RDWR); ioctl(fd, TCAR_LEFT); close(fd); break; case MOTOR_RIGHT: fd = open("/dev/tcar", O_RDWR); ioctl(fd, TCAR_RIGHT); close(fd); break; case MOTOR_STOP: fd = open("/dev/tcar", O_RDWR); ioctl(fd, TCAR_STOP); close(fd); break; default: break; } }}