飞凌嵌入式ElfBoard ELF 1板卡-运动追踪之编写程序

编程步骤

（一）打开设备

#define ICM20607_DEV "/dev/icm20607"




        fd = open(ICM20607_DEV, O_RDWR);

        if(fd < 0) {

                printf("can't open file %srn", ICM20607_DEV);

                return -1;

        }

宏定义板卡上的传感器节点为/dev/icm20607；

使用open()打开传感器，如果错误返回-1；

（二）读取数据

ret = read(fd, databuf, sizeof(databuf));

使用read将设备中的数据读取出来放入datebuf中。

（三）定义数组成员

gyro_x_adc = databuf[0];

gyro_y_adc = databuf[1];

gyro_z_adc = databuf[2];

accel_x_adc = databuf[3];

accel_y_adc = databuf[4];

accel_z_adc = databuf[5];

temp_adc = databuf[6];

把x、y、z轴的角速度，x、y、z轴的加速度和温度一共7个元素填入数组内，这些成员是从设备中读取出来的数据。

（四）数据类型转换

gyro_x_act = (float)(gyro_x_adc)  / 16.4;

gyro_y_act = (float)(gyro_y_adc)  / 16.4;

gyro_z_act = (float)(gyro_z_adc)  / 16.4;

accel_x_act = (float)(accel_x_adc) / 2048;

accel_y_act = (float)(accel_y_adc) / 2048;

accel_z_act = (float)(accel_z_adc) / 2048;

temp_act = ((float)(temp_adc) - 25 ) / 326.8 + 25;

因为角速度、加速度和温度这些都不能用常量表示，所以需要给他们转换成浮点量，并做相应数学计算，以转换成我们可读的数据。

（五）关闭设备

close(fd);

详细代码

elf1_cmd_icm20607：

#include "stdio.h"

#include "unistd.h"

#include "sys/types.h"

#include "sys/stat.h"

#include "sys/ioctl.h"

#include "fcntl.h"

#include "stdlib.h"

#include "string.h"

#include <poll.h>

#include <sys/select.h>

#include <sys/time.h>

#include <signal.h>

#include <fcntl.h>




#define ICM20607_DEV "/dev/icm20607"




int main(int argc, char *argv[])

{

int fd;

signed int databuf[7];

unsigned char data[14];

signed int gyro_x_adc, gyro_y_adc, gyro_z_adc;

signed int accel_x_adc, accel_y_adc, accel_z_adc;

signed int temp_adc;




float gyro_x_act, gyro_y_act, gyro_z_act;

float accel_x_act, accel_y_act, accel_z_act;

float temp_act;




int ret = 0;




fd = open(ICM20607_DEV, O_RDWR);

if(fd < 0) {

printf("can't open file %srn", ICM20607_DEV);

return -1;

}




while (1) {

ret = read(fd, databuf, sizeof(databuf));

if(ret == 0) { /* ?????? */

gyro_x_adc = databuf[0];

gyro_y_adc = databuf[1];

gyro_z_adc = databuf[2];

accel_x_adc = databuf[3];

accel_y_adc = databuf[4];

accel_z_adc = databuf[5];

temp_adc = databuf[6];




/* ????? */

gyro_x_act = (float)(gyro_x_adc)  / 16.4;

gyro_y_act = (float)(gyro_y_adc)  / 16.4;

gyro_z_act = (float)(gyro_z_adc)  / 16.4;

accel_x_act = (float)(accel_x_adc) / 2048;

accel_y_act = (float)(accel_y_adc) / 2048;

accel_z_act = (float)(accel_z_adc) / 2048;

temp_act = ((float)(temp_adc) - 25 ) / 326.8 + 25;







printf("rn");

printf("raw value:rn");

printf("gx = %d, gy = %d, gz = %drn", gyro_x_adc, gyro_y_adc, gyro_z_adc);

printf("ax = %d, ay = %d, az = %drn", accel_x_adc, accel_y_adc, accel_z_adc);

printf("temp = %drn", temp_adc);




printf("rn");

printf("act value:rn");

printf("act gx = %.2f度/S, act gy = %.2f度/S, act gz = %.2f度/Srn", gyro_x_act, gyro_y_act, gyro_z_act);

printf("act ax = %.2fg, act ay = %.2fg, act az = %.2fgrn", accel_x_act, accel_y_act, accel_z_act);

printf("act temp = %.2f摄氏度rn", temp_act);

}

sleep(1); /*1s */

}

close(fd);

return 0;

}