项目上使用了一款Lis2dh12三轴加速度传感器。
要引用官方提供SDK中的lis2dh12_reg.h文件、lis2dh12_reg.c文件，才行。
我使用的主控芯片是STM32L051C8T6，硬件IIC与lis2dh12通讯。
原理图：
1、创建lis2dh12.c文件
#include "lis2dh12.h"
#include "lis2dh12_reg.h"
#include "i2c.h"
#include "stdlib.h"
#include "stdio.h"
#include <string.h>
#include <math.h>
#define LIS2DH12_FROM_FS_2g_HR_TO_mg(lsb) (float)((int16_t)lsb>>4) * 1.0f
#define LIS2DH12_FROM_FS_4g_HR_TO_mg(lsb) (float)((int16_t)lsb>>4) * 2.0f
#define LIS2DH12_FROM_FS_8g_HR_TO_mg(lsb) (float)((int16_t)lsb>>4) * 4.0f
#define LIS2DH12_FROM_FS_16g_HR_TO_mg(lsb) (float)((int16_t)lsb>>4) * 12.0f
#define LIS2DH12_FROM_LSB_TO_degC_HR(lsb) (float)((int16_t)lsb>>6) / 4.0f+25.0f
axis_info_t acc_sample;
filter_avg_t acc_data;
/* ============================================================
func name : lis2_Delay_us
discription : lis2 微妙延时
param : us
return :
Revision :
=============================================================== */
void lis2_Delay_us(uint32_t us)
{
int n = 11;
while(--us)
{
while(--n);
n = 11;
}
}
/* ============================================================
func name : lis2_Delay_ms
discription : lis2 毫秒延时
param : ms
return :
Revision :
=============================================================== */
void lis2_Delay_ms(uint32_t ms)
{
int i = 0;
for(;i<ms;i++)
{
lis2_Delay_us(1000);
}
}
/* ============================================================
func name : lis2dh12_iic_read_byte
discription : 写一个字节
param : reg:寄存器地址，data:寄存器对应的值
return :
Revision :
=============================================================== */
int32_t lis2dh12_iic_write_byte(uint8_t reg, uint8_t data)
{
#ifdef HARDWARE_IIC
HAL_I2C_Mem_Write(&hi2c1, LIS2DH12_I2C_ADD_H, reg,I2C_MEMADD_SIZE_8BIT, &data, 1, 1000);
#endif
#ifdef SIMULATED_IIC
Lis2DH12_IIC_Write_Byte(LIS2DH12_I2C_ADD_H, reg, data);
#endif
return 1;
}
/* ============================================================
func name : lis2dh12_iic_read_byte
discription : 读一个字节
param : reg:寄存器地址，data:寄存器对应的值
return :
Revision :
=============================================================== */
int32_t lis2dh12_iic_read_byte(uint8_t reg, uint8_t* data)
{
#ifdef HARDWARE_IIC
HAL_I2C_Mem_Read(&hi2c1, LIS2DH12_I2C_ADD_H, reg,I2C_MEMADD_SIZE_8BIT, data, 1, 1000);
#endif
#ifdef SIMULATED_IIC
Lis2DH12_IIC_Read_Byte(LIS2DH12_I2C_ADD_H, reg, data);
#endif
return 1;
}
/* ============================================================
func name : Lis2dh12_Init
discription : 配置检测阈值与中断
param : void
return :
Revision :
=============================================================== */
int32_t Lis2dh12_Init(void)
{
/* Initialization of sensor */
lis2dh12_iic_write_byte(0x20, 0x37); /* CTRL_REG1(20h): 关闭sensor，设置进入掉电模式 ODR 25HZ */
// lis2dh12_iic_write_byte(0x20, 0x57); /* CTRL_REG1(20h): 关闭sensor，设置进入低功耗模式 ODR 100HZ */
lis2dh12_iic_write_byte(0x21, 0x03); /* CTRL_REG2(21h): IA1、IA2 开启高通滤波 bc */
lis2dh12_iic_write_byte(0x22, 0xc0); /* CTRL_REG3(22h): 0x80 使能单击中断到INT_1 INT_2 */
lis2dh12_iic_write_byte(0x23, 0x88); /* CTRL_REG4(23h): 使能快，数据更新，全量程+/-2G，非常精度模式 */
// lis2dh12_iic_write_byte(0x25, 0x00); /* CTRL_REG6(25h): 高电平(上升沿)触发中断 */
/* INT1 翻转检测，中断*/ //0x6a
lis2dh12_iic_write_byte(0x30, 0x7f); /* INT1_CFG(30h): 使能，6D X/Y/Z任一超过阈值中断 */
// lis2dh12_iic_write_byte(0x30, 0x4f); /* INT1_CFG(30h): 使能，6D X/Y任一超过阈值中断 */
// lis2dh12_iic_write_byte(0x31, 0x20); /* INT1_SRC(31h): 设置中断源 */
lis2dh12_iic_write_byte(0x32, 0x02); /* INT1_THS(32h): 设置中断阀值 0x10: 16*2(FS) 0x20: 32*16(FS) */
// lis2dh12_iic_write_byte(0x33, 0x02); /* INT1_DURATION(33h): 1LSB=1/ODR 如果ODR=25HZ 那么1LSB=40ms 设置延时 1s,对应25->0x19 */
// lis2dh12_iic_write_byte(0x33, 0x03); /* INT1_DURATION(33h): 1LSB=1/ODR 如果ODR=50HZ 那么1LSB=20ms 设置延时 1s,对应50->0x32 */
lis2dh12_iic_write_byte(0x33, 0x03); /* INT1_DURATION(33h): 1LSB=1/ODR 如果ODR=100HZ 那么1LSB=10ms 设置延时 1s,对应100->0x64 */
// /* INT2 单击中断 */
//// lis2dh12_iic_write_byte(0x24, 0x01); /* CTRL_REG5(24h): */
// lis2dh12_iic_write_byte(0x25, 0xa0); /* CTRL_REG6(25h): Click interrupt on INT2 pin */
//
// lis2dh12_iic_write_byte(0x38, 0x15); /* CLICK_CFG (38h): 单击识别中断使能 */
//// lis2dh12_iic_write_byte(0x39, 0x10);
// lis2dh12_iic_write_byte(0x3a, 0x7f); /* CLICK_THS (3Ah): 单击阀值 */
// lis2dh12_iic_write_byte(0x3b, 0xff); /* TIME_LIMIT (3Bh): 时间限制窗口6 ODR 1LSB=1/ODR 1LSB=1/100HZ,10ms,设置延时1s,对应100—>0x64*/
// lis2dh12_iic_write_byte(0x3c, 0xff); /* TIME_LATENCY (3Ch): 中断电平持续时间1 ODR=10ms */
// lis2dh12_iic_write_byte(0x3d, 0x01); /* TIME_WINDOW (3Dh): 单击时间窗口 */
/* Start sensor */
// lis2dh12_iic_write_byte(0x20, 0x37);
lis2dh12_iic_write_byte(0x20, 0x5f); /* CTRL_REG1(20h): Start sensor at ODR 100Hz Low-power mode */
return 0;
}
/* ============================================================
func name : get_acc_value
discription : 获取加速度值
param : axis_info_t *sample
return : void
Revision :
=============================================================== */
void get_acc_value(axis_info_t *sample)
{
uint8_t i = 0,j = 0;
uint8_t data[6];
for (i=0; i<6; i++){
lis2dh12_iic_read_byte(0x28+i, data+i); //获取X、y、z轴的数据
//printf("data[i] %d, \r\n", data[i]);
}
// sample->x = abs((int)(LIS2DH12_FROM_FS_2g_HR_TO_mg(*(int16_t*)data)));
// sample->y = abs((int)(LIS2DH12_FROM_FS_2g_HR_TO_mg(*(int16_t*)(data+2))));
// sample->z = abs((int)(LIS2DH12_FROM_FS_2g_HR_TO_mg(*(int16_t*)(data+4))));
sample->x = LIS2DH12_FROM_FS_2g_HR_TO_mg(*(int16_t*)data);
sample->y = LIS2DH12_FROM_FS_2g_HR_TO_mg(*(int16_t*)(data+2));
sample->z = LIS2DH12_FROM_FS_2g_HR_TO_mg(*(int16_t*)(data+4));
}
/* ============================================================
func name : filter_calculate
discription : 均值滤波器---滤波
读取xyz数据存入均值滤波器，存满进行计算，滤波后样本存入sample
param : filter_avg_t *filter, axis_info_t *sample
return : void
Revision :
=============================================================== */
static void filter_calculate(filter_avg_t *filter, axis_info_t *sample)
{
uint8_t i = 0;
short x_sum = 0, y_sum = 0, z_sum = 0;
for (i=0; i<FILTER_CNT; i++)
{
get_acc_value(sample);
filter->info[i].x = sample->x;
filter->info[i].y = sample->y;
filter->info[i].z = sample->z;
x_sum += filter->info[i].x;
y_sum += filter->info[i].y;
z_sum += filter->info[i].z;
printf("acc_x:%d, acc_y:%d, acc_z:%d \n",filter->info[i].x,filter->info[i].y,filter->info[i].z);
}
sample->x = x_sum / FILTER_CNT;
sample->y = y_sum / FILTER_CNT;
sample->z = z_sum / FILTER_CNT;
printf("\r\n acc_info.acc_x:%d, acc_info.acc_y:%d, acc_info.acc_z:%d \r\n",sample->x, sample->y, sample->z);
}
/* ============================================================
func name : new_angle_calculate
discription : 计算新角度
param : axis_info_t *sample
return : void
Revision :
=============================================================== */
static void new_angle_calculate(axis_info_t *sample)
{
sample->new_angle_x = atan((short)sample->x/(short)sqrt(pow(sample->y, 2)+pow(sample->z, 2))) * DEGREE_CAL;
sample->new_angle_y = atan((short)sample->y/(short)sqrt(pow(sample->x, 2)+pow(sample->z, 2))) * DEGREE_CAL;
sample->new_angle_z = atan((short)sample->z/(short)sqrt(pow(sample->x, 2)+pow(sample->y, 2))) * DEGREE_CAL;
if (sample->new_angle_z < 0)
{
sample->new_angle_x = 180-sample->new_angle_x;
sample->new_angle_y = 180-sample->new_angle_y;
}
printf("sample->new_angle_x:%d, sample->new_angle_y:%d, sample->new_angle_z:%d \r\n",sample->new_angle_x, sample->new_angle_y, sample->new_angle_z);
}
/* ============================================================
func name : old_angle_calculate
discription : 计算旧角度
param : axis_info_t *sample
return : void
Revision :
=============================================================== */
static void old_angle_calculate(axis_info_t *sample)
{
sample->old_angle_x = atan((short)sample->x/(short)sqrt(pow(sample->y, 2)+pow(sample->z, 2))) * DEGREE_CAL;
sample->old_angle_y = atan((short)sample->y/(short)sqrt(pow(sample->x, 2)+pow(sample->z, 2))) * DEGREE_CAL;
sample->old_angle_z = atan((short)sample->z/(short)sqrt(pow(sample->x, 2)+pow(sample->y, 2))) * DEGREE_CAL;
if (sample->old_angle_z < 0)
{
sample->old_angle_x = 180-sample->old_angle_x;
sample->old_angle_y = 180-sample->old_angle_y;
}
printf("sample->old_angle_x:%d, sample->old_angle_y:%d, sample->old_angle_z:%d \r\n",sample->old_angle_x, sample->old_angle_y, sample->old_angle_z);
}
在此重点说明，如果想调传感器的中断灵敏度，注意：关注1、INT1_THS(32h)，2、INT1_DURATION(33h)这两个寄存器即可。
INT1_THS(32h)
计算阀值：主要是看配置中断的量程是哪个。
（1）如果量程 FS=2g 每1LSB=16mg
那么寄存器配置INT1_THS=2 那么阈值=2*16mg
如果INT1_THS=5 那么阈值=5*16mg
（2）如果量程FS=4g，那么每1LSB=32mg
INT1_THS =5 阈值就是5*32mg=160mg
看配置的ODR是哪个，来计算延时的时间。
1LSB=1/ODR 如果ODR=50HZ 那么1LSB=20ms
/*
500mg = 30°
250mg = 15°
160mg = 10°
我现在对应的量程是FS=2g，INT1_THS=10，那么阀值=10*16mg
1LSB=1/ODR 如果ODR=50HZ 那么1LSB=20ms
50LSB = 1s
100LSB = 2s
*/2、创建lis2dh12.h文件
#ifndef __LIS2DH12_H
#define __LIS2DH12_H
#ifdef __cplusplus
extern "C"
{
#endif
#include "stdint.h"
#define DEGREE_CAL 180.0/3.1416
typedef struct {
short x;
short y;
short z;
short new_angle_x;
short new_angle_y;
short new_angle_z;
short old_angle_x;
short old_angle_y;
short old_angle_z;
}axis_info_t;
typedef struct filter_avg{
axis_info_t info[FILTER_CNT];
unsigned char count;
}filter_avg_t;
#endifmain.c文件
int main(void)
{
filter_calculate(&acc_data, &acc_sample);
old_angle_calculate(&acc_sample);
while(1)
{
HAL_Delay(1000);
filter_calculate(&acc_data, &acc_sample);
new_angle_calculate(&acc_sample);
}
}远行结果如下：
