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前言

本文采用开发板为STM32L475VET6(潘多拉开发板),使用RT_Thread Studio基于芯片开发模式，系统版本为4.0.3，完成模拟鼠标实验，实现鼠标功能，左键为KEY0，右键为KEY2

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一、板载资源

icm20608传感器采用I2C协议，本文采用软件模拟I2C
查阅数据手册：开发板使用的是 PC0 模拟时钟线SCL、PC1 模拟数据线 SDA，

二、具体步骤

1.配置icm20608传感器

RT-Thread+STM32L475VET6——icm20608传感器

2.打开CubeMX进行USB配置

生成工程

3. 配置USB

按照官方步骤配置

3.1 打开USB驱动

3.2 声明USB

3.3 剪切stm32xxxx_hal_msp.c中的void HAL_PCD_MspInit(PCD_HandleTypeDef* hpcd)和void HAL_PCD_MspDeInit(PCD_HandleTypeDef* hpcd)函数至board.c

3.4 使能USB

一般默认开启

4. 编译，烧录

示例代码

#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>#include "icm20608.h"
#include <math.h>#define DBG_SECTION_NAME "3D_mouse"
#define DBG_LEVEL DBG_LOG
#include <rtdbg.h>#define PIN_KEY0 GET_PIN(D,10)
#define PIN_KEY2 GET_PIN(D,8)static rt_sem_t mouse_sem = RT_NULL;static struct rt_thread usb_thread;
ALIGN(RT_ALIGN_SIZE)
static char usb_thread_stack[0x1000];static struct rt_thread icm_thread;
ALIGN(RT_ALIGN_SIZE)
static char icm_thread_stack[0x1000];static struct rt_thread key_thread;
ALIGN(RT_ALIGN_SIZE)
static char key_thread_stack[0x1000];/* 变动识别值 */
const static float mouse_rang_scope = 6.0f;
/* 读取角度有效角度 */
const static float mouse_angle_range = 80.0f;
/* 移动值的最大值 */
const static float mouse_move_range = 127.0f;
/* 角度移动比 */
#define mouse_ratio (mouse_move_range / mouse_angle_range)
/* 移动步长 */
const static rt_uint8_t mouse_pixel_len = 5;
/* 鼠标响应时间 */
const static rt_uint32_t mouse_sample_times = 0;static float mouse_cmp_last_x, mouse_cmp_last_y;#define Gyro_Gr 0.0010653f
#define pi 3.141593f
#define Kp 10.0f
#define Ki 0.008f
#define halfT 0.01fstatic float q0 = 1, q1 = 0, q2 = 0, q3 = 0;
static float exInt = 0, eyInt = 0, ezInt = 0;struct icm_position
{icm20608_device_t icm20608_device;rt_mutex_t lock;float x;           // 传感器 x 位置float y;           // 传感器 y 位置float z;           // 传感器 z 位置rt_int8_t buff[4]; // 发送鼠标的值
};
typedef struct icm_position *icm_position_t;icm_position_t icm_device = RT_NULL;static void mouse_meas_check(float *temp)
{if (*temp > mouse_angle_range){*temp = mouse_angle_range;}else if (*temp < -mouse_angle_range){*temp = -mouse_angle_range;}
}#ifdef __GNUC__const float __atan2f_lut[4] = {-0.0443265554792128, //p7-0.3258083974640975, //p3+0.1555786518463281, //p5+0.9997878412794807  //p1
};
const float __atan2f_pi_2 = 1.5707963;/* 求平方根 */
static float _sqrt(float x)
{float xhalf = 0.5f * x;int i = *(int *)&x;i = 0x5f375a86 - (i >> 1);x = *(float *)&i;x = x * (1.5f - xhalf * x * x);return 1.0 / x;
}/* 求绝对值 */
static float _fabs(float x)
{return (x >= 0 ? x : (-x));
}/* 求x / y的反正切值 */
static float _atan2f(float y, float x)
{float a, b, c, r, xx;int m;union {float f;int i;} xinv;xx = _fabs(x);xinv.f = xx;m = 0x3F800000 - (xinv.i & 0x7F800000);xinv.i = xinv.i + m;xinv.f = 1.41176471f - 0.47058824f * xinv.f;xinv.i = xinv.i + m;b = 2.0 - xinv.f * xx;xinv.f = xinv.f * b;b = 2.0 - xinv.f * xx;xinv.f = xinv.f * b;c = _fabs(y * xinv.f);xinv.f = c;m = 0x3F800000 - (xinv.i & 0x7F800000);xinv.i = xinv.i + m;xinv.f = 1.41176471f - 0.47058824f * xinv.f;xinv.i = xinv.i + m;b = 2.0 - xinv.f * c;xinv.f = xinv.f * b;b = 2.0 - xinv.f * c;xinv.f = xinv.f * b;xinv.f = xinv.f + c;a = (c > 1.0f);c = c - a * xinv.f;r = a * __atan2f_pi_2;xx = c * c;a = (__atan2f_lut[0] * c) * xx + (__atan2f_lut[2] * c);b = (__atan2f_lut[1] * c) * xx + (__atan2f_lut[3] * c);xx = xx * xx;r = r + a * xx;r = r + b;b = M_PI;b = b - 2.0f * r;r = r + (x < 0.0f) * b;b = (_fabs(x) < 0.000001f);c = !b;r = c * r;r = r + __atan2f_pi_2 * b;b = r + r;r = r - (y < 0.0f) * b;return r;
}static double _asin(double x)
{return _atan2f(x, _sqrt(1.0 - x * x));
}
#endif /* __GNUC__ *//* 获取俯仰角、偏航角、翻滚角 */
static void get_angle(icm_position_t dev, float ax, float ay, float az, float gx, float gy, float gz)
{float pitch = 0, roll = 0, yaw = 0;float norm;float vx, vy, vz;float ex, ey, ez;float q0q0 = q0 * q0;float q0q1 = q0 * q1;float q0q2 = q0 * q2;float q1q1 = q1 * q1;float q1q3 = q1 * q3;float q2q2 = q2 * q2;float q2q3 = q2 * q3;float q3q3 = q3 * q3;gx *= Gyro_Gr;gy *= Gyro_Gr;gz *= Gyro_Gr;if (az == 0)return;#ifdef __GNUC__norm = _sqrt(ax * ax + ay * ay + az * az);
#elsenorm = sqrt(ax * ax + ay * ay + az * az);
#endif /* __GNUC__ */ax = ax / norm;ay = ay / norm;az = az / norm;vx = 2 * (q1q3 - q0q2);vy = 2 * (q0q1 + q2q3);vz = q0q0 - q1q1 - q2q2 + q3q3;ex = (ay * vz - az * vy);ey = (az * vx - ax * vz);ez = (ax * vy - ay * vx);exInt = exInt + ex * Ki;eyInt = eyInt + ey * Ki;ezInt = ezInt + ez * Ki;gx = gx + Kp * ex + exInt;gy = gy + Kp * ey + eyInt;gz = gz + Kp * ez + ezInt;q0 = q0 + (-q1 * gx - q2 * gy - q3 * gz) * halfT;q1 = q1 + (q0 * gx + q2 * gz - q3 * gy) * halfT;q2 = q2 + (q0 * gy - q1 * gz + q3 * gx) * halfT;q3 = q3 + (q0 * gz + q1 * gy - q2 * gx) * halfT;#ifdef __GNUC__norm = _sqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3);
#elsenorm = sqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3);
#endif /* __GNUC__ */q0 = q0 / norm;q1 = q1 / norm;q2 = q2 / norm;q3 = q3 / norm;#ifdef __GNUC__pitch = -_asin(2 * (q0 * q2 - q1 * q3)) * 57.2957795f;roll = _asin(2 * (q0 * q1 + q2 * q3)) * 57.2957795f;yaw = -_atan2f(2 * (q1 * q2 + q0 * q3), (q0q0 + q1q1 - q2q2 - q3q3)) * 57.29578f;
#elsepitch = -asin(2 * (q0 * q2 - q1 * q3)) * 57.2957795f;roll = asin(2 * (q0 * q1 + q2 * q3)) * 57.2957795f;yaw = -atan2f(2 * (q1 * q2 + q0 * q3), (q0q0 + q1q1 - q2q2 - q3q3)) * 57.29578f;
#endif /* __GNUC__ */mouse_meas_check(&pitch);dev->x = pitch * mouse_ratio;mouse_meas_check(&roll);dev->y = roll * mouse_ratio;mouse_meas_check(&yaw);dev->z = yaw * mouse_ratio;
}static void mouse_get_pos(icm_position_t dev)
{rt_err_t result;rt_int16_t accel_x, accel_y, accel_z;rt_int16_t gyros_x, gyros_y, gyros_z;RT_ASSERT(dev);result = rt_mutex_take(dev->lock, RT_WAITING_FOREVER);if (result != RT_EOK){goto __exit;}result = icm20608_get_accel(dev->icm20608_device, &accel_x, &accel_y, &accel_z);if (result != RT_EOK){rt_mutex_release(dev->lock);goto __exit;}result = icm20608_get_gyro(dev->icm20608_device, &gyros_x, &gyros_y, &gyros_z);if (result != RT_EOK){rt_mutex_release(dev->lock);goto __exit;}get_angle(dev, (float)accel_x, (float)accel_y, (float)accel_z, (float)gyros_x, (float)gyros_y, (float)gyros_z);rt_mutex_release(dev->lock);__exit:if (result != RT_EOK){LOG_E("The sensor does not work");return;}
}static icm_position_t mouse_init_icm(void)
{rt_err_t result;rt_thread_mdelay(1000);icm_device = rt_calloc(1, sizeof(struct icm_position));if (icm_device == RT_NULL){LOG_E("Can't allocate memory for three-dimensional mouse ");return RT_NULL;}/* 初始化传感器 icm20608 */icm_device->icm20608_device = icm20608_init("i2c3");if (icm_device->icm20608_device == RT_NULL){LOG_E("The sensor initializes failure");rt_free(icm_device);return RT_NULL;}else{LOG_D("The 3D mouse initializes success");}icm_device->lock = rt_mutex_create("mutex_mouse", RT_IPC_FLAG_FIFO);if (icm_device->lock == RT_NULL){LOG_E("Can't create mutex for three-dimensional mouse");rt_free(icm_device);return RT_NULL;}mouse_sem = rt_sem_create("mouse_sem", 0, RT_IPC_FLAG_FIFO);if (mouse_sem == RT_NULL){LOG_E("Can't create sem for mouse device");rt_mutex_delete(icm_device->lock);rt_free(icm_device);return 0;}/* 传感器零值校准 */result = icm20608_calib_level(icm_device->icm20608_device, 10);if (result != RT_EOK){LOG_E("The sensor calibrates failure");rt_mutex_delete(icm_device->lock);rt_sem_delete(mouse_sem);rt_free(icm_device);return RT_NULL;}return icm_device;
}static void mouse_go_release_status(void)
{/* 初始状态值 */rt_int8_t buff[4] = {0x08, 0, 0, 0};icm_device->buff[0] = buff[0];icm_device->buff[1] = buff[1];icm_device->buff[2] = buff[2];icm_device->buff[3] = buff[3];
}static void mouse_send_data(rt_device_t device)
{RT_ASSERT(device != RT_NULL);rt_device_write(device, HID_REPORT_ID_MOUSE, icm_device->buff, 4);mouse_go_release_status();
}/* 负值表示向左移动，正值表示向右移动 */
static void mouse_move_x(rt_device_t device, float ratio_x)
{RT_ASSERT(device != RT_NULL);if (icm_device->x < 0){icm_device->buff[1] = (rt_int8_t)(-mouse_pixel_len * ratio_x);}else{icm_device->buff[1] = (rt_int8_t)(mouse_pixel_len * ratio_x);}mouse_send_data(device);
}/* 正值表示向下移动，负值表示向上移动 */
static void mouse_move_y(rt_device_t device, float ratio_y)
{RT_ASSERT(device != RT_NULL);if (icm_device->y < 0){icm_device->buff[2] = (rt_int8_t)(-mouse_pixel_len * ratio_y);}else{icm_device->buff[2] = (rt_int8_t)(mouse_pixel_len * ratio_y);}mouse_send_data(device);
}static void mouse_move_xy(rt_device_t device, float ratio_x, float ratio_y)
{RT_ASSERT(device != RT_NULL);if (icm_device->x < 0){icm_device->buff[1] = (rt_int8_t)(-mouse_pixel_len * ratio_x);}else{icm_device->buff[1] = (rt_int8_t)(mouse_pixel_len * ratio_x);}if (icm_device->y < 0){icm_device->buff[2] = (rt_int8_t)(-mouse_pixel_len * ratio_y);}else{icm_device->buff[2] = (rt_int8_t)(mouse_pixel_len * ratio_y);}mouse_send_data(device);
}static void usb_thread_entry(void *parameter)
{rt_device_t device = (rt_device_t)parameter;rt_uint8_t i = 0;while (1){if (rt_sem_take(mouse_sem, RT_WAITING_FOREVER) == RT_EOK){rt_uint8_t temp_x = 0, temp_y = 0, move_max = 0;float move_distance = 0.0f;rt_mutex_take(icm_device->lock, RT_WAITING_FOREVER);#ifdef __GNUC__temp_x = (rt_uint8_t)_fabs(icm_device->x);temp_y = (rt_uint8_t)_fabs(icm_device->y);move_distance = _sqrt(temp_x * temp_x + temp_y * temp_y);
#elsetemp_x = (rt_uint8_t)fabs(icm_device->x);temp_y = (rt_uint8_t)fabs(icm_device->y);move_distance = sqrt(temp_x * temp_x + temp_y * temp_y);
#endifmove_max = temp_x > temp_y ? temp_x : temp_y;/* 根据倾斜程度获取移动值 */for (i = 0; i < move_max / mouse_pixel_len; i++){LOG_D("move_max :%4d, x: %4d, y :%4d ", move_max, temp_x, temp_y);if (i < temp_x && i < temp_y){mouse_move_xy(device, temp_x / move_distance, temp_y / move_distance);}else if (i < temp_x && i >= temp_y){mouse_move_x(device, temp_x / move_distance);}else if (i >= temp_x && i < temp_y){mouse_move_y(device, temp_y / move_distance);}else{break;}}rt_mutex_release(icm_device->lock);}rt_thread_mdelay(mouse_sample_times);}
}static void icm_thread_entry(void *parameter)
{while (1){float temp_x = 0.0, temp_y = 0.0;rt_mutex_take(icm_device->lock, RT_WAITING_FOREVER);/* 获取鼠标移动范围 */mouse_get_pos(icm_device);/* 获取差值 */temp_x = icm_device->x - mouse_cmp_last_x;temp_y = icm_device->y - mouse_cmp_last_y;/* 避免抖动 */if (temp_x > mouse_rang_scope || temp_x < -mouse_rang_scope || temp_y > mouse_rang_scope || temp_y < -mouse_rang_scope){/* 存储这次鼠标位移值 */mouse_cmp_last_x = icm_device->x;mouse_cmp_last_y = icm_device->y;rt_sem_release(mouse_sem);}rt_mutex_release(icm_device->lock);rt_thread_mdelay(mouse_sample_times);}
}static void key_thread_entry(void *parameter)
{int mouse_key_2, mouse_key_0;rt_device_t device = (rt_device_t)parameter;rt_err_t result = -RT_ERROR;while (1){if (rt_pin_read(PIN_KEY0) == PIN_LOW){mouse_key_0 = 1;}else if (rt_pin_read(PIN_KEY2) == PIN_LOW){mouse_key_2 = 1;}else{mouse_key_2 = 0;mouse_key_0 = 0;}if (mouse_key_2 | mouse_key_0){result = rt_mutex_take(icm_device->lock, RT_WAITING_FOREVER);if (result == RT_EOK){/* 获取鼠标键值，默认为 0 */icm_device->buff[0] = 0x08 | mouse_key_2 | mouse_key_0 << 1;if (mouse_key_2 & mouse_key_0){LOG_D("left & right down");}else if (mouse_key_2){LOG_D("left down");}else if (mouse_key_0){LOG_D("right down");}mouse_send_data(device);rt_mutex_release(icm_device->lock);rt_thread_mdelay(50);}}rt_thread_mdelay(mouse_sample_times / 5);}
}static void mouse_init_key(void)
{/* 鼠标左键 */rt_pin_mode(PIN_KEY0, PIN_MODE_INPUT);/* 鼠标右键 */rt_pin_mode(PIN_KEY2, PIN_MODE_INPUT);
}int main(void)
{return 0;
}static int application_usb_init(void)
{/* 查找名称为 hidd 的设备 */rt_device_t device = rt_device_find("hidd");/* 初始化六轴传感器设备 */icm_device = mouse_init_icm();/* 初始化按键 */mouse_init_key();RT_ASSERT(device != RT_NULL);RT_ASSERT(icm_device != RT_NULL);/*打开查找到的 hid 设备 */rt_device_open(device, RT_DEVICE_FLAG_WRONLY);/* 初始化 USB 线程*/rt_thread_init(&usb_thread,"hidd",usb_thread_entry, device,usb_thread_stack, sizeof(usb_thread_stack),10, 20);rt_thread_startup(&usb_thread);/* 初始化六轴传感器线程 */rt_thread_init(&icm_thread,"icm20608",icm_thread_entry, RT_NULL,icm_thread_stack, sizeof(icm_thread_stack),10, 20);rt_thread_startup(&icm_thread);/* 初始化按键线程 */rt_thread_init(&key_thread,"key",key_thread_entry, device,key_thread_stack, sizeof(key_thread_stack),10, 20);rt_thread_startup(&key_thread);return 0;
}
INIT_APP_EXPORT(application_usb_init);

烧录完成后，将开发板上的USB OTG 连接PC端的USB接口，即可实现鼠标功能。

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