2022.0306避障小车学习1
要求：使用stm32f103单片机，应用RTOS实时系统，使用超声波模块，oled屏，l298n直流步进电机 驱动模块和小车底盘。
思路：在任务里用超声波实时测出距障碍物的距离，并将距离显示在oled屏上，再根据判断距离大小调用前进或者后退那些函数。
1.oled屏：显示距离，频率等数据
怎么显示。。。
2.超声波测距
float Measure()
{
struct timeval t1; //超声波测距结构体，系统自带
struct timeval t2;
long start; // 刚开始接受信号
long end; // 最后接受信号
float distance;
digitalWrite(Trig,LOW); // 让超声波一开始信号平稳
delayMicroseconds(2);
digitalWrite(Trig,HIGH); //发出超声波脉冲，开始测距
delayMicroseconds(10);
digitalWrite(Trig,LOW);
// 直到发送完信号，开始计时
while(!(digitalRead(Echo) == 1) ); //获取当前时间，最开始接受到返回信号的时间
gettimeofday(&t1,NULL);
// 信号回来完毕，结束计时，否则阻塞等待
while(!(digitalRead(Echo) == 0) ); //获取当前时间，最后接受到返回信号的时间
gettimeofday(&t2,NULL);
start = t1.tv_sec*1000000 + t1.tv_usec;
end = t2.tv_sec*1000000 + t2.tv_usec;
// 空气中传播 340 m/s
distance = (float)(end - start) / 1000000 * 34000 / 2; //测出信号往返距离
return distance;
}
这个函数返回信号往返距离，然后判断1/2距离调整怎么小车怎么转。
参考：(40条消息) 超声波测距原理、代码实现_正弦定理的博客-CSDN博客
3.控制前进后退函数：
//占空比=50%的情况
/* USER CODE BEGIN PV */
uint8_t velocity = 50;
/* USER CODE END PV */在main中开启pwm
/* USER CODE BEGIN 2 */
HAL_TIM_PWM_Start(&htim3,TIM_CHANNEL_2);
HAL_TIM_PWM_Start(&htim4,TIM_CHANNEL_1);
HAL_TIM_PWM_Start(&htim4,TIM_CHANNEL_2);
HAL_TIM_PWM_Start(&htim4,TIM_CHANNEL_3);
HAL_TIM_PWM_Start(&htim2,TIM_CHANNEL_2);
HAL_TIM_PWM_Start(&htim2,TIM_CHANNEL_3);
HAL_TIM_PWM_Start(&htim2,TIM_CHANNEL_4);
HAL_TIM_PWM_Start(&htim3,TIM_CHANNEL_3);
/* USER CODE END 2 */void Reset()
{
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_2,0);
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3,0);
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_2,0);
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_1,0);
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_2,0);
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_3,0);
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_4,0);
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_3,0);//后轮
}
void forward()
{
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_2,0);//前右倒转 该通道的占空比为零
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3,velocity);//前右正转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_2,0);//前左倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_1,velocity);//前左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_2,0);//后左倒转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_3,velocity);//后左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_4,0);//后右倒转
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_3,velocity);//后右正转
}
void backward()
{
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_2,velocity);//前右倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3,0);//前右正转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_2,velocity);//前左倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_1,0);//前左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_2,velocity);//后左倒转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_3,0);//后左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_4,velocity);//后右倒转
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_3,0);//后右正转
}
void shift_left()
{
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_2,0);//前右倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3,0);//前左正转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_2,velocity);//前左倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_1,velocity);//前右正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_2,0);//后左倒转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_3,velocity);//后左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_4,velocity);//后右倒转
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_3,0);//后右正转
}
void shift_right()
{
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_2,velocity);//前右倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3,velocity);//前左正转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_2,0);//前左倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_1,0);//前右正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_2,velocity);//后左倒转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_3,0);//后左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_4,0);//后右倒转
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_3,velocity);//后右正转
}
void turn_left()
{
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_2,0);//前右倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3,0);//前左正转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_2,velocity);//前左倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_1,velocity);//前右正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_2,velocity);//后左倒转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_3,0);//后左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_4,0);//后右倒转
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_3,velocity);//后右正转
}
void turn_right()
{
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_2,velocity);//前右倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3,velocity);//前左正转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_2,0);//前左倒转
__HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_1,0);//前右正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_2,0);//后左倒转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_3,velocity);//后左正转
__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_4,velocity);//后右倒转
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_3,0);//后右正转
}