/******************** *******************************************************
* 文件名 : UltrasonicWave.c
* 描述 ：超聲波測距模塊，
初始化 Ultrasonic_Init()
UltrasonicWave_StartMeasure 發送超聲波啟動
返回中斷Echo中得到高電平時間，從而獲取距離
exti ISR 中調ultrasonic_calculate（）；
注意本模塊使用到timer2
*********************************************************************************/
struct UltrasonicDefine U_GPIO_Define;
volatile uint16_t ultrasonic_wave_measure_data;
/*************************************************************
Function ：Ultrasonic_Config
Description：超聲波的引腳配置
Input : UltrasonicDefine類型源參數
return : none
*************************************************************/
void ultrasonic_configuratioin(struct UltrasonicDefine defines)
{
struct UltrasonicDefine def = defines;
GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
U_GPIO_Define = defines;
GPIO_InitStructure.GPIO_Pin = def.pin_of_trig;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;
GPIO_Init(def.pin_of_trig_group, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = def.pin_of_echo;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_Init(def.pin_of_echo_group, &GPIO_InitStructure);
SYSCFG_EXTILineConfig(def.gpio_portsource, def.gpio_pinsource);
EXTI_InitStructure.EXTI_Line = def.exit_line_no;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = def.irqn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/*************************************************************
Function ：Timer2_Init
Description：通用定時器中斷初始化 這里使用的是TIM2 系統時鐘system_sclk是16MHZ
Input : arr：自動重裝值。 psc：時鐘預分頻數
return : none
*************************************************************/
static void timer2_init(uint16_t arr,uint16_t psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructure.TIM_Period = arr; //設置在下一個更新事件裝入活動的自動重裝載寄存器周期的值 計數到5000為500ms
TIM_TimeBaseStructure.TIM_Prescaler = (psc-1); //設置用來作為TIMx時鐘頻率除數的預分頻值 10Khz的計數頻率
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //設置時鐘分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數模式
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
}
/*************************************************************
Function ：Ultrasonic_Init
Description：初始化 Ultrasonic Module Pins以及記錄高電平（返回信號）時間的timer 初始化
Input : none
return : none
*************************************************************/
void ultrasonic_init(void)
{
timer2_init(5000, 3200); //500ms for sysclk = 32MHz
}
/*************************************************************
Function ：UltrasonicWave_StartMeasure
Description：發送一個大于10us的高電平
|--------|
------| |------ > 10us
Input : none
return : none
*************************************************************/
void ultrasonicWave_startMeasure(void)
{
GPIO_SetBits(U_GPIO_Define.pin_of_trig_group,U_GPIO_Define.pin_of_trig); //送>10US的高電平
Delay_nus(15); //延時15US
GPIO_ResetBits(U_GPIO_Define.pin_of_trig_group,U_GPIO_Define.pin_of_trig);
}
/*************************************************************
Function ：Ultrasonic_GetData
Description：統計返回echo的高電平時間，得到距離的精度是17mm
Input : none
return : 得到的距離，單位是mm
*************************************************************/
uint16_t ultrasonic_calculate(void)
{
uint16_t UltrasonicWave_Distance;
TIM_SetCounter( TIM2, 0 );
TIM_Cmd( TIM2, ENABLE );
while(GPIO_ReadInputDataBit( U_GPIO_Define.pin_of_echo_group,
U_GPIO_Define.pin_of_echo ) );
TIM_Cmd( TIM2, DISABLE );
UltrasonicWave_Distance = TIM_GetCounter(TIM2)*17;
return UltrasonicWave_Distance;
}
uint16_t ultrasonic_wave_get_result(void)
{
return ultrasonic_wave_measure_data;
}
void clear_last_measure_result(void)
{
ultrasonic_wave_measure_data = 0;
}
void ultrasonic_wave_test(void)
{
uint16_t distance_ultrasonic;
distance_ultrasonic = ultrasonic_wave_get_result();
{
printf("get ultrasonic wave distance : %d \n", distance_ultrasonic);
OLED_ShowString(10, 0, "Ultra" );
OLED_ShowString(0 , 2, "Distance:(mm)" );
OLED_ShowNum (50, 4, distance_ultrasonic , 3, 16);
clear_last_measure_result();
}
ultrasonicWave_startMeasure();
}
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