ultrasonic_App.c
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上传日期:2022-08-06
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文件大小:10k
源码类别:
嵌入式/单片机编程
开发平台:
Asm
- //========================================================================
- // 文件名称: ultrasonic_App.c
- // 功能描述: 超声波测距模组V2.0的功能接口函数
- // 维护记录: 2006-02-21 V2.0
- //========================================================================
- #include "SPCE061A.h"
- #define LONG_SEND_TIMER 1000 //中距测距时的40KHz信号发射时长
- #define LONG_SEND_TIMER2 3000 //中距测距的补充测距时的40KHz信号发射时长
- #define LONG_WAIT_DELAY 600 //中距测距的防余波干扰延时时长
- #define LONG_WAIT_DELAY2 1500 //中距测距的补充测距时的防余波干扰延时时长
- #define LONG_RES_ADD 0x00B0 //中距测距的结果补偿值
- #define LONG_RES_ADD2 0x0220 //中距测距的补充测距时的结果补偿值
- #define LOW_SEND_TIMER 250 //短距测距时的40KHz信号发射时长
- #define LOW_SEND_TIMER2 1000 //短距测距的补充测距时的40KHz信号发射时长
- #define LOW_WAIT_DELAY 180 //短距测距的防余波干扰延时时长
- #define LOW_WAIT_DELAY2 400 //短距测距的补充测距时的防余波干扰延时时长
- #define LOW_RES_ADD 0x0034 //短距测距的结果补偿值
- #define LOW_RES_ADD2 0x00B0 //短距测距的补充测距时的结果补偿值
- unsigned int Counter_buf; //超声波测距当中,用于保存TimerB计数的变量,相当于时长
- unsigned int EXT1_IRQ_flag=0; //外部中断标志变量,用于EXT1的IRQ中断程序和测距程序同步
- //========================================================================
- // 语法格式: void Initial_ult(void)
- // 实现功能: 超声波测距模组的初始化子程序
- // 参数: 无
- // 返回值: 无
- //========================================================================
- void Initial_ult(void)
- {
- unsigned int uiTemp;
- // 初始化端口主要是IOB8和IOB9
- uiTemp = *P_IOB_Dir;
- uiTemp = uiTemp|0x0200;
- uiTemp = uiTemp&0xfeff;
- *P_IOB_Dir = uiTemp;
- uiTemp = *P_IOB_Attrib;
- uiTemp = uiTemp|0x0200;
- uiTemp = uiTemp&0xfeff;
- *P_IOB_Attrib = uiTemp;
- uiTemp = *P_IOB_Buffer;
- uiTemp = uiTemp|0x0300;
- *P_IOB_Data = uiTemp;
- }
- //========================================================================
- // 语法格式: void Delay_ult(unsigned int timers)
- // 实现功能: 超声波测距模组的延时子程序
- // 参数: unsigned int timers 延时的时长(仅是一个相对量)
- // 返回值: 无
- //========================================================================
- void Delay_ult(unsigned int timers)
- {
- unsigned int i;
- for(i=0;i<timers;i++)
- {
- __asm("nop");
- }
- }
- //========================================================================
- // 语法格式: unsigned int Resoult_ult(unsigned int Counter)
- // 实现功能: 超声波测距模组的测距数据处理程序,将TimerB的计数值换算为距离
- // 参数: Counter 需要换算的计数值
- // 返回值: 计算后的距离,厘米为单位
- //========================================================================
- unsigned int Resoult_ult(unsigned int Counter)
- {
- unsigned int uiTemp;
- unsigned long ulTemp;
- ulTemp = (unsigned long)Counter*33500;
- ulTemp = ulTemp/196608;
- ulTemp = ulTemp>>1; //除二
- uiTemp = (unsigned int)ulTemp;
- return uiTemp;
- }
- //========================================================================
- // 语法格式: unsigned int measure_ult(unsigned int type)
- // 实现功能: 超声波测距模组的测距程序,完成一次测距
- // 参数: type 选择测距类型,
- // type=1 中距测距
- // type=0 短距测距
- // 返回值: 所测得的距离,以厘米为单位
- //========================================================================
- unsigned int measure2_ult(unsigned int type);
- unsigned int measure_ult(unsigned int type)
- {
- unsigned int Exit_flag = 1;
- unsigned int uiTemp;
- unsigned int uiResoult;
- unsigned int uiSend_Timer,uiWait_Timer,uiRes_Add;
- unsigned int uiSystem_Clock;
- uiSystem_Clock = *P_SystemClock; //将当前的系统时钟设置暂时保存起来
- *P_SystemClock = 0x0088; //将系统时钟设置为49MHz,分频比为1,强振模式
- if(type) //根据type即测距类型,选择不同的测距参数
- {
- uiSend_Timer = LONG_SEND_TIMER;
- uiWait_Timer = LONG_WAIT_DELAY;
- uiRes_Add = LONG_RES_ADD;
- }
- else
- {
- uiSend_Timer = LOW_SEND_TIMER;
- uiWait_Timer = LOW_WAIT_DELAY;
- uiRes_Add = LOW_RES_ADD;
- }
- *P_TimerB_Data = 0xfed2;
- *P_TimerB_Ctrl = 0x03c0; //enable 40KHz out
- Delay_ult(uiSend_Timer); //delay for send the signal
- *P_TimerB_Ctrl = 0x0006; //stop 40KHz out
- *P_TimerB_Data = 0x0000;
- *P_TimerB_Ctrl = 0x0001; //TimerB work as a counter at 192KHz
- while(*P_TimerB_Data<uiWait_Timer) //等待一定时间后再打开TimerA的计数(来源于EXT1)
- { //以避开余波的干扰
- *P_Watchdog_Clear = 0x0001;
- }
- *P_INT_Clear = 0x0100; //开中断前先清中断
- *P_INT_Ctrl = *P_INT_Ctrl_New|0x0100;
- *P_INT_Clear = 0xffff; //清除中断发生标志
- __asm("IRQ ON"); //打开总中断使能
- EXT1_IRQ_flag = 0; //TimerA的溢出中断的标志变量置0
- while(Exit_flag)
- {
- if(EXT1_IRQ_flag==1) //当该变量在timerA的FIQ中断中被置1时表示接收到了回波
- {
- Exit_flag = 0; //exit
- Counter_buf = Counter_buf+uiRes_Add;//计数值加上一定的调整数据
- uiResoult = Resoult_ult(Counter_buf);//对计数值进行处理,得出距离值
- }
- if(*P_TimerB_Data>10000) //如计数值大于10000,表示超时
- {
- Exit_flag = 0; //exit
- uiResoult = measure2_ult(type);//再进行一次补充的测距,将会加长40KHz信号发射的量
- *P_TimerB_Ctrl = 0x0006; //stop timerB
- }
- uiTemp = *P_TimerB_Data;
- *P_Watchdog_Clear = 0x0001;
- }
- *P_INT_Ctrl = *P_INT_Ctrl_New&(~0x0100); //关掉外部中断
- __asm("IRQ OFF"); //关掉总中断
- *P_SystemClock = uiSystem_Clock; //恢复系统时钟的设置
- return uiResoult;
- }
- //========================================================================
- // 语法格式: void EXT1_IRQ_ult(void)
- // 实现功能: 超声波测距模组的测距程序的EXT1中断服务程序,在EXT1的IRQ中断
- // 中调用
- // 参数: 无
- // 返回值: 无
- //========================================================================
- void EXT1_IRQ_ult(void)
- {
- Counter_buf = *P_TimerB_Data; //save the timerB counter
- *P_TimerB_Ctrl = 0x0006; //stop timerB
- *P_INT_Ctrl = *P_INT_Ctrl_New&(~0x0100); //关掉外部中断
- *P_INT_Clear = 0xffff; //清除中断发生标志
- EXT1_IRQ_flag = 1; //通知测距程序,外部中断已发生
- }
- //========================================================================
- // 语法格式: unsigned int measure2_ult(void)
- // 实现功能: 补充进行一次远距的测量,以保证能够获取测量结果
- // 参数: type 选择测距类型,
- // type=1 中距测距
- // type=0 短距测距
- // 返回值: 所测得的距离,以厘米为单位
- //========================================================================
- unsigned int measure2_ult(unsigned int type)
- {
- unsigned int Exit_flag = 1;
- unsigned int uiResoult;
- unsigned int uiSend_Timer,uiWait_Timer,uiRes_Add;
- *P_TimerA_Ctrl = 0x0006; //stop TimerA
- *P_INT_Ctrl = *P_INT_Ctrl_New&(~0x0100); //关掉外部中断
- __asm("IRQ OFF"); //关掉总中断
- *P_INT_Clear = 0xffff; //清除掉中断发生标志
- if(type) //根据type即测距类型,选择不同的测距参数
- {
- uiSend_Timer = LONG_SEND_TIMER2;
- uiWait_Timer = LONG_WAIT_DELAY2;
- uiRes_Add = LONG_RES_ADD2;
- }
- else
- {
- uiSend_Timer = LOW_SEND_TIMER2;
- uiWait_Timer = LOW_WAIT_DELAY2;
- uiRes_Add = LOW_RES_ADD2;
- }
- *P_TimerB_Data = 0xfed2;
- *P_TimerB_Ctrl = 0x03c0; //enable 40KHz out
- Delay_ult(uiSend_Timer); //delay for send the signal
- *P_TimerB_Ctrl = 0x0006; //stop 40KHz out
- *P_TimerB_Data = 0x0000;
- *P_TimerB_Ctrl = 0x0001; //TimerB work as a counter at 192KHz
- while(*P_TimerB_Data<uiWait_Timer) //等待一定时间,以避开余波的干扰
- {
- *P_Watchdog_Clear = 0x0001;
- }
- *P_INT_Ctrl = *P_INT_Ctrl_New|0x0100;//打开外部中断
- *P_INT_Clear = 0xffff; //清除中断发生标志
- __asm("IRQ ON"); //打开总中断使能
- EXT1_IRQ_flag = 0; //TimerA的溢出中断的标志变量置0
- while(Exit_flag)
- {
- if(EXT1_IRQ_flag==1) //当该变量在timerA的FIQ中断中被置1时表示接收到了回波
- {
- Exit_flag = 0; //exit
- Counter_buf = Counter_buf+uiRes_Add;//计数值加上一定的调整数据
- uiResoult = Resoult_ult(Counter_buf);//对计数值进行处理,得出距离值
- }
- if(*P_TimerB_Data>10000) //如计数值大于10000,表示超时
- {
- Exit_flag = 0; //exit
- uiResoult = 0; //error return data 0
- *P_TimerB_Ctrl = 0x0006; //stop timerB
- }
- }
- return uiResoult;
- }
- //========================================================================
- // 语法格式: unsigned int measure_Times(unsigned int type)
- // 实现功能: 组合进行共6次的测距程序,包括对6次测量结果的取平均值处理
- // 参数: type 选择测距类型,
- // type=1 中距测距
- // type=0 短距测距
- // 返回值: 所测得的距离,以厘米为单位
- //========================================================================
- unsigned int measure_Times(unsigned int type)
- {
- unsigned int uiResoult=0,uiMeasure_Index=0,i;
- unsigned int uiTemp_buf[6],uiTemp;
- unsigned int uiSystem_Clock;
- for(;uiMeasure_Index<6;uiMeasure_Index++)
- { //循环进行四次测量
- uiTemp = measure_ult(type); //进行一次测量,测量类型由type决定
- if(uiMeasure_Index==0) //如果为本次测量的第一次测距,则直接保存在缓冲区第一个单元
- uiTemp_buf[0] = uiTemp;
- else
- { //否,则对结果进行比较,进行排序,从大到小排
- i = uiMeasure_Index;
- while(i) //以下为排序的代码
- {
- if(uiTemp>uiTemp_buf[i-1])
- {
- uiTemp_buf[i] = uiTemp_buf[i-1];
- uiTemp_buf[i-1] = uiTemp;
- }
- else
- {
- uiTemp_buf[i] = uiTemp;
- break; //退出排序
- }
- i--;
- }
- }
- //两次测量之间的延时等待,利用以下代码软仿真时的cycles数结合设置的CPUCLK进行计算,大概72ms
- uiSystem_Clock = *P_SystemClock; //将之前的系统时钟的设置用变量保存
- *P_SystemClock = 0x000b; //设置为FSYS=24.576MHz 分频比为8
- for(i=0;i<5;i++)
- {
- Delay_ult(1000); //调用延时程序
- *P_Watchdog_Clear = 0x0001;
- }
- *P_SystemClock = uiSystem_Clock; //恢复系统时钟设置
- //此处延时结束
- }
- //对6次测距的结果进行处理
- if(uiTemp_buf[5]==0)
- { //如果缓冲区中的最小的测距值为0,则采用中间4个数据进行平均
- uiResoult = uiTemp_buf[1]+uiTemp_buf[2]+uiTemp_buf[3]+uiTemp_buf[4];
- uiResoult = uiResoult/4;
- }
- else
- { //否则就取后5个数据进行平均
- uiResoult = uiTemp_buf[1]+uiTemp_buf[2]+uiTemp_buf[3]+uiTemp_buf[4]+uiTemp_buf[5];
- uiResoult = uiResoult/5;
- }
- return uiResoult;
- }