28335测试超声波遇到的问题，请指导

newofcortexm3

28335测试超声波遇到的问题，请指导 [复制链接]

在CCS4.1环境下编译与链接生成的文件。源码和项目文件见附件。

给超声波模块给的Trig引脚10us的高电平，用PIE中断捕获Echo引脚的高电平持续时间，最后用串口输出结果。

编译能通过，但是程序运行之后，不论距离障碍物有多远，每次超声波输出的值都相同。觉得问题有可能出在时钟。请大侠不吝赐教，谢谢！

主函数：

#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File

#include "systimer.h"

#define  LED1 GpioDataRegs.GPBDAT.bit.GPIO60

#define  LED2 GpioDataRegs.GPBDAT.bit.GPIO61

#define   Trig  GpioDataRegs.GPADAT.bit.GPIO12

#define   Echo  GpioDataRegs.GPADAT.bit.GPIO13

interrupt void xint2_isr(void);

void scic_echoback_init(void);

void scic_fifo_init(void);

void scic_xmit(int a);

void scic_msg(char *msg);

void InitLED(void);

void Init_ultrasonic(void);

Uint32 begin_time=0;

Uint32 over_time=0;

Uint32 period=0;

float displacement=0.0;

Uint32 H_displacement=0;

Uint32 L_displacement=0;

Uint16 flag=0;

void main(void)

{

   char *msg;

   

// Step 1. Initialize System Control:

// PLL, WatchDog, enable Peripheral Clocks

// This example function is found in the DSP2833x_SysCtrl.c file.

   InitSysCtrl();

// Step 2. Initalize GPIO:

// This example function is found in the DSP2833x_Gpio.c file and

// illustrates how to set the GPIO to it's default state.

// InitGpio();  // Skipped for this example

   InitScicGpio();

// Step 3. Clear all interrupts and initialize PIE vector table:

// Disable CPU interrupts

   DINT;

// Initialize the PIE control registers to their default state.

// The default state is all PIE interrupts disabled and flags

// are cleared.

// This function is found in the DSP2833x_PieCtrl.c file.

   InitPieCtrl();

// Disable CPU interrupts and clear all CPU interrupt flags:

   IER = 0x0000;

   IFR = 0x0000;

   InitPieVectTable();

   

   EALLOW; // This is needed to write to EALLOW protected registers

   PieVectTable.XINT2 = &xint2_isr;

   EDIS;   // This is needed to disable write to EALLOW protected registers

// Interrupts that are used in this example are re-mapped to

// ISR functions found within this file.

// Step 4. Initialize the Device Peripheral. This function can be

//         found in DSP2833x_CpuTimers.c

   InitCpuTimers();   // For this example, only initialize the Cpu Timers

   InitSystimer(&CpuTimer1);   //初始化CPUTimer1

// To ensure precise timing, use write-only instructions to write to the entire register. Therefore, if any

// of the configuration bits are changed in ConfigCpuTimer and InitCpuTimers (in DSP2833x_CpuTimers.h), the

// below settings must also be updated.

   StartCpuTimer1();

// Step 5. User specific code, enable interrupts:

   PieCtrlRegs.PIECTRL.bit.ENPIE = 1;          // Enable the PIE block

   PieCtrlRegs.PIEIER1.bit.INTx5 = 1;          // Enable PIE Gropu 1 INT2

   IER |= M_INT1;       

 

// Enable global Interrupts and higher priority real-time debug events:

   EINT;   // Enable Global interrupt INTM

//  ERTM;   // Enable Global realtime interrupt DBGM

   scic_fifo_init();   // Initialize the SCI FIFO

   scic_echoback_init();  // Initalize SCI for echoback

//   msg = "\r\n\n\nHello\0";

//   scic_msg(msg);

   InitLED();

   Init_ultrasonic();

   LED1=0;

   LED2=1;

   Trig=0;

   

// Step 6. IDLE loop. Just sit and loop forever (optional):

   for(;;)

   { 

     Trig=1;

     DELAY_US(10);

     Trig=0;

/*    while(1)

     {

      if(Echo==1)

      {

      //begin_time=CpuTimer1Regs.PRD.all;

      //StartCpuTimer1();    

      begin_time=CpuTimer1Regs.TIM.all;

      flag=1;

      break;

      }

      if(flag==1&&Echo==0)

      {

      //StopCpuTimer1();

      over_time=CpuTimer1Regs.TIM.all;

      period=begin_time-over_time;

      displacement=340*period*100/1000/2;

      H_displacement=(displacement>>16);

      L_displacement=displacement;

      scic_xmit(H_displacement>>8);

      scic_xmit(H_displacement); 

      scic_xmit(L_displacement>>8);

      scic_xmit(L_displacement);  

        flag=0;

      }   

      break;   

   }*/

   //period=begin_time-over_time;

   displacement=170*period*0.00667*1000;

   H_displacement=((int)displacement>>16);

   L_displacement=(int)displacement;

   scic_xmit(H_displacement>>8);

   scic_xmit(H_displacement); 

   scic_xmit(L_displacement>>8);

   scic_xmit(L_displacement);  

  }

}

void scic_echoback_init()

{

    // Note: Clocks were turned on to the SCIA peripheral

    // in the InitSysCtrl() function

  ScicRegs.SCICCR.all =0x0007;   // 1 stop bit,  No loopback

                                   // No parity,8 char bits,

                                   // async mode, idle-line protocol

ScicRegs.SCICTL1.all =0x0003;  // enable TX, RX, internal SCICLK,

                                   // Disable RX ERR, SLEEP, TXWAKE

ScicRegs.SCICTL2.all =0x0003;

ScicRegs.SCICTL2.bit.TXINTENA = 1;

ScicRegs.SCICTL2.bit.RXBKINTENA =1;

#if (CPU_FRQ_150MHZ)

     ScicRegs.SCIHBAUD    =0x0001;  // 9600 baud @LSPCLK = 37.5MHz.

     ScicRegs.SCILBAUD    =0x00E7;

#endif

#if (CPU_FRQ_100MHZ)

      ScicRegs.SCIHBAUD    =0x0001;  // 9600 baud @LSPCLK = 20MHz.

      ScicRegs.SCILBAUD    =0x0044;

#endif

ScicRegs.SCICTL1.all =0x0023;  // Relinquish SCI from Reset

}

// Transmit a character from the SCI

void scic_xmit(int a)

{

    while (ScicRegs.SCIFFTX.bit.TXFFST != 0) {}

    ScicRegs.SCITXBUF=a;

}

void scic_msg(char * msg)

{

    int i;

    i = 0;

    while(msg != '\0')

    {

        scic_xmit(msg);

        i++;

    }

}

// Initalize the SCI FIFO

void scic_fifo_init()

{

    ScicRegs.SCIFFTX.all=0xE040;

    ScicRegs.SCIFFRX.all=0x204f;

    ScicRegs.SCIFFCT.all=0x0;

}

void InitLED(void)

{

   EALLOW;

   GpioCtrlRegs.GPBMUX2.bit.GPIO60 = 0; // GPIO60 = GPIO60

   GpioCtrlRegs.GPBDIR.bit.GPIO60 = 1; 

   GpioCtrlRegs.GPBMUX2.bit.GPIO61 = 0; // GPIO61 = GPIO61

   GpioCtrlRegs.GPBDIR.bit.GPIO61 = 1;

   EDIS;

}

void Init_ultrasonic(void)

{

EALLOW; 

GpioCtrlRegs.GPAMUX1.bit.GPIO12 = 0; // GPIO12 = GPIO12

  GpioCtrlRegs.GPADIR.bit.GPIO12 = 1;  //  Output

 

  GpioCtrlRegs.GPAMUX1.bit.GPIO13 = 0; // GPIO13 = GPIO13

  GpioCtrlRegs.GPADIR.bit.GPIO13 = 0; // Input

  GpioCtrlRegs.GPAQSEL1.bit.GPIO13 = 0;        // XINT2 Synch to SYSCLKOUT only 

  EDIS;

 

  EALLOW;

    GpioIntRegs.GPIOXINT2SEL.bit.GPIOSEL = 13;   // XINT2 is GPIO13

    EDIS;

   

    EALLOW;

    XIntruptRegs.XINT2CR.bit.POLARITY = 3;      //Rising & Falling edge interrupt  

    XIntruptRegs.XINT2CR.bit.ENABLE =1;         //Enable Xint2

    EDIS;

}

interrupt void xint2_isr(void)

{

LED1=~LED1;

if(flag==0)

{

//StartCpuTimer1();

begin_time=CpuTimer1Regs.TIM.all;

      flag=1;

      LED2=~LED2;

      PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;

}

else

{

//StopCpuTimer1();

over_time=CpuTimer1Regs.TIM.all;

      period=begin_time-over_time;

      //displacement=340*period*100/1000/2;

      flag=0;

      LED2=~LED2;

      PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;

}

}

hlx3012

这个问题是程序问题还是超声模块的问题，我建议你确认一下。

如果是程序问题你可以通过示波器监测芯片和超声模块之间的通信时序检查问题。

安_然

#define  LED1GpioDataRegs.GPBDAT.bit.GPIO60
#define  LED2GpioDataRegs.GPBDAT.bit.GPIO61


这是笔误还是程序中就是这样写的。

dontium

 

[ 本帖最后由 dontium 于 2012-4-28 18:30 编辑 ]

newofcortexm3

这个是笔误。

newofcortexm3

超声波是没问题的，用Atemga 8 能正常驱动。

381287267

楼主可以看看你的代码吗