SRF08超声波传感器和dsPIC33E I2C通信问题

#include "p33EP512MU810.h"

#include "i2c.h"

#include <Initialisierung.h>

#include "Timer.h"





//Schritt 1





/*Configuring the general features of the microcontroller*/



_FGS(GSS_OFF & GWRP_OFF);

// External Oscillator

_FOSCSEL(FNOSC_PRIPLL);



_FOSC(FCKSM_CSECMD & OSCIOFNC_OFF  & POSCMD_XT);

// Clock Switching is enabled and Fail Safe Clock Monitor is disabled

// OSC2 Pin Function: OSC2 is Clock Output

// Primary Oscillator Mode: XT Crystal



_FWDT(FWDTEN_OFF);

// Watchdog Timer Enabled/disabled by user software



_FICD(ICS_PGD3 &  JTAGEN_OFF & RSTPRI_PF); 



_FPOR( BOREN_ON & ALTI2C1_OFF & ALTI2C2_OFF );

// Brown-out Reset (BOR) Detection Enable bit (BOR is enabled)

// Alternate I2C pins for I2C1 (SDA1/SCK1 pins are selected as the I/O pins for I2C1)

// Alternate I2C pins for I2C2 (SDA2/SCK2 pins are selected as the I/O pins for I2C2)





//Schritt 2



#define CFG_I2C2BRG  0x188

// (40MHz/100KHz)-2 = 0x188//I2C2=[(1/Fscl-PGD)*Fcy]-2



#define SONAR1 0xE0



unsigned int get_srf08(unsigned int SONAR);





/*** Global functions for the I2C2******************************************/

 main(void)

{

     unsigned int range1=0;

     f_Initialisierung();



    unsigned int Config1; // ConfigI2c2 represents I2C2CON register.

         Config1 = (   I2C2_ON & I2C2_IDLE_CON & I2C2_CLK_HLD &

                       I2C2_IPMI_DIS & I2C2_7BIT_ADD & I2C2_SLW_DIS &

                       I2C2_SM_DIS & I2C2_GCALL_DIS & I2C2_STR_DIS &

                       I2C2_NACK & I2C2_ACK_DIS & I2C2_RCV_DIS &

                       I2C2_STOP_DIS & I2C2_RESTART_DIS & I2C2_START_DIS

                        );



    OpenI2C2(Config1,CFG_I2C2BRG);/*The following function initializes the I2C2 bus and

                                         set the I2C2 Bus Speed to 100KHz I2C2 used to communicate with the Ultrasonic sensors*/

    IdleI2C2();



/*End Configuration I2C2*/

    while(1)

    {

        range1=get_srf08(SONAR1);

    }

 }

//Schritt 3

// Start Condition



  unsigned int get_srf08 (unsigned int SONAR)

{



    unsigned int range;  //range=Reichweiten

    unsigned char hi,lo; //high Byte,low Byte

    

 

     //StartI2C2();

        I2C2CONbits.SEN=1;         //send start bit

        while(I2C2CONbits.SEN);    //and wait fot it to clear       

     //MasterWriteI2C2(SRF08_ADDR);

        MasterWriteI2C2(0xE0);     //SRF08 I2C address

        while(I2C2STATbits.TBF);

        while(!IFS3bits.MI2C2IF);       // Wait for 9th clock cycle.

        while(I2C2STATbits.ACKSTAT);

     //MasterWriteI2C2(0x01);

        MasterWriteI2C2(0x01);    //Verstärkungsregister Adresse

        while(I2C2STATbits.TBF);

        while(!IFS3bits.MI2C2IF);       // Wait for 9th clock cycle.

        while(I2C2STATbits.ACKSTAT);       //then clear it

     //MasterWriteI2C2(0x00);

        MasterWriteI2C2(0x00);     //Verstärkung

        while(I2C2STATbits.TBF);

        while(!IFS3bits.MI2C2IF);       // Wait for 9th clock cycle.

        while(I2C2STATbits.ACKSTAT);          //then clear it

     //StopI2C2();

         I2C2CONbits.PEN=1;         //send stop bit

         while(I2C2CONbits.PEN);









     //StartI2C2();

         I2C2CONbits.SEN=1;         //send start bit

         while(I2C2CONbits.SEN);    //and wait fot it to clear

     //MasterWriteI2C2(SRF08_ADDR);

        MasterWriteI2C2(0xE0);     //SRF08 I2C address

        while(I2C2STATbits.TBF);

        while(!IFS3bits.MI2C2IF);       // Wait for 9th clock cycle.

        while(I2C2STATbits.ACKSTAT);

     //MasterWriteI2C2(0x02);

        MasterWriteI2C2(0x02);    //Reichweiten-Register Adresse

        while(I2C2STATbits.TBF);

        while(!IFS3bits.MI2C2IF);       // Wait for 9th clock cycle.

        while(I2C2STATbits.ACKSTAT);       //then clear it

     //MasterWriteI2C2(0xA0);

        MasterWriteI2C2(0xA0);     //Reichweiten=160    160*43mm+43mm = 6,9m

        while(I2C2STATbits.TBF);

        while(!IFS3bits.MI2C2IF);       // Wait for 9th clock cycle.

        while(I2C2STATbits.ACKSTAT);          //then clear it

     //StopI2C2();

         I2C2CONbits.PEN=1;         //send stop bit

         while(I2C2CONbits.PEN);









 //Schritt 4



    /*now wait for the ranging to complete. This delay is 104ms*/

     //Timer off; 16-bit mode; Prescaler 2; Input clk CPU/64



     //delay_ms(80);

        T6CON = 0x0000;

        T6CONbits.TCKPS = 2;

        // Timer6 period 419.424 ms = 2.384222171 Hz

        PR6 = 0xFFFF-0x001;         //w:?

        // 40MHz/64 = 625KHz , 625KHz/65535 = 9.537 Hz

        //                                           = 104,855 ms

        // later on 80ms required form this timer for the utrasonic

        // initializing. the calculation as it shown below:

        //

        //  PeriodofChecking80ms      65535

        // --------------------- = --------- ===> PeriodtoCheck

        //          80ms           104,855ms



        IFS2bits.T6IF = 0;                //clear old interrupt request.

        IEC2bits.T6IE = 0;                //disable interrupt.

        T6CONbits.TON = 0;                //switch timer off.





//Schritt 5



        //finally get the range form the SRF08



     //StartI2C2();

        I2C2CONbits.SEN=1;         //send start bit

        while(I2C2CONbits.SEN);    //and wait fot it to clear            

    //??????? //MasterWriteI2C2(SRF08_ADDR+1);

        MasterWriteI2C2(0xE0|0x01);     //SRF08 I2C address+Read

        while(I2C2STATbits.TBF);

        while(!IFS3bits.MI2C2IF);       // Wait for 9th clock cycle.

        while(I2C2STATbits.ACKSTAT);    //then clear it       

     //??????????????????????

        hi = MasterReadI2C2();      //read Most Significant Bit

        AckI2C2();     //start acknowledge sequence

        while(I2C2CONbits.ACKEN);//wait for ack.sequence to end;

        

        lo = MasterReadI2C2();      //read Least significant Bit       

        NotAckI2C2();     //start acknowledge sequence

        while(I2C2CONbits.ACKEN);//wait for ack.sequence to end



     //StopI2C2();

        I2C2CONbits.PEN=1;         //send stop bit

        while(I2C2CONbits.PEN);



        range = ((hi<<8)+lo);

        

  }