I2C driver for SRF02

srf02.c

/*
 * srf02.c
 *
 *  Created on: 26 Jan 2013
 *      Author: David
 */
//includes

#include "lm4f120h5qr.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/i2c.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "I2C_Stellaris_API.h"
#include "utils/uartstdio.h"
#include "driverlib/sysctl.h"


// variables


int srf02datalow=0;
int srf02datahigh=0;
int readings[10]={0,0,0,0,0,0,0,0,0,0};      // the readings from SRF02 pings
int index = 0;                   			 // the index of the current reading
int total = 0;                  			 // the running total
int average = 0;
int i=0;

// functions

int read_srf02(void){

        for(i = 0; i < 10; i++){
       total= total - readings[index];
        // read from the sensor:
       I2CRegWrite(I2C3_MASTER_BASE, 0xF0,0x00,0x51);
        SysCtlDelay(800000);
       readings[index] = I2CRegRead(I2C3_MASTER_BASE,0xF0,0x03);
        // add the reading to the total:
       total= total + readings[index];
        // advance to the next position in the array:
       index = index + 1;

        // if we're at the end of the array...
        if (index >= 10)
               // ...wrap around to the beginning:
              index = 0;

        // calculate the average:
       average = total / 10;
       }
        return average;

};