Reading Serial Data from MaxSonar (MB7369) to an Arduino

Hi all! I’m kinda new to Arduino and a total noob on serial data. I bought a MaxSonar(MB7369) and im trying to use its Pin 5 (RS232 output) to measure the distance. I used a RS232 to TTL converter (Max232) to be able to read the data. When I connect it to an Arduino and upload a blank code, the serial monitor shows the R-Distance Values continuously. However, if I input a code, the serial monitor outputs no data (at random instances it does but just once) :

/* test function to Parse data from MaxSonar serial data
 and return integer */

#include <SoftwareSerial.h>

#define txPin 0                                            //define pins used for software serial for sonar
#define rxPin 1

SoftwareSerial sonarSerial(rxPin, txPin, false);            //define serial port for recieving data, output from maxSonar is inverted requiring true to be set.


boolean stringComplete = false;

void setup()
{
  Serial.begin(9600);                                      //start serial port for display
  sonarSerial.begin(9600);                                 //start serial port for maxSonar
  //delay(500);                                              //wait for everything to initialize

}

void loop()
{
  int range = EZread();
  if(stringComplete)
  {
    stringComplete = false;                                //reset sringComplete ready for next reading


    //delay(500);                                          //delay for debugging
  }
}


int EZread() 
{
  int result;
  char inData[6];                                          //char array to read data into
  int index = 0;


  sonarSerial.flush();                                     // Clear cache ready for next reading

  while (stringComplete == false) {
    //Serial.print("reading ");    //debug line
      if (sonarSerial.available())
    {
      char rByte = sonarSerial.read();                     //read serial input for "R" to mark start of data
      if(rByte == 'R')
      {
        Serial.println("rByte set");
        while (index < 5)                                  //read next 4 characters for range from sensor
        {
          if (sonarSerial.available())
          {
            inData[index] = sonarSerial.read(); 
            Serial.println(inData[index]);               //Debug line

            index++;                                       // Increment where to write next
          }
        }
        inData[index] = 0x00;                              //add a padding byte at end for atoi() function
      }

      rByte = 0;                                           //reset the rByte ready for next reading

      index = 0;                                           // Reset index ready for next reading
      stringComplete = true;                               // Set completion of read to true
      result = atoi(inData);                               // Changes string data into an integer for use
    }
  }

  return result;
}

(code from Piano_Man)How is this possible? If anyone could help me with the code to read the data It would be very helpful!

Thanks in advance!

Hi all! It seems that no value is stored in the serial buffer from the sensor. And the data that overrides the program is from using pins 0 and 1 (which also acts as USB) so I used pins 18 and 19 instead. When i try the sonar.Available, no data seems to be stored that's why there is no output in the serial monitor. How do I make sure that the serial output from the sensor is stored in the serial buffer?