Programming XBee to transmit and receive data

Projects Programming
34

I changed the switch statement into an "if" and the if(XBeeRX.available()) to while(XBeeRX.available())

For some reason nothing shows up in the COM port which is connected to the receiver. I introduced a delay between the transmissions in the transmitter side. These are my codes :

TRANSMITTER

#include <SoftwareSerial.h>
#include <i2cmaster.h>

SoftwareSerial XBeeTX(2, 3); // RX, TX

byte dev = 0x5A<<1;
char data_start = '*';

void setup()
{
  Serial.begin(9600);
  XBeeTX.begin(9600);
  i2c_init(); //Initialise the i2c bus
  PORTC = (1 << PORTC4) | (1 << PORTC5);//enable pullups
}

void loop()
{
  byte data_low;
  byte data_high;
  byte pec = 0;

  i2c_start_wait(dev+I2C_WRITE);
  i2c_write(0x07);

  // read
  i2c_rep_start(dev+I2C_READ);
  data_low = i2c_readAck(); //Read 1 byte and then send ack
  data_high = i2c_readAck(); //Read 1 byte and then send ack
  pec = i2c_readNak();
  i2c_stop();

  Serial.println(data_start, HEX);
  XBeeTX.print(data_start, HEX);
  delay(40);
  Serial.println(data_high, HEX);
  XBeeTX.print(data_high, HEX);
  delay(40);
  Serial.println(data_low, HEX);
  XBeeTX.print(data_low, HEX);
  delay(40);
  delay(1000);
}

RECEIVER

#include <SoftwareSerial.h>
#include <ctype.h>

SoftwareSerial XBeeRX(2, 3); // RX, TX

char data_start = 0x2A;
boolean newReading;
byte readPosition;
byte data_low;
byte data_high; 
char data_in;

void setup()
{
  Serial.begin(9600);
  XBeeRX.begin(9600);
}

void loop()
{
  while (XBeeRX.available())
  {
    data_in = XBeeRX.read();

    if(readPosition==0 && data_in==data_start)
    {  
      readPosition++;
    }

    if(readPosition==1)
    {
      data_high = HexCharToValue(data_in)<<4;
      readPosition++;
    }

    if(readPosition==2)
    {
      data_high = HexCharToValue(data_in)+data_high;
      readPosition++;
    }

    if(readPosition==3)
    {
      data_low = HexCharToValue(data_in)<<4;
      readPosition++;
    }

    if(readPosition==4)
    {
      data_low = HexCharToValue(data_in)+data_low;
      readPosition = 0;
      newReading = true;
    }
  }

  if (newReading == true)
  {
    Serial.println(data_start, HEX);
    Serial.println(data_high, HEX);
    Serial.println(data_low, HEX);  

    double tempFactor = 0.02;
    double tempData = 0x0000;
    int frac;

    tempData = (float)(((data_high & 0x007F) << 8) + data_low);
    tempData = (tempData * tempFactor)-0.01;

    float celcius = tempData - 273.15;

    Serial.print("Celcius: ");
    Serial.println(celcius);
    newReading = false;
  }
}

byte HexCharToValue (char x)
{
  byte value;
  int upper;
  byte first_result;

  if(isxdigit(x))
  {
    upper = toupper(x);
    first_result = upper - 0x30;
    if (first_result < 0x0A)
    {
      value = first_result;
    }
    else
    {
      value = first_result - 0x10;
      value = value + 10;
    }
  }
  else
  {
    value = 0;
  }

  return value;
}

Could anyone have any idea why nothing seems to show up in the receiver COM port?