mbed rtty test

gistfile1.txt

#define RADIOPIN p23

void rtty_txstring (char * string);
void rtty_txbyte (char c);
void rtty_txbit (int bit);

DigitalOut outputPin(RADIOPIN);
char datastring[80];

int main()
{
    sprintf(datastring,"Hello World"); // Puts the text in the datastring
    rtty_txstring (datastring);
}
  


void rtty_txstring (char * string)
{

  /* Simple function to sent a char at a time to
     ** rtty_txbyte function.
   	** NB Each char is one byte (8 Bits)
   	*/

  char c;

  c = *string++;

  while ( c != '\0')
  {
    rtty_txbyte (c);
    c = *string++;
  }
}


void rtty_txbyte (char c)
{
  /* Simple function to sent each bit of a char to
   	** rtty_txbit function.
   	** NB The bits are sent Least Significant Bit first
   	**
   	** All chars should be preceded with a 0 and
   	** proceded with a 1. 0 = Start bit; 1 = Stop bit
   	**
   	*/

  int i;

  rtty_txbit (0); // Start bit

  // Send bits for for char LSB first

  for (i=0;i<7;i++) // Change this here 7 or 8 for ASCII-7 / ASCII-8
  {
    if (c & 1) rtty_txbit(1);

    else rtty_txbit(0);

    c = c >> 1;

  }

  rtty_txbit (1); // Stop bit
  rtty_txbit (1); // Stop bit
}

void rtty_txbit (int bit)
{
  if (bit)
  {
    // high
    outPin.write = 1;
  }
  else
  {
    // low
    outPin.write = 0;

  }

  //                  delayMicroseconds(3370); // 300 baud
                            // For 50 Baud uncomment this and the line below.
  wait(0.00020150); // You can't do 20150 it just doesn't work as the
                            // largest value that will produce an accurate delay is 16383
                            // See : http://arduino.cc/en/Reference/DelayMicroseconds

}