/* Example Sketch for a TellyMate Shield */
/* Random Characters */

/* Simple helper functions */
#define CHAR_ESC "\x1B"
void cursor_move( uint8_t row , uint8_t col )
{ // <ESC>Yrc
  Serial.print( CHAR_ESC "Y" ) ;
  Serial.print((unsigned char)(32 + row)) ;
  Serial.print((unsigned char)(32 + col)) ;
}

void cursor_show( bool show )
{ // <ESC>e or <ESC>f
   Serial.print( CHAR_ESC ) ;
   Serial.print( show?'e':'f' ) ;
}

void screen_clear( void )
{ // <ESC>E
  Serial.print( CHAR_ESC "E" );
}

/* The actual sketch */
void setup()
{
  Serial.begin( 57600 ) ; // set to 57600 baud
  screen_clear() ;
  cursor_show( false ) ; // turn the cursor off
}

void loop()
{
  //move the cursor to a random place on the screen.
  cursor_move( random( 25 ) , random( 38 ) ) ;

  // print a random character.  Characters below 31 need special handling, so (for simplicity) use values between 32 and 255
  Serial.print( (unsigned char) random( 32, 256 ) ) ;
     // the (unsigned char) cast ensures that the int returned by random() is treated as a char when passed to Serial.print().
     // without the cast, the Serial.print function will display the int value as a number on the screen rather than the character with that value.
}