void setup()
{

  /* Speed up timer 2 to make pins 3 and 11 output a blistering fast PWM. */
  TCCR2B = TCCR2B & 0b11111000 | 1;
  TCCR2A &= ~B11;
  TCCR2A |=  B011;
  pinMode( 3, OUTPUT );
  pinMode( 11, OUTPUT );

  /* Do the same for timer 0.  WARNING: Much of the Arduino library relies on timer 0 and you will find some functions output incorrect values.  Look up the full effects and make sure you don't need it. */
  TCCR0B = TCCR0B & 0b11111000 | 1;
  TCCR0A &= ~B11;
  TCCR0A |=  B011;
  pinMode( 5, OUTPUT );
  pinMode( 6, OUTPUT );

  analogWrite( 3, 0 );
  analogWrite( 11, 0 );
  analogWrite( 5, 0 );
  analogWrite( 6, 0 );

  /* Set the reference level to 1.1v */
  analogReference( INTERNAL );

  /* Increase our input speed - prescaler to /8 */
  _SFR_BYTE( ADCSRA ) &= ~_BV( ADPS2 );
  _SFR_BYTE( ADCSRA ) |= _BV( ADPS1 );
  _SFR_BYTE( ADCSRA ) |= _BV( ADPS0 );

  /* Our LED. */
  pinMode( 13, OUTPUT );

}

void loop()
{

    /* Take our left and right inputs and convert them from 10-bit unsigned (0 ... 1023) to 16-bit signed (-32768 ... 32767). */
    int Left = ( analogRead( 0 ) * 64 ) - 32768;
    int Right = ( analogRead( 1 ) * 64 ) - 32768;

    /* Process them here. */

    /* Shift the signed variables into unsigned 16-bit for output (0 ... 65535). */
    unsigned short LeftOut = Left + 32768;
    unsigned short RightOut = Right + 32768;

    /* Write our outputs.  We want the two halves of the unsigned 16-bit as unsigned 8-bits, so we shift it to the right, chopping off the 8 least significant bits, and also take just the 8 least for the other pin. */
    analogWrite( 3, LeftOut >> 8 );
    analogWrite( 11, LeftOut & 255 );
    analogWrite( 5, RightOut >> 8 );
    analogWrite( 6, RightOut & 255 );

}