#define PICK          0   // The pin on which the pick is connected
#define SWITCH        9   // The pin on which the serial/switch switch 
                          // is connected

#define SERIAL_MODE   0   // Indicate The MIDI Pick is in serial mode
#define SWITCH_MODE   1   // Indicate The MIDI Pick is in switch mode
#define THRESHOLD     100 // The threshold that must be passed to
                          // switch from sending a 1 to sending a 0,
                          // and vice versa, when the physical switch
                          // is in "switch" mode.

void run( void )
{
loop_start:
   static int scaled_pick_value = 0;   // The MIDI Pick's pressure val
   static int physical_switch   = 0;   // State of the onboard switch
   static int all_leds          = 127; // full pressure (CHANGE)
   static int half_leds         = 64;  // half pressure (CHANGE)
   static int previous_value    = 0;   
   static int send              = 0;

   physical_switch = digitalRead( SWITCH );

   ( physical_switch == SERIAL_MODE ) ? 
      turn_on_serial_led() : turn_on_switch_led();

   // 1. Read the pin on which The MIDI Pick's force-sensing resistor
   //    transmits data.
   // 2. Divide that number by 8, which scales the highest value
   //    down to 128.
   // 3. Assign that value to the int variable scaled_pick_value, then
   //    check it against the previous_value.
   //
   // If the current value of the pick is the same as the previous, 
   // branch to the beginning of this loop for a new datum.
   if((scaled_pick_value = (analogRead( PICK ) / 8)) == previous_value)
      goto loop_start;

   // If the physical switch is in serial mode, turn on the pressure
   // leds.  (How many of those leds will light up depends on how
   // hard the pick is being pressed.)  Then, send data long the 
   // bluetooth connection.
   if( physical_switch == SERIAL_MODE )
   {
      gauge_pressure( &scaled_pick_value );
      send_data( &scaled_pick_value );
   }
   else
   // The physical switch is in switch (not serial) mode, which means 
   // that I must test for finger pressure exceeding a certain 
   // THRESHOLD.  If the scaled_pick_value execeeds the THRESHOLD,
   // then I need to switch from sending a 1 to sending a 0, or 
   // vice versa.
   {
      if( scaled_pick_value > THRESHOLD )
         // I'm sending either a 0 or a 1.  If I'm currently sending
         // a 0, then assign 1 to variable send, turn on 3 of the 
         // 5 LEDs, send a 1 along the bluetooth connection, wait
         // for 250 milliseconds (1/4 of a second), and proceed.
         if( send == 0 )
         {
            send = 1;
            gauge_pressure( &all_leds );
            send_one();
            delay( 250 );
         }
         else
         {
            send = 0;
            gauge_pressure( &half_leds );
            send_zero();
            delay( 250 );
         }
   }
}