//
// More Loops.c
// Exercise 3-2 
// two switches detect sweep direction and reverse the sequence
//

#include <p24fj128ga010.h>

// 1. define timing constant
#define SHORT_DELAY 100
#define LONG_DELAY	800

// 2. declare and initialize an array with the message bitmap 
char bitmap[30] = { 
	0b11111111,	// H
	0b00001000,
	0b00001000,
	0b11111111,
	0b00000000,
	0b00000000,
	0b11111111,	// E
	0b10001001,
	0b10001001,
	0b10000001,
	0b00000000,
	0b00000000,
	0b11111111,	// L
	0b10000000,
	0b10000000,
	0b10000000,
	0b00000000,
	0b00000000,
	0b11111111,	// L
	0b10000000,
	0b10000000,
	0b10000000,
	0b00000000,
	0b00000000,
	0b01111110,	// O
	0b10000001,
	0b10000001,
	0b01111110,
	0b00000000,
	0b00000000
	};
	
// 3. the main program
main()
{
	// 3.1 variable declarations
	int i;              // i will serve as the index 
	
	// 3.2 initialization
	TRISA =  0;         // all PORTA as output
	T1CON =  0x8030;    // TMR1 on, prescale 1:256 Tclk/2
	
	// 3.3 the main loop   	
	while( 1)
	{
    	// 3.3.0 wait for S3 to be pressed
    	while( _RD6 && _RD13);
    	
    	if (!_RD6)  // direct sweep
    		// 3.3.1 display loop, hand moving to the right
    		for( i=0; i<30; i++)
    		{	// 3.3.1.1 update the LEDs
    			PORTA = bitmap[i];
    				
    			// 3.3.1.2 short pause
    			TMR1 = 0;
    			while ( TMR1 < SHORT_DELAY)
    			{
    			}
    		} // for i

        else
    		// 3.3.2 inverted display sequence 
    		for( i=30; i>0; i--)
    		{	// 3.3.1.1 update the LEDs
    			PORTA = bitmap[i];
    				
    			// 3.3.1.2 short pause
    			TMR1 = 0;
    			while ( TMR1 < SHORT_DELAY)
    			{
    			}
    		} // for i
			
	} // main loop
} // main