/*
////////////////
	CharliePlexed Emergency lights
	v1 : Very basic implementation
	Matt Casey : 23 Feb 2008
	matt@catmacey.com
	
	8 Charlieplexed LEDs on Portb[4-7]
	Red in one direction : Blue in the other.
	Could use 12 LEDs if I made a bigger PCB
////////////////
*/

/*
////////////////
Todo:

	*	Use PWM to control output intensity of individual LEDs.
	*	Create patterns to simulate rotation of lightsources by varying intensity of neighbouring LEDS
	*	Simulate inertia of mechanical rotating systems
	*	Simulate power up/power down of real bulbs using pwm
	*	Use Interrupt to drive display : ISR is defined but not used right now

////////////////
*/

#include <p18cxxx.h>
#include <delays.h>
#include <usart.h>
#include <stdio.h>
#include <timers.h>
#include <adc.h>
#include <portb.h>

//PortA
//outputs
#define	led0					PORTAbits.RA0	//LED ind to show system is running
#define 	btn0					PORTAbits.RA5

//Port B
//inputs
//outputs
#define	cp0					PORTBbits.RB4	//Charliplex 0
#define	cp1					PORTBbits.RB5	//Charliplex 1
#define	cp2					PORTBbits.RB6	//Charliplex 2
#define	cp3					PORTBbits.RB7	//Charliplex 3

//Port C
#define	TX		PORTCbits.RC6
#define	RX		PORTCbits.RC7

#define TRISB_DEF 0b11110000

//setup defs for charlieplexing b7-4 are port state : b3-0 are tris
rom	char charlieBits[] = {
		0b10000011
	,	0b01001001
	,	0b00101100
	,	0b00010110
	
	,	0b01000011
	,	0b00101001
	,	0b00011100
	,	0b10000110
	};


//func prototypes
void boot_up(	void );
void timer_isr (void);
void ledOn (unsigned char ledNum);
void ledOff ();


#pragma	code low_vector=0x18
void
low_interrupt	(void){
	_asm GOTO	timer_isr	_endasm
}
#pragma	code

#pragma	interruptlow timer_isr
void timer_isr (void){
	//int
	signed char rtn;
	unsigned char tmp;
	
	if(INTCONbits.TMR0IF){
		//Timer 0 int
		
		INTCONbits.TMR0IF	=	0;	//reset	timer 0
	}
}//func

void main(){
	unsigned char	ctr			= 0;	//gp counter
	unsigned char tmp;	
	unsigned char btn			= 0;	
boot_up();	//inti the peripherals
	Delay1KTCYx(10);
	
	INTCONbits.GIE 					= 0;	//halt ints

	PORTB	=	0b10101010;

	while(1){
		btn = 0;
		//Turn on LED
		ledOn(ctr);
		fprintf(_H_USART, "\r\n%.1u : %.8b : %.8b ",ctr, PORTB, TRISB);
		while(btn < 20){
			//wait here for a button press of at least 20K ticks 
			Delay1KTCYx(1);
			if(btn0 == 0) btn++;
			else btn = 0;
		}
		
		ctr++;
		if(ctr > 7) ctr = 0;
		led0 = ~led0;
		Delay10KTCYx(30);
	}//end while
}

/*
	Sets all LEDs off by setting chalie pins to high impedance
*/
void ledOff (){
	//reset all charlie pins to high impedance (input)
	TRISB = TRISB_DEF;
}


/*
	Sets a given led on using charlieplexing
*/
void ledOn (unsigned char ledNum){
	//reset all charlie pins to high impedance (input)
	unsigned char tmp;
	TRISB = TRISB_DEF;
	//set output status : use masking to retain b3-0
	tmp = (PORTB & 0b00001111) | (charlieBits[ledNum] & 0b11110000);
	PORTB = tmp;
	//set tris : Use mask to retain b3-0
	tmp = (TRISB & 0b00001111) | ((charlieBits[ledNum] << 4) & 0b11110000);
	TRISB = tmp;
}


void boot_up(void){
	//Setup Ports
	CMCON			= 0b00000111;	//Turn off comparator on RA port ]
	LATA				= 0b00000000;
	PORTB				= 0b00000000;
	LATC				= 0b00000000;
	TRISA				= 0b00100000;	// 0= out, 1 = in
	TRISB				= 0b11111111;	// 0= out, 1 = in
	TRISC				= 0b00011000;	// 0= out, 1 = in
	ADCON1			= 0b00001111;	// set portA bits0-3 to digital IO
	//Open the USART configured as 8N1, 115200 baud, in polled mode
	OpenUSART	(USART_TX_INT_OFF	&
						 USART_RX_INT_ON &
						 USART_ASYNCH_MODE &
						 USART_EIGHT_BIT &
						 USART_CONT_RX &
						 USART_BRGH_HIGH, 10);

	//setup Timer0 : Use for GPIO output
	OpenTimer0(TIMER_INT_ON & T0_8BIT & T0_SOURCE_INT & T0_PS_1_4);
	
	//Disable ints for the mo
	INTCONbits.GIE = 0;	//Stop	ints
	Delay10KTCYx(10);//wait for stable
	putrsUSART ((const far rom char	*)"\r\n\r\n\r\n\r\n////////////////\r\nBootup completed\r\n");
}