/* main.c
 *
 * Copyright (c) 2003-2004 Susan Cotterell.
 * Permission to copy is granted provided that this header remains
 * intact. This software is provided with no warranties.
 *
 * Version : 1.0
 *
 * Recieving PIC
 * PIC recieves various packets, and displays packet contents
 *
 */

//--------------------------------------------------------------
// libraries
//--------------------------------------------------------------

#include    <pic.h>
#include    "sci.h"
#include    "io.h"
#include    "../constants.h"

//--------------------------------------------------------------
// pin mappings
//--------------------------------------------------------------

#define EB_OUTPUT	RB0

//--------------------------------------------------------------
// global variables
//--------------------------------------------------------------

unsigned char data_val = ERROR;
unsigned rx_cnt = 0;
bit rx_error = 0;
bit rx_flag = 0;

//--------------------------------------------------------------
// function declarations
//--------------------------------------------------------------

void interrupt timer_isr(void);
void rx_isr(void);
void led_isr(void);

//--------------------------------------------------------------
// main
//--------------------------------------------------------------

main(void)
{

        // configure processor
	// -----------------------------------------------------------
        PORTA = 0xff;		// set output data latches to default value
	CMCON = 0x07;		// disable comparators to allow I/O
	TRISA = 0x00;		// all bits output
	TRISB = 0x02;		// all bits output, bit 1 input
	
	// Timer0 setup
	// -----------------------------------------------------------
	asm("CLRWDT");		// turn off watch dog timer
	OPTION = 0x47; 		// setup prescaler
	TMR0 = PRELOAD; 	// preload timer
	INTCON = 0xA0;		// setup interrupt control

	// USART setup
	// -----------------------------------------------------------
	sci_Init();			// setup USART protocol
	InitIO();			// initialzie LCD
	ClearScreen();

	// main code
	// -----------------------------------------------------------

	PrintString("hello");

	for(;;) {
	
		if( rx_flag == 1 ){

			if( rx_error == 0){ // rx trigger by input
				data_val = sci_GetByte();
			}
			else{		    // rx trigger by isr, it timed out
				data_val = ERROR;
			}

			rx_cnt = 0;
			rx_error = 0;		
			rx_flag = 0;

		if( data_val == YES ){
			ClearScreen();
			PrintString("YES");
		}
		else if( data_val == NO){
			ClearScreen();
			PrintString("NO");
		}
		else if(data_val == 0xFF){ //alive packet
			ClearScreen();
			PrintString("ALIVE");
		}
		else{
			ClearScreen();
			PrintString("ERROR");
			PutChar(data_val/100 + '0');
			PutChar(data_val%100/10 + '0');
			PutChar(data_val%10 + '0');
		}

		
		}
	}
}


//--------------------------------------------------------------
// interrupt service routine
//--------------------------------------------------------------
void interrupt timer_isr(void)
{
	T0IE = 0;	// disable timer0 interrupt
	GIE = 0;	// disables all interrupts

	if( RCIF ){     // interrupt triggered by USART
		rx_flag = 1;
	}

	rx_isr();
	
	TMR0 = PRELOAD; // preload timer
	T0IF = 0;	// clear timer overflow flag
	T0IE = 1;	// enable timer0 interrupt
	GIE = 1;	// enable all interrupts
}

//--------------------------------------------------------------
// rx process (isr called every 10 ms)
//--------------------------------------------------------------
void rx_isr(void)
{
	rx_cnt++;

	if( rx_cnt == 100 ) {
		rx_flag = 1;
		rx_error = 1;
	}
}