#include <pic18.h>

#include "barcode.h"


/*************************
 globals
 ************************/
char global_barcode_buffer[14];


/***********************
 module vars 
 *************************/

unsigned char barcode_length;
bit barcode_ready;

/*************************
 function
 *************************/

void barcode_init(void)
{
	SPEN = 0; //Make sure serial port is disabled
	
	// snupset fra  Kim H Pedersens serialmain.c 
	// Set Port C bit 6 output (TxD) and bit 7 input (RxD)
    TRISC6 = 0;
    TRISC7 = 1;
/*
    SPBRG = 25;		//	x = Fosc/(16 * Baud Rate) - 1
					//	x = 4000000/(16 * 9600) - 1
					//	x = 25.0417 ~ 25
					//	Baud Rate = Fosc/(16 * (x+1))
					//	Baud Rate = 4000000/(16 * (25+1))
					//	Baud Rate = 9615
					*/
					
	SPBRG = 130; //BRG værdi for 20Mhz MCU
    TXSTA = 0x24;	//	TXSTA7 = 0	Don't care in asynchronous
					//	TXSTA6 = 0	8-bit transmission
					//	TXSTA5 = 1	Transmit enabled
					//	TXSTA4 = 0	Asynchronous mode
					//	TXSTA3 = 0	Unimplemented
					//	TXSTA2 = 1	High speed
					//	TXSTA1 = 0	TSR empty
					//	TXSTA0 = 0	9th bit						
    RCSTA = 0x90;	//	RCSTA7 = 0	Serial port disabled
					//	RCSTA6 = 0	8-bit reception
					//	RCSTA5 = 0	Don't care in asynchronous
					//	RCSTA4 = 1	Receiver enabled
					//	RCSTA3 = 0	Don't care (8-bit operation)
					//	RCSTA2 = 0	No framing error
					//	RCSTA1 = 0	Overrun error bit
					//	RCSTA0 = 0	9th bit						

	//config completed
	SPEN = 1; //Enable Serial port
	
	//Set module-scope variables
	barcode_length = 0;
	barcode_ready = 0;
	
	//Configure interrupts
	TXIE = 0; //Disable AUX TX interrupt - testes med TXIF;
	RCIE = 1; //Enable AUX Recieve interrupt - testes med RCIF;

	IPEN = 0; // IPEN=Interrupt Priority ENable bit - her bruges ingen prioritet
	
	PEIE = 1; // PEIE = PEriphal Interrupt Enable
		
	TXIF = 0; //nulstil intterupt flag
	RCIF = 0;

	GIE = 1; //Global interrupt enable bit

}

void barcode_reset(void)
{
	barcode_length = 0;
	barcode_ready = 0;
}

unsigned char barcode_is_ready(void)
{
	return barcode_ready;
}

unsigned char barcode_get_length()
{
	return barcode_length;
}

/* interrupt entry function - barcode is the only module using interrupts */
void /*interrupt*/ barcode_interrupt(void)
{
	char data = RCREG;
	RCIF = 0;
	
	if (barcode_ready == 0)
	{
		if (data == '\r')
		{
			return;
		}
		else if (data == '\n')
		{
			barcode_ready = 1;
		}
		else 
		{
			global_barcode_buffer[barcode_length++] = RCREG;
		}
	}
}