/************************************************************************
* Term:   Fall 2003
* Course: ECE 473
* Name:	  Olamide Adabonyan / Philip Lechowicz
* E-mail: o_mide@yahoo.com / phillech@aol.com
*
* REVISION HISTORY
*
* First Draft: Oct 18, 2002
*   		   -LEDs not lighting up correctly
*
* Date Submitted: 	?/??/02
* Demo Approval: 	________
************************************************************************/

#include <hc11.h>
#include <stdio.h>
#include <vector.h>

#define endProg() asm("swi")
#define enableInt() asm("cli")
#define disableInt() asm("sei")

#define fivePercent 1000

short ontime, offtime;
char motorStatus;

void initBoardB(void);
void OC1handler(void);

/*******************************************************
Name: initBoardB
Purpose: initilize slave board (boardB)
		 - turn LEDs off
		 - turn motor on with PWM duty cycle of 50%
		 - configure SPI
		 - set up OC1
Inputs: none
Outputs: none
********************************************************/
void initBoardB()
{
 	char dummy;
	disableInt(); //disable interrupts
	
	PORTA = 0x00;
	ontime = 10000;
	offtime = 10000;
	
	//??? SPI Configuration... [master basically does everything]
	SPCR = 0x40;
	DDRD = 0x04;
	dummy = SPSR;
	dummy = SPDR;
	
	TOC1vector= &OC1handler;
	TMSK1 = 0x80;
	TFLG1 = 0x80;
	TOC1 = TCNT + ontime;
	
	enableInt(); //enable interrupts
}


/*******************************************************
Name: OC1handler
Purpose: control ontime/offtime for motor (using PWM)
Inputs: none
Outputs: none
********************************************************/
#pragma interrupt_handler OC1handler()
void OC1handler()
{
	if (ontime >= 20000)
	{
		ontime = 20000;
		offtime = 0;
		TOC1 = TOC1 + ontime;
		PORTA |= 0x60;
		//printf("max PWM...\n");	//debugger
	}
	else if (offtime >= 20000)
	{
		offtime = 20000;
		ontime = 0;
		TOC1 = TOC1 + offtime;
		PORTA = 0x10;
		//printf("min PWM...\n"); //debugger
	}	
	else if (motorStatus == 1)
	{
		motorStatus = 0;
		TOC1 = TOC1 + offtime;
		PORTA ^= 0x40;
	}
	else if(motorStatus == 0)
	{
		motorStatus = 1;
		TOC1 = TOC1 + ontime;
		PORTA ^= 0x40;
	}
	
	TFLG1 = 0x80;
}


/*******************************************************
Name: Main
Purpose:
		- Initialize system by calling initBoardB() function
		- Wait for SPI messages and calls other functions
		   to do specific tasks, depending on message recieved.
		- Controls state of LEDs
Inputs: none
Outputs: none
********************************************************/
main()
{
 	char dummy, masterSignal;
	
	initBoardB();
	
	while(1)
	{
		//dummy = SPSR;
		//dummy = SPDR;
		
		while ((SPSR & 0x80) == 0)
		{
			/*check for collision error
			if((SPSR & 0x40) != 0)
			{
				dummy = SPSR; //this clears collision error flag (WCOL) together with next step
				dummy = SPDR; //read corrupted data
				printf("\ncollision error\n");
			}*/
		}
		
		//clear SPIF bit in SPSR (SPI transfer complete flag)
		dummy = SPSR; 			
		masterSignal = SPDR;
		
		if (masterSignal == 0x00)
		{
			if (offtime < 0)
				offtime = 0;
			ontime -= fivePercent;
			offtime += fivePercent;
			
			PORTA |= 0x10;
			if ((PORTA & 0x20) != 0)
				PORTA ^= 0x20;

			printf("ontime %d, offtime %d\n", ontime, offtime); //debugger
			printf("red PWM\n");
		}
		else if (masterSignal == 0x01)
		{
			if (ontime < 0)
				ontime = 0;
			ontime += fivePercent;
			offtime -= fivePercent;
			
			PORTA |= 0x20;
			if ((PORTA & 0x10) != 0)
				PORTA ^= 0x10;
			
			printf("ontime %d, offtime %d\n", ontime, offtime); //debugger			
			printf("inc PWM\n"); 
		}
/*		else
		{
		 	printf("wrong input recieved");
		}*/
	}
			  
	//endProg(); //4 debugging...
}

/*
	while ((SPSR & 0x80) == 0)
		{
			//check for collision error
			if((SPSR & 0x40) != 0)
			{
				dummy = SPSR; //this clears collision error flag (WCOL) together with next step
				dummy = SPDR; //read corrupted data
			}
			printf("just looping");
		}
	//clear SPIF bit in SPSR (SPI transfer complete flag)
	dummy = SPSR; 			
	masterSignal = SPDR;
	if (masterSignal == 1)
	{
		while(1)
				printf("yah, i got a 1");
	}
	else
	{
		while(1)
		{
		 dummy = masterSignal;
		 printf("nada, didnt get a 1 \n dummy signal = %d", dummy);
		}
	}
*/