//Patrick Jacks  
//12.1.08

//This program is designed for showing the extra credit project for 3 phase voltage generation at 60hz
//timer counters 0 & 1/3 are used
//
//HARDWARE SETUP
//0C0 - PB4 
//OC1A - PB5
//OC1B - PB6
//OC1C - PB7
//OC3A - PE3
//OC3B - PE4
//OC3C - PE5
//

#define F_CPU 16000000UL     //16Mhz clock
#define shoot_thru = 1      //Delay factor to prevent shoot thru
#include <avr/io.h>
#include <util/delay.h>
#include <avr/interrupt.h>

volatile uint16_t sin_index = 0;
const uint16_t sin_lookup[192*3] = {//SINE LOOKUP TABLE
0,0,346,
13,0,353,
26,0,359,
39,0,364,
52,0,370,
65,0,374,
78,0,379,
91,0,383,
104,0,386,
116,0,390,
129,0,392,
141,0,395,
153,0,397,
165,0,398,
177,0,399,
189,0,400,
200,0,400,
211,0,400,
222,0,399,
233,0,398,
244,0,397,
254,0,395,
264,0,392,
273,0,390,
283,0,386,
292,0,383,
301,0,379,
309,0,374,
317,0,370,
325,0,364,
333,0,359,
340,0,353,
346,0,346,
353,0,340,
359,0,333,
364,0,325,
370,0,317,
374,0,309,
379,0,301,
383,0,292,
386,0,283,
390,0,273,
392,0,264,
395,0,254,
397,0,244,
398,0,233,
399,0,222,
400,0,211,
400,0,200,
400,0,189,
399,0,177,
398,0,165,
397,0,153,
395,0,141,
392,0,129,
390,0,116,
386,0,104,
383,0,91,
379,0,78,
374,0,65,
370,0,52,
364,0,39,
359,0,26,
353,0,13,
346,0,0,
353,13,0,
359,26,0,
364,39,0,
370,52,0,
374,65,0,
379,78,0,
383,91,0,
386,104,0,
390,116,0,
392,129,0,
395,141,0,
397,153,0,
398,165,0,
399,177,0,
400,189,0,
400,200,0,
400,211,0,
399,222,0,
398,233,0,
397,244,0,
395,254,0,
392,264,0,
390,273,0,
386,283,0,
383,292,0,
379,301,0,
374,309,0,
370,317,0,
364,325,0,
359,333,0,
353,340,0,
346,346,0,
340,353,0,
333,359,0,
325,364,0,
317,370,0,
309,374,0,
301,379,0,
292,383,0,
283,386,0,
273,390,0,
264,392,0,
254,395,0,
244,397,0,
233,398,0,
222,399,0,
211,400,0,
200,400,0,
189,400,0,
177,399,0,
165,398,0,
153,397,0,
141,395,0,
129,392,0,
116,390,0,
104,386,0,
91,383,0,
78,379,0,
65,374,0,
52,370,0,
39,364,0,
26,359,0,
13,353,0,
0,346,0,
0,353,13,
0,359,26,
0,364,39,
0,370,52,
0,374,65,
0,379,78,
0,383,91,
0,386,104,
0,390,116,
0,392,129,
0,395,141,
0,397,153,
0,398,165,
0,399,177,
0,400,189,
0,400,200,
0,400,211,
0,399,222,
0,398,233,
0,397,244,
0,395,254,
0,392,264,
0,390,273,
0,386,283,
0,383,292,
0,379,301,
0,374,309,
0,370,317,
0,364,325,
0,359,333,
0,353,340,
0,346,346,
0,340,353,
0,333,359,
0,325,364,
0,317,370,
0,309,374,
0,301,379,
0,292,383,
0,283,386,
0,273,390,
0,264,392,
0,254,395,
0,244,397,
0,233,398,
0,222,399,
0,211,400,
0,200,400,
0,189,400,
0,177,399,
0,165,398,
0,153,397,
0,141,395,
0,129,392,
0,116,390,
0,104,386,
0,91,383,
0,78,379,
0,65,374,
0,52,370,
0,39,364,
0,26,359,
0,13,353,
};

ISR(TIMER2_COMP_vect){
	sin_index += 3;  //add three on interrupt
	sin_index %= 576; //make sure index does not exceed the array

OCR1A = sin_lookup[sin_index];
OCR1B = sin_lookup[(sin_index+1)];
OCR1C = sin_lookup[(sin_index+2)];

OCR3A = sin_lookup[sin_index];
OCR3B = sin_lookup[(sin_index+1)];
OCR3C = sin_lookup[(sin_index+2)];
}

int main()
{
//Timer Counter Setup
//
//Timer/Counter 1
TCCR1A = (1<<COM1A1) | (1<<COM1B1) | (1<<COM1C1) ;  //Set WGM = 8 and output compare mode
TCCR1B = (1<<WGM13) | (1<<CS10); //Clock select N=1, WGM = 8
//Setup output compare registers
OCR1A = sin_lookup[sin_index];
OCR1B = sin_lookup[(sin_index+1)];
OCR1C = sin_lookup[(sin_index+2)];
ICR1 = 400;

//Timer/Counter 3
TCCR3A = (1<<COM3A1) | (1<<COM3A0) | (1<<COM3B1) | (1<<COM3B0) | (1<<COM3C1) | (1<<COM3C0);  //Set WGM = 8 and output compare mode
TCCR3B = (1<<WGM33) | (1<<CS30); //Clock select N=1, WGM = 8
//setup output compare registers
OCR3A = sin_lookup[sin_index];
OCR3B = sin_lookup[(sin_index+1)];
OCR3C = sin_lookup[(sin_index+2)];
ICR3 = 400;
//Timer/Counter 2 Setup
//timer/counter 2 is used to update registers OCR1:3A:C to set pwm at proper value for the sin lookup table and magnitude
TCCR2 = (1<<WGM21) | (1<<CS21); //CTC and N = 8
OCR2 = 172;  //F = Fclk/(N*(OCR2+1)) Ns = 192  //86=120hz

//Syncronization of Timer Counter 3,2,1
SFIOR = (1<<TSM);
TCNT1 = 0x0000;
TCNT3 = 0x0000;
TCNT2 = 0x00;

//Interupt Mask
TIMSK = (1<<OCIE2);
//Interupt Enable
sei();

//Set output direction registers
DDRB = (1<<PB7)|(1<<PB6)|(1<<PB5);
DDRE = (1<<PE5)|(1<<PE4)|(1<<PE3);

//Turn on timers
SFIOR = 0; 
while(1){//do forever

}
} //main