//-----------------------------------------------------------------
// Code for Attinty2313 Mood Light SKull Lantern by_MAx
//
// fast PWM will be used for separate dimming of RGB LED's channles
// sorry I will not explain how Pulse With Modulaton works
// many sources are available on internet
// one example: www.atmel.com/images/doc2542.pdf
//-----------------------------------------------------------------

#include <avr/io.h> //needed for pin defines
#include <util/delay.h> //needed for delay function
#include <stdlib.h> //needed for random function

// ----- ===== ( defines for human readble code ) ===== -----
// many defines were made to make code self explanatory

#define mainProgram int main(void)
#define integer uint8_t
#define setBit(x) |=1<<x
#define runForever while(1)

// ----- ===== ( definitions from Attinty2313 manual ) ===== -----
//memmory addreses for Timer/Counter Control Register 
#define timerControl_0 TCCR0A
#define timerControlScaling_0 TCCR0B
#define timerControl_1 TCCR1A
#define timerControlScaling_1 TCCR1B

//bit names for Timer/Counter Control Register 

	//Waveform Generation Mode Fast PWM needs two bits set
#define FastPWM_00 WGM00
#define FastPWM_01 WGM01
#define FastPWM_10 WGM10
#define FastPWM_11 WGM11

	//Compare Output Mode For Fast PWM Mode "Clear OC0 on compare match"
	//we need separate ones for every pin
	//pins named by LED's RGB channels
#define compareMatchRed COM1B1
#define compareMatchGreen COM0A1
#define compareMatchBlue COM1A1
	//Clock Select Bit Description
#define NoPrescale_0 CS00
#define NoPrescale_1 CS10

//memmory addreses for Data Direction Register 
	//sets if pins is output or input
#define dataDirection DDRB 

//bit names for Data Direction Register 
#define pinRed PB4
#define pinGreen PB2
#define pinBlue PB3

//memmory addreses for output compare registers
	//integer values assinged to them will result in brightness of LED RGB channel
#define redBrightness OCR1B
#define greenBrightness OCR0A
#define blueBrightness OCR1AL


// ----- ===== ( function prototypes ) ===== -----
uint8_t map(uint8_t a,uint8_t b,uint8_t position);
void hueToRgb(uint8_t *color,uint8_t hue);

mainProgram{
	//seting variables to initial values
	integer timer;
	// define array. syntax explanation: 
	// typeOfArray nameOfArray [membersInArray]={valuesOfMembers};
	integer oldColor[3]={0,0,0};
	integer targetColor[3]={50,0,255};
	
	//now set configure fast PWM using bits we defined
	timerControl_0 setBit( FastPWM_00 );
	timerControl_0 setBit( FastPWM_01 );
	timerControl_0 setBit( compareMatchGreen );
	timerControlScaling_0 setBit( NoPrescale_0 );
	
	timerControl_1 setBit( FastPWM_10 );
	timerControl_1 setBit( FastPWM_11 );
	timerControl_1 setBit( compareMatchBlue );
	timerControl_1 setBit( compareMatchRed );
	//timerControl_1|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11)|(1<<WGM10);
	timerControlScaling_1 setBit( NoPrescale_1 );

	// set pins to output
	dataDirection setBit( pinRed );
	dataDirection setBit( pinGreen );
	dataDirection setBit( pinBlue );
	
    runForever{
        for (timer = 0; timer < 255; ++timer)
        {
            //every frame set the brightness for every channel using interpolation funcion
			redBrightness   = map( oldColor[0], targetColor[0], timer);
            greenBrightness = map( oldColor[1], targetColor[1], timer);
			blueBrightness  = map( oldColor[2], targetColor[2], timer);
            // delay so as to make the user "see" the change in brightness
            _delay_ms(100);
        }
		// pause for mood to settle
		_delay_ms(1000); 
		// LED color is now set to targetColor, so it becomes old
		oldColor[0]=targetColor[0];
		oldColor[1]=targetColor[1];
		oldColor[2]=targetColor[2];
		
		//get random hue and convert it to targetColor's RGB values
		hueToRgb(targetColor,rand()%252);
    }
}
//interpolation functon
uint8_t map(uint8_t a,uint8_t b,uint8_t x){
	return((a*(255-x)+b*x)/255.);
}
//convertion funcion hue to RGB
void hueToRgb(uint8_t *color,uint8_t hue){
	if(hue<42){
		color[0]=255;
		color[1]=6*hue;
		color[2]=0;
	}else if(hue<84){
		color[0]=255-6*hue;
		color[1]=255;
		color[2]=0;
	}else if(hue<126){
		color[0]=0;
		color[1]=255;
		color[2]=6*hue;
	}else if(hue<168){
		color[0]=0;
		color[1]=255-6*hue;
		color[2]=255;
	}else if(hue<210){
		color[0]=6*hue;
		color[1]=0;
		color[2]=255;
	}else{
		color[0]=255;
		color[1]=0;
		color[2]=6*hue;
	}
}