#define F_CPU 3333333UL


#include <avr/io.h>
#include <util/delay.h>
#include <avr/interrupt.h>


#define LED1 4 // port D, connected to WO4
#define LED2 5 // port D, connected to WO5




/*
    In this exercise, you will use PWM to control the brightness of LEDs
    Once we have PWM set up, controling the brightness is super easy!
*/

int main(void)
{
	//Set up the leds and buttons. You might want to copy this from previous exercises.
	
	/*We will be using timer 1 in split (not single) mode. We use split to get access to WO4 and WO5, see Figure 19-13.
	  It is highly recommended that you read chapter 19.3.3.4 and 19.3.3.6 in the datasheet. 
	  There you will find a sub-chapter on the single-slope PWM we will be using.
	*/
	
	//First, enable the timer
	
	//Set the mode of the timer to split slope PWM 
	
	//We have to override the normal pin opperation so the PWM is pushed directly to the pin
	//Hint: WO4 and WO5 are connected to leds. We need to override them to get the PWM out.
	
	
	
	/*Timer A is a 16 bit timer.
	When we use split mode, this will be split into two 8 bit timers. This will give us a frequency of 25Hz/2, we can see it flicker.
	  By lowering the period, (PER) we get higher frequency at the cost of lower resolution. (Since in split mode, we must use HPER or LPER.)
	*/
	
	//Set the period to 0xff bit. (What frequency does this give?)
	
	
	//We can now control the PWM duty cycle by simply writing values to the CMP0 and CMP1 registers.
	TCA0.SPLIT.HCMP1 = 0x00; //Max brightness (Leds are inverted)
	TCA0.SPLIT.HCMP2 = 0xff; //Min brightness (Leds are inverted)
	
	
    while(1){
		
		/*Have some fun with the leds. Examples:
		  Have them fade between max and min
		  Have them fade in a pattern (Heartbeat?) 
		  Change the brightness based on buttons

		*/
		
    }
}