// Copied from Rab Hart's code that was
//Shamelessly copied and mofied from Neil Gershenfeld's for purposes of instruction.

//This cycles the color pattern of LEDs in response to button press
//For the ATTINY44

// Button  PA2 (pin 8).
// RED     PA7 (pin 5).
// GREEN   PA6
// BLUE    PA5



#include <avr/io.h>       //this includes all definitions of registers and bits of registers, including pins and port names.

#define output(directions,pin) (directions |= pin) // set port direction for output
#define input(directions,pin) (directions &= (~pin)) // set port direction for input
#define set(port,pin) (port |= pin) // set port pin
#define clear(port,pin) (port &= (~pin)) // clear port pin
#define pin_test(pins,pin) (pins & pin) // test for port pin
#define bit_test(byte,bit) (byte & (1 << bit)) // test for bit set

#define input_port PORTA		   // The button is on port A
#define input_direction DDRA	 //  DDRA defines input/output for port A
#define input_pin (1 << PA2)	 //  The button is on pin 5 of port A    (1<<PA5) = (1<<5) = 0b00100000
#define input_pins PINA			   //  PINA is the register that is read to detect input high or low.
#define output_port PORTA		   //  port B will be used for the LED
#define output_direction DDRA	 // DDRB defines input/output for port B
#define output_red (1 << PA7)  //
#define output_grn (1 << PA6)
#define output_blu (1 << PA5)
const int i = 0;

int main(void) {
   //
   // main function.
   //

   // initialize pins

   output(output_direction, output_pin);        //  set output for LED pin.
   set(input_port, input_pin);                  // turn on internal pull-up
   input(input_direction, input_pin);           // set button pin for input.

   // main loop

   while (1) {

    if (pin_test(input_pins,input_pin))         //test button pin.
      if(i==0){
        set(output_port,output_red);
        i++;
      }
      if(i==1){
        set(output_port,output_grn);
        clear(output_port,output_red);
        i++;
      }
      if(i==2){
        set(output_port,output_blu);
        clear(output_port,output_grn);
        i++;
      }
      if(i==3){
        set(output_port,output_red);
        i++;
      }
      if(i==4){
        set(output_port,output_grn);
        i++;
      }
      if(i==5){
        clear(output_port,output_blu);
        i++;
      }
      if(i==6){
        clear(output_port,output_red);
        i++;
      }
      if(i==7){
        clear(output_port,output_grn);
        i=0;
      }
    else
                      //  if button isn't pushed, stay how you are!

      }
   }