#include <mega32.h>
#include <stdio.h>
#include <stdlib.h>

#define begin {
#define end }
//debounce state
#define NoPush 1
#define MaybePush 2
#define Pushed 3
#define MaybeNoPush 4


//direction
#define forward 1
#define reverse 0
//steering

// Declare your global variables here
unsigned char command,speedin,speedmag,direction,steering,noturn,switchin;
unsigned char light,left,right;
unsigned char PushState1,PushFlag1,PushState0,PushFlag0,PushStateL,PushStateR;

interrupt [USART_TXC] void uart_tran(void)
{
     UDR=command;
}

void initialize(void)
{

	DDRA=0x00;

	//output LED 
	PORTB=0xff;
	DDRB=0xff;

	//switch input
	DDRC=0x00;

	//USART communication jumpers
	//PORTD=0xff;
	DDRD=0xff;

	PushState0 = NoPush; //light button state	
	PushStateL = NoPush; //left button state	
	PushStateR = NoPush; //right button state

	light=0;

	//USART setting
  	UCSRA = 0x00;
  	UCSRB = 0x08;
  	UCSRC = 0x36;

   	//2400 baud
    UBRRH = 0x01;
    UBRRL = 0xa0;

    SFIOR=0x00;
    ADMUX=0x20;

	//allows the receiver to adjust the gain
   	command=0x55;
  	putchar(command);
   	putchar(command);
  	putchar(command);
  	putchar(command);
  	putchar(command);
  	putchar(command);
  	putchar(command);
  	putchar(command);

     #asm ("sei");

}

//debounce left button
void debounce_left ()
{
  switch (PushStateL)
  begin
     case NoPush:
        if (~PINC.3 == 1) PushStateL=MaybePush;
        else PushStateL=NoPush;
        break;
     case MaybePush:
        if (~PINC.3 == 1)
        begin
           PushStateL=Pushed;
           left=1;
        end
        else PushStateL=NoPush;
        break;
     case Pushed:
        if (~PINC.3 == 1) PushStateL=Pushed;
        else PushStateL=MaybeNoPush;
        break;
     case MaybeNoPush:
        if (~PINC.3 == 1) PushStateL=Pushed;
        else
        begin
           PushStateL=NoPush;
           left=0;
        end
        break;
  end
}

//debounce right button
void debounce_right()
{
  switch (PushStateR)
  begin
     case NoPush:
        if (~PINC.2 == 1) PushStateR=MaybePush;
        else PushStateR=NoPush;
        break;
     case MaybePush:
        if (~PINC.2 == 1)
        begin
           PushStateR=Pushed;
           right=1;
        end
        else PushStateR=NoPush;
        break;
     case Pushed:
        if (~PINC.2 == 1) PushStateR=Pushed;
        else PushStateR=MaybeNoPush;
        break;
     case MaybeNoPush:
        if (~PINC.2 == 1) PushStateR=Pushed;
        else
        begin
           PushStateR=NoPush;
           right=0;
        end
        break;
  end
}

//debounce light button
void debounce_light (void)
{

  switch (PushState0)
  begin
     case NoPush:
        if (~PINC.1 == 1) PushState0=MaybePush;
        else PushState0=NoPush;
        break;
     case MaybePush:
        if (~PINC.1 == 1)
        begin
           PushState0=Pushed;
           PushFlag0=1;
        end
        else PushState0=NoPush;
        break;
     case Pushed:
        if (~PINC.1 == 1) PushState0=Pushed;
        else PushState0=MaybeNoPush;
        break;
     case MaybeNoPush:
        if (~PINC.1 == 1) PushState0=Pushed;
        else
        begin
           PushState0=NoPush;
		   //turns the light off if it is on, turns the light on if it is off
           if (PushFlag0) light=~light;	
           PushFlag0=0;
        end
        break;
  end
}



void main(void)
{
      initialize();

      while (1)
      {

           UCSRB=0x48;		//enable transmit complete interrupt
      	   ADMUX=0x20;	   //left adjusted and ADC0
     	   ADCSR = 0xc7;  //ADC enable and start conversion

     	   debounce_left ();
     	   debounce_right ();


     	   //encode steering
    	   if (left==right) command=command | 0x04;  //noturn if both button pressed
    	   else
    	   {		
			   command = command & 0xfb;				//turn 
    		   if (left) command = command | 0x08 ;      //direction is left
    		   else command = command & 0xf7;              //direction is right
    	   }

    	   debounce_light ();     

		   //encode light 	
    	   if (light) command=command | 0x40;
    	   else command = command & 0xbf;


     	   while (ADCSR.4==0)
     	   {    //wait if A/D conversion had not finished
           }

		   speedin = ADCH; //update speed input from ADC
           
           //encode speed
           if (speedin > 0xa3)
           {
                 //direction=forward;
                command = (command | 0x10);
				//encode speed magnitude
                if (speedin < 0xcd) speedmag=0;
             	else if (speedin < 0xef) speedmag=2;
             	else speedmag=3;
             	PORTB.0=1;
           }
           else if (speedin < 0x67 )
           {
             	  //direction=reverse;
                 command = (command & 0xef);
				 //encode speed magnitude
                 if (speedin > 0x3f) speedmag=0;
                 else if (speedin > 0x0d) speedmag=2;
                 else speedmag=3;
                 PORTB.0=1;
           }
		   else
		   {
		   		speedmag=1;
     			PORTB.0=0;		//turn on the light at the controller
		   }
     	   command = (command & 0xfc) | speedmag ;	

      }
}