//Grillzilla Transmit Unit

//Includes
#include<mega32.h>
#include<.\txrx.c>

//definitions
#define begin {
#define end }
#define data_length 2
#define tx_id 15
#define threshold 1000
//macros
#define int2fix(a)   (((int)(a))<<8)            //Convert char to fix. a is a char
#define fix2int(a)   ((signed char)((a)>>8))    //Convert fix to char. a is an int
#define float2fix(a) ((int)((a)*256.0))         //Convert float to fix. a is a float
#define fix2float(a) ((float)(a)/256.0)         //Convert fix to float. a is an int 

//defined constants


char data[data_length]; 
unsigned char packet_count, packetNum;
unsigned int time;
unsigned char temperature;
/* Faster version of A/D temp conversion
//variables
unsigned int multConst;
unsigned int slope;
unsigned int intercept;
//initializations
//multConst = 4*AVCC / 1024
//slope = -111.11 / 4
multConst = 0x0005;
slope = float2fix(-13.88875); 
intercept = int2fix(70);
//program code
temperature1 = fix2int((multfix(slope, multfix((multConst << 2),int2fix(ADCH >> 2))) + intercept) << 3);    
*/
// //==Fast fixed multiply=================================
// 
// int multfix(int a,int b)
// begin
//     #asm
//   ;******************************************************************************
// ;*
// ;* FUNCTION
// ;*	muls16x16_24
// ;* DECRIPTION
// ;*	Signed multiply of two 16bits numbers with 24bits result.
// ;* USAGE
// ;*	r31:r30:rxx = r23:r22 * r21:r20
// 
// ;******************************************************************************
//     push r20
//     push r21
//    
//     LDD  R22,Y+2  ;load a
// 	LDD  R23,Y+3 
// 	
// 	LD   R20,Y    ;load b
// 	LDD  R21,Y+1
// 	
// 	muls	r23, r21		; (signed)ah * (signed)bh
// 	mov		r31, r0         ;r18, r0
// 	mul		r22, r20		; al * bl
// 	mov     r30, r1         ;movw	r17:r16, r1:r0
// 	;mov     r16, r0
// 	mulsu	r23, r20		; (signed)ah * bl
// 	add		r30, r0         ;r17, r0
// 	adc		r31, r1         ;r18, r1
// 	mulsu	r21, r22		; (signed)bh * al
// 	add		r30, r0         ;r17, r0
// 	adc		r31, r1         ;r18, r1
// 	
// 	pop r21
// 	pop r20
//     #endasm
// end
// 

//**********************************************************
//timer 0 compare ISR
interrupt [TIM0_COMP] void timer0_compare(void)
begin      
	if(time<=threshold) time++; 
end  


//**********************************************************
void generate_data(char count)
begin
     	data[0] = count;       //packet count - cycles from 0-255
     	data[1] = temperature;
end                                                         


//**********************************************************
//initialization
void init()
begin
  
  //Used for LED array, output
	DDRC = 0xff;
	PORTC=0xff; //starting off

	//PORTD used for TX.
	//d7 led, d1 TX, d0,d2..6 unused
	DDRD = 0xff;
	PORTD.7=1; //turn d7 led on as power-on led
                          
  //set up timer 0  
  TIMSK=2;		//turn on timer 0 cmp match ISR 
  OCR0 = 249;  	//set the compare re to 250 time ticks
  //prescalar to 64 and turn on clear-on-match
  TCCR0=0b00001011;
  //initialize the transmit parameters	
  txrx_init(1,0,249,1);//TX only - 4000 baud - led on
  	
  //initialize variables
  time=0;
  packet_count=0;
  generate_data(packet_count);
 	
  //initialize ADC 
  //channel 7 / left adj / Aref=AVCC with capacitor at AREF Pin (default on Bruce Land's PCB!)
  //!!!*DIS*CONNECT Aref jumper if using STK-500!
  ADMUX = 0b01100111;   
  //enable ADC and set prescaler to 1/128*16MHz=125,000
  //and clear interupt enable
  //and start a conversion
  ADCSR = 0b11000111; 
 #asm ("sei");
 packetNum=0;
end                                                         




//**********************************************************
void main()
begin

init();

while(1)
begin 
       	if(time==threshold)
        begin
		        
		        //**A/D CONVERSION**
		        //get the A/D converter result, convert to fixed point
		        //see above for faster fixed point version if necessary
		        //the floating point version below has greater granularity
		        //-2.16577695 = (4*AVCC / 1024)*slope 
		        //slope = -111.11 (according to experimental data)
		        temperature = fix2int(float2fix(-2.16577695*ADCH + 560));
		        
		        //**DATA TRANSMISSION**
		        //create the packet
		        generate_data(packet_count);
                        //transmit the packet
                        tx_me(data, data_length, tx_id);
            
                        //**RESET FOR NEXT PACKET**
                        //reset time, flash the LED, increase packet count
                        time=0;
		        PORTD.7 = 0;  
		        packet_count++;
		        //start a new A/D conversion
		        ADCSR.6=1;
		               
        end
end //while
end //main