#include <stdio.h>
#include <reg51.h>
#include <irq52.h>
#include <string.h>

void DelayT0(unsigned long count);						//delay "10" 10us


void WriteData(unsigned char cData);						//datem am lcd
void WriteInstr(unsigned char cInstr);						//befehl an lcd
void DisplayBusy(void);							//busy flag lcd abfragen
void InitLcd(void);								//lcd initialisieren
void WriteLine(unsigned char *text,unsigned char cursor);	//schreiben einer ganzen linie

void ReadAD(void);											//spannungswerte lesen
void ReadADS(void);											//strom werte lesen

void ShowCounts(float ergebnis);							//anzeige auf display
void display(float val, uchar *ptr );						//float to asci

void get_gray_delta( void );


//***************lcd ports****************

#define LCDPORT P2

#define ENA		P1_B0											//enable lcd
#define RW		P1_B1											//schreiben oder lesen lcd
#define RS		P1_B2											//befehl senden oder lesen lcd

#define BF		P2_B7


//*****************da ports**************

//spannung
#define DATA	P0_B7
#define CLK		P0_B6
#define CS		P0_B5

//strom
#define DATAS	P0_B1
#define	CLKS	P0_B3
#define CSS		P0_B0

//*****************encoder****************
#define GRAY_A	P1_B6
#define GRAY_B	P1_B7

//lcd variablen**************************

#define clear_LCD		0x01
#define home_LCD		0x02
#define set_LCD			0x38
#define LCD_off			0x0E
#define entry_mode		0x06		
#define cursor_off		0x0C
#define cursor_blink	0x0F


#define EZeile		0x80									//1.Zeile anfang
#define ZZeile		0xC0									//2.Zeile anfang




//lcd text*****************************************


code char welcome1[]="Test Programm   ";
code char welcome2[]="                ";
code char leer[]	="                ";
code signed char graytab[] = { 0,1,-1,0, -1,0,0,1, 1,0,0,-1, 0,-1,1,0 };

near char buf[]		= "";									//buffer für int zahl ins ram speichern;	
near char ComChar[] = "";
near float AnalogBuf=0;										//buffer für analogwert wandler	spannung

near signed char zaehler=100;

near signed char gray_width;
near signed char graycount;


IRQ_VECTOR(timer0int,TIMER0)

void timer0int (void) interrupt  {
	
	static unsigned  char graycode = 0;

	if( GRAY_A )
		 graycode |= 0x10;                // new state to bit 3, 2
	if( GRAY_B )
		 graycode |= 0x20;
  
  graycode >>= 2;          				  // old state to bit 1, 0
  graycount += graytab[graycode];		  // +/- 1 if state change
}



void main(void)
{
	
	
	unsigned char i;
	unsigned char az_zeichen;
	

  
  EA   = 0;	
  

  // Set up UART
  PCON|=128;							// Baudrate double
  SCON = 126;							// 8 Bit UART - PC-compatible, TI-FLAG set!
  TH1=256-(XTAL/(192L*BAUDRATE));		// Calculate baudrate divisor
  TMOD=32;								// use timer 1 as baudrate generator
  TCON=64;								// dto.	


  // Init Timer0 
  TMOD &= 0xF0;	 // TMOD Timer 0: 8 bit counter
  TMOD |= 0x02;	 // 8 Bit Reload Mode
  TH0 = 200;	 //reload wert
  ET0  = 1;		 // Enable timer interrupt
  TR0  = 1;		 // Start timer

  
	DelayT0(10000);									 //warten bis alle spannung stabil sind
	
	InitLcd();
	WriteInstr(0x0C);								//cursor off;
	
	WriteLine(welcome1,EZeile);						//begrüssungstext
	WriteLine(welcome2,ZZeile);
	DelayT0(50000);
	
	EA = 1;


  for(;;){
	

	ReadAD();

	printf("%fA",AnalogBuf);
	get_gray_delta();
	zaehler = gray_width;
	
	az_zeichen=sprintf(buf,"%d",zaehler);	//int to string
	
	WriteInstr(0xC0);						//display löschen
	for(i=0;i < (az_zeichen+1);i++){
		WriteData(leer[i]);
	}
	
	WriteInstr(0xC0);
	for(i=0;i< az_zeichen;i++){
		WriteData(buf[i]);
	}
	
	
	DelayT0(10000);		
	
  }
}


void get_gray_delta( void )					// get counts after last call
{
  signed char val;
  EA = 0;
  val = graycount;
  graycount = 0;
  EA = 1;
  gray_width =  val;
}