main._c

一个关于AVR单片机的例程

//ICC-AVR application builder : 2007-5-24 20:31:27
// Target : M16
// Crystal: 8.0000Mhz

#include <iom16v.h>
#include <macros.h>
#include "font.h"


#define  LCD_DC_PIN                 0x04  //  PB2
#define  LCD_CE_PIN                 0x02  //  PB1
#define  SPI_MOSI_PIN               0x20  //  PB5
#define  LCD_RST_PIN                0x01  //  PB0
#define  SPI_CLK_PIN                0x80  //  PB7

#define  X_Length  45
#define  X_Init    10
#define  Y_Init    2

/*--------------------------------------------------------------------------------------------------
                                 Public function prototypes
--------------------------------------------------------------------------------------------------*/
void LcdInit       ( void );
void LcdClear      ( void );

static void LcdSend    ( unsigned char, unsigned char);
static void Delay      ( void );
void LcdGotoXY         ( unsigned char, unsigned char );

unsigned int timer_count=0;

void port_init(void)
{
 PORTA = 0x00;
 DDRA  = 0x00;
 PORTB = 0x00;
 DDRB  = 0x00;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD  = 0x00;
}

//TIMER0 initialize - prescale:1
// WGM: Normal
// desired value: 32uSec
// actual value:  32.000uSec (0.0%)
void timer0_init(void)
{
 TCCR0 = 0x00; //stop
 TCNT0 = 0x00; //set count
 OCR0  = 0xFE;  //set compare
 TCCR0 = 0x01; //start timer
}

#pragma interrupt_handler timer0_comp_isr:20
void timer0_comp_isr(void)
{
 //compare occured TCNT0=OCR0
  TCNT0 = 0x00;
  timer_count++;
}
//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x02;  //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

void delay(void)  //延时
{ 
 unsigned int i=0;
 unsigned char j=0;
 for(i=1;i!=0;i++)
 {
   for(j=1;j!=0;j++)
    ;
 }
}

void Delay100us(unsigned char x)
{
	unsigned char i;          //4clock                   
	for(i=147;x!=0;x--)	
	while(--i);      //5 * i clock
}
void Delay1ms( unsigned int n)
{        
	for (;n!=0;n--){
		Delay100us(10);
	}
}
void Delay1s( unsigned int m)         //  m <= 6 ,when m==7, it is 1. 
{
	m=m*40;                
	for (;m!=0;m--){
		Delay100us(250);
	}
}


/*--------------------------------------------------------------------------------------------------
                                      Global Variables
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,10个
--------------------------------------------------------------------------------------------------*/
//字模 "FUCK JAPAN"
unsigned char const X_TAB[]  =    
{0x7E,0x0A,0x0A,0x0A,0x00,0x7E,0x40,0x40,0x7E,0x00,0x7E,0x42,0x42,0x42,0x00,0x7E,0x18,0x24,0x42,0x00,0x00,0x00,0x42,0x7E,0x02,0x00,0x7C,0x12,0x12,0x7C,
0x00,0x7E,0x0A,0x0A,0x0E,0x00,0x7C,0x12,0x12,0x7C,0x00,0x7E,0x08,0x10,0x7E};







////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////

/*--------------------------------------------------------------------------------------------------
  Name         :  LcdInit
  Description  :  Performs MCU SPI & LCD controller initialization.
  Argument(s)  :  None.
  Return value :  None.
--------------------------------------------------------------------------------------------------*/
void LcdInit( void )
{    
    //unsigned char Clear;
    //  Pull-up on reset pin，上电复位端口，此时为高，不复位；
    PORTB |= LCD_RST_PIN;

    //  Set output bits on port B,设置输出口；
    DDRB |= LCD_RST_PIN | LCD_DC_PIN | LCD_CE_PIN | SPI_MOSI_PIN | SPI_CLK_PIN;

    Delay();

    //  Toggle display reset pin.
    PORTB &= ~LCD_RST_PIN; //上电复位；
    Delay();
    PORTB |= LCD_RST_PIN;  //复位完；

    //  SPI初始化；Enable SPI port: No interrupt, MSBit first, Master mode, CPOL->0, CPHA->0, Clk/4
    SPCR = BIT(SPE)|BIT(MSTR); //使能SPI,主机模式；
    //SPSR = 0x00;  //似乎不用这几句也能正常运行；
    //Clear= SPSR;
    //Clear= SPDR;
    //  Disable LCD controller
    PORTB |= LCD_CE_PIN;       

    LcdSend( 0x21, 0 );  // LCD Extended Commands.
    LcdSend( 0xC8, 0 );  // Set LCD Vop (Contrast).
    LcdSend( 0x06, 0 );  // Set Temp coefficent.
    LcdSend( 0x13, 0 );  // LCD bias mode 1:48.
    LcdSend( 0x20, 0 );  // LCD Standard Commands, Horizontal addressing mode.
    LcdSend( 0x0C, 0 );  // LCD in normal mode.

    LcdClear();
   
}


/*--------------------------------------------------------------------------------------------------
  Name         :  LcdClear
  Description  :  Clears the display.
  Argument(s)  :  None.
  Return value :  None.
--------------------------------------------------------------------------------------------------*/
void LcdClear(void)
{
unsigned int i;

LcdSend(0x0c, 0); 
LcdSend(0x80, 0); //此时默认操作为清屏

for (i=0; i<504; i++)
LcdSend(0, 1); 
}



/*--------------------------------------------------------------------------------------------------
  Name         :  LcdGotoXY 设置块坐标
  Description  :  Sets cursor location to xy location corresponding to basic font size.
  Argument(s)  :  x, y -> Coordinate for new cursor position. Range: 1,1 .. 14,6
  Return value :  None.
--------------------------------------------------------------------------------------------------*/
void LcdGotoXY(unsigned char X, unsigned char Y)
{
LcdSend(0x40 | Y, 0); // column
LcdSend(0x80 | X, 0); // row
}

/*--------------------------------------------------------------------------------------------------
  Name         :  LcdSend
  Description  :  Sends data to display controller.
  Argument(s)  :  data -> Data to be sent
                  cd   -> Command or data (see/use enum)
  Return value :  None.
--------------------------------------------------------------------------------------------------*/
static void LcdSend (unsigned char data, unsigned char command)
{
PORTB &= ~LCD_CE_PIN ; // 使能LCD
if (command == 0)
PORTB &= ~LCD_DC_PIN ; // 传送命令
else
PORTB |= LCD_DC_PIN ; // 传送数据

SPDR = data; // 传送数据到SPI寄存器

while ((SPSR & 0x80) == 0); // 等待数据传送完毕

PORTB |= LCD_CE_PIN ; // 关闭LCD
}
/*--------------------------------------------------------------------------------------------------
  Name         :  Delay
  Description  :  Uncalibrated delay for LCD init routine.
  Argument(s)  :  None.
  Return value :  None.
--------------------------------------------------------------------------------------------------*/
static void Delay ( void )
{
    int i;
    for ( i = -12000; i < 12000; i++ );
}

void lcd_show(unsigned int r,unsigned int DOT)
{
 unsigned char tmp=0,i=0;
 if(r >1000)
 {
  tmp=r/1000;
  for(i=0;i<5;i++)
    LcdSend(FontLookup[tmp][i],1);
 }
 if(r >100)
 {
  tmp=(r%1000)/100;
  for(i=0;i<5;i++)
    LcdSend(FontLookup[tmp][i],1);
 }
 if(r >10)
 {
  tmp=(r%100)/10;
  for(i=0;i<5;i++)
    LcdSend(FontLookup[tmp][i],1);
 }
 
 tmp=r%10;
 
 for(i=0;i<5;i++)
    LcdSend(FontLookup[tmp][i],1);
 // 小数点
  for(i=0;i<5;i++)
    LcdSend(FontLookup[10][i],1);
 //
 for(i=0;i<5;i++)
    LcdSend(FontLookup[DOT][i],1);
 //K
  for(i=0;i<5;i++)
    LcdSend(FontLookup[11][i],1);
}


/*--------------------------------------------------------------------------------------------------
  Name         :  main
  Description  :  
  Argument(s)  :  
  Return value :  None.
--------------------------------------------------------------------------------------------------*/
/*
void main(void)
{  unsigned char X;  //v=0,按行显示，x对应某个bank(0~83)
   LcdInit();
  
   while(1)
  {
    LcdGotoXY(X_Init,Y_Init);
    for(X=0;X<X_Length;X++)LcdSend(X_TAB[X],1);
  }
}
*/

void main(void)
{
 unsigned int time1=0,time2=0;
 float RF=46.0,R=0.0;
 unsigned int R_TMP=0,DOT=0;
 timer_count=0;

 init_devices(); //全部输入，内部上拉

 DDRA |=(1<<2);
 PORTA |=(1<<2); //PA2 输出，完成充电
 Delay1ms(50);             //延时等待充满
 _NOP();
 DDRA &=~(1<<2); //输入，
 PORTA &=~(1<<2);
 
 timer0_init();
 DDRA |=(1<<1);  //
 PORTA &=~(1<<1); //PA1 输出低，完成放电
 while(PINA&(1<<2)); //等待，放电完成，PINA2被拉低
 TCCR0 = 0x00; //stop timer
 time1=timer_count; //记录标准电阻的放电时间


 timer_count=0;
 init_devices(); //全部输入，内部上拉
 DDRA |=(1<<2);
 PORTA |=(1<<2); //PA2 输出，完成充电
 Delay1ms(50);             //延时等待充满
 _NOP();
 DDRA &=~(1<<2); //输入
 PORTA &=~(1<<2); //清内部上拉
 
 timer0_init();
 DDRA |=(1<<0);  //
 PORTA &=~(1<<0); //PA0 输出低，完成放电
 while(PINA&(1<<2)); //等待，让电完成，PINA2被拉低
 TCCR0 = 0x00; //stop timer
 time2=timer_count; //计算待测电阻的时间
 
 //开始计算阻值
 R=RF*time2/time1;
 
 //R=1234;
 LcdInit();
 LcdGotoXY(X_Init,Y_Init);
 
 R_TMP=R;
 DOT=(R-R_TMP)*10;
 lcd_show(R_TMP,DOT);
 
 while(1)
 ;
}