uart-lednum._c

这是关于AVR单片机学习的初步开发

//ICC-AVR application builder : 2005-3-8 下午 04:53:49
// Target : M8
// Crystal: 11.059Mhz

#include <iom8v.h>
#include <macros.h>

//lednum全局变量
char lednum = 0;
char lednum1 = 0x3f;
char lednum2 = 0x06;
char lednum3 = 0x5b;
char lednum4 = 0x4f;
//码表
char num[10] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};

//uart全局变量
char uart_count=0;
char led_sel = 1;

void port_init(void)
{
 PORTB = 0xFF;
 DDRB  = 0xFF;
 PORTC = 0x7F; //m103 output only
 DDRC  = 0x7F;
 PORTD = 0x00;
 DDRD  = 0xFF;
}

//TIMER0 initialisation - prescale:1024
// WGM: Normal
// desired value: 20mSec
// actual value: 19.908mSec (0.5%)
void timer0_init(void)
{
  TCCR0 = 0x00; //stop
 TCNT0 = 0x29; //set count
 TCCR0 = 0x04; //start timer
}

#pragma interrupt_handler timer0_ovf_isr:10
void timer0_ovf_isr(void)
{
 TCNT0 = 0x29; //reload counter value
 TCCR0 = 0x04; //start timer
 
 PORTB |= 0x30;
 PORTC |= 0x30;
 if(lednum == 0)	//更新PB4数码管；
 {	PORTB &= ~0x10;
	PORTD = lednum4;
 }
 else if(lednum ==1)	//更新PB5数码管；
 {	PORTB &= ~0x20;
	PORTD = lednum3;
 }
 else if(lednum ==2)	//更新PC4数码管；
 {	PORTC &= ~0x10;
	PORTD = lednum2;
 }
 else 	//更新PC5数码管；
 { 	PORTC &= ~0x20;
	PORTD = lednum1;
 }

lednum++;
while(lednum >= 4) lednum = lednum - 4;
 
}

//UART0 initialisation
// desired baud rate: 9600
// actual: baud rate:9600 (0.0%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
 UCSRB = 0x00; //disable while setting baud rate
 UCSRA = 0x00;
 UCSRC = 0x86;
 UBRRL = 0x47; //set baud rate lo
 UBRRH = 0x00; //set baud rate hi
 UCSRB = 0x98;
}

#pragma interrupt_handler uart0_rx_isr:12
void uart0_rx_isr(void)
{
 //uart has received a character in UDR
 char temp;
 temp = UDR;
 if(uart_count == 0)
 {	led_sel = temp;
	uart_count ++;
 }
 else
 {	 uart_count = 0;
 	 if(led_sel == 1)
	 	lednum1=temp;
	 else if(led_sel == 2)
	 	lednum2 = temp;
	 else if(led_sel == 3)
	 	lednum3 = temp;
	 else
	 	lednum4 =temp;
 }
}


//call this routine to initialise all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 timer0_init();
 uart0_init();
 
 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x01; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialised
}




//自定义函数
void delay(void)
{
 unsigned int i,j,z;
 for(i=0;i<10000;i++);
 {	for(j=0;j<10000;j++)
 	{	for(z=0;z<100;z++);}
 }
}

void main(void)
{
  
 init_devices();
 
 lednum1 = num[0];
 lednum2 =num[1];
 lednum3 = num[2];
 lednum4 = num[3]; 
 while(1)
 {;  
 } 
}