main.c

基于MEGA128的双通道AD转换例程序

/************************************************
文件：main.c
用途：
注意：内部8M晶振
创建：2008.4.1
修改：2008.4.1
Copy Right  (c)  www.avrvi.com  AVR与虚拟仪器
************************************************/

#include "config.h"
float adc_result;

void adc_init(void)
{
 ADCSRA = 0x00; //disable adc
 ADMUX = (1<<REFS0)|(1<<ADLAR);
 ACSR = (1<<ACD);
 ADCSRA = (1<<ADEN);
}

void get_adc(unsigned adc_channel)
{
 unsigned int value=0,i;
 
 adc_init();
 ADMUX += adc_channel;
 
 for(i=0;i<4;i++)
 {
  ADCSRA |= (1<<ADSC); 
  delay_nus(100);
  value += ADCH;
 }
 
 value >>= 2;
 
 adc_result=(value*4.97)/256;
}

void main(void)
{ 
 unsigned char *adc_str="The adc result of channel 0 is : 2.031 V\n\n",i=0;
 CLI();
 Com_init();
 SEI();
 while(1)
 {
  get_adc(i);
  adc_str[26]=i+0x30;
  adc_result *= 1000;
  adc_str[33]=(unsigned int)adc_result/1000+0x30;
  adc_str[35]=((unsigned int)adc_result%1000)/100+0x30;
  adc_str[36]=((unsigned int)adc_result%100)/10+0x30;
  adc_str[37]=(unsigned int)adc_result%10+0x30;
  
  Com_putstring (adc_str,41,&RTbuf_UART0);
  i++;
  if(i>1) i=0;
  
  delay_nms(300);
 }
}