usr.c

来自「扬创s3c2410adc电压采集程序」· C语言 代码 · 共 35 行

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#define ADC_DEV  "/dev/adc"
static int adc_fd=-1;
static int GetADresult(int channel)
{
 int data;
 read(adc_fd, &data, sizeof(data));
 return data;
}
int main(void)
{
 int i;
 float d;
 if((adc_fd=open(ADC_DEV, O_RDWR))<0){
  printf("Error opening %s adc device\n", ADC_DEV);
  return -1;
 }
                                                                          
 for(i=0;i<=100;i++){
   d=((float)GetADresult(i)*3.3)/1024.0;
   printf("a%d=%8.4f\t",i,d);
   printf("\n");
   sleep(1);
   printf("\r");
  
 }
 close(adc_fd);
 return 0;
}