main.c

运行在s3c2410开发实验源代码

/************************************************
*	by zou jian guo<[e-mail]>	
*		2004.9.27 14:30			
*						
*   the driver is s3c2410_da_max504.c in drivers/char
*************************************************/

#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <sys/ioctl.h>

#define Max504_FULL			4.096f

static int da_fd = -1;

void Delay(int t)
{
	int i;
	for(;t>0;t--)
		for(i=0;i<400;i++);
}
/****************************************************************/
int main(int argc, char **argv)
{
	float v;
	unsigned int value;
 	char *DA_DEV="/dev/da/0";

	if(argc < 2){
		printf("Error parameter\n");
		return 1;
	}
	sscanf(argv[1], "%f",&v);	
	if(v<0 || v>Max504_FULL){
		printf("DA out must between: 0 to %f\n", Max504_FULL);
		return 1;
	}
	if(argc==3)DA_DEV="/dev/da/1";
	if((da_fd=open(DA_DEV, O_WRONLY))<0){
		printf("Error opening %s spi device\n", DA_DEV);
		return 1;
	}
	
	value=(unsigned int)((v*1024.0f)/Max504_FULL);
	write(da_fd,&value,4);
	
	close(da_fd);                                                         
	printf("Current Voltage is %f V\n", v);
	return 0;
}