testpwm.c

来自「c语言在LINUX平台下开发PWM驱动程序.可以实现波形的调整」· C语言 代码 · 共 48 行

/******************************* file : testpwm.c ******************************
                        Version :  1.0
                        Function:  The PWM driver test 
                        Auther:    BIT
                        11/2006
*******************************************************************************/
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <math.h>
#include "disp_pic.h"
/******************************************************************************
output a pwm wave
*******************************************************************************/
main()
{
	int fd;
	unsigned int pwm_data;
	unsigned char str_temp[32];
	unsigned char temp;

	printf("\n******************\n");	
	printf(" PWM Test Program.\n");
	printf("******************\n");
	fd=open("/dev/pwm",O_RDWR);
	if(fd<0)
	{
		printf("Can't open device file: pwm\n");
		perror("Open: ");
		exit(-1);
	}
	while(1)
	{
		printf("\n\n****************************************************\n");
		printf("Input the decimal of the PWM (0-4095) :\n");
		printf("--For example, if you input '654', then the H:L of the pwm output is (654 : 4095-654)\n");
	
                fgets(str_temp,32,stdin);
                pwm_data=atoi(str_temp);
				
		pwm_data&=0xfff;	
		printf("What you input is : 0x%x\n",pwm_data);
		ioctl(fd,0,pwm_data);
		
	}
}