ad-test.c

这是pxa270的ADC驱动程序

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

#include "ad.h"

#define AD_DEV "/dev/ad/0"

static int fd_ad = -1;

int main (int argc, char *argv[])
{
	unsigned short data;

	int ret;
	int read_len;
	int n_channel_no = 0;
	unsigned short n_channel0_value = 0;
	unsigned short n_channel1_value = 0;

	char *ad_dev = NULL;

	fd_ad = open(AD_DEV, O_RDONLY);
	if (fd_ad < 0) {
		printf("ERR: opening dev:%s \n", ad_dev);
		return -1;
	}

	printf("MagicARM270 AD Test Program is Now running\n");
	while (1) {
		n_channel_no = 2;
		if ( ioctl(fd_ad, AD_SET_CHANNEL, n_channel_no) < 0 ) {
			printf("ioctl set channel %d failed\n", n_channel_no);
		}
		read_len = read(fd_ad, &data, sizeof(data));
		if (read_len < 0) {
			printf("error happens reading channel %d\n", n_channel_no);
			continue;
		}
		n_channel0_value = data;

		n_channel_no = 3;
		if ( ioctl(fd_ad, AD_SET_CHANNEL, n_channel_no) < 0 ) {
			printf("ioctl set channel %d failed\n", n_channel_no);
		}
		read_len = read(fd_ad, &data, sizeof(data));
		if (read_len < 0) {
			printf("error happens reading channel %d\n", n_channel_no);
			continue;
		}
		n_channel1_value = data;

		printf("w1 = %d mV, w2 = %d mV\n", n_channel0_value, n_channel1_value);
		usleep(500000);		// sleep 0.5 s 
	}
	close(fd_ad);
	return(0);
}