dm6430-user-timer.c

rt 6430 采集卡 linux下驱动源代码

/*
	FILE NAME: dm6430-user-timer.c

	FILE DESCRIPTION: User timer sample program

		This program sets up the User Timer to generate interrupts at
		a selected rate.  The program polls the value of the
		interrupt counter for the appropriate interrupt circuit and,
		when it changes, performs an A/D conversion.  The sampled data
		is printed on the screen.

	PROJECT NAME: Linux DM6430 Driver, Library, and Example Programs

	PROJECT VERSION: (Defined in README.TXT)

	Copyright 2004 RTD Embedded Technologies, Inc.  All Rights Reserved.
*/


#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/poll.h>
#include <unistd.h>

#include <dm6430lib.h>


char *program_name_p;


static void
usage(void) {
    fprintf(
	stderr,
	"\n"
        "Usage: %s MINOR_NUMBER"
        "\n",
	program_name_p
    );
    exit(EXIT_FAILURE);
}


static void
verify_success(int status, const char *message_p) {
    if (status == -1) {
	perror(message_p);
	exit(EXIT_FAILURE);
    }
}


static int
isstdindata(int timeout) {
    struct pollfd	in = {0, POLLIN | POLLERR | POLLPRI, 0};
    int			num_fds;

    while (((num_fds = poll(&in, 1, timeout)) == -1) && (errno == EINTR))
	;

    return ((num_fds == 1) && (in.revents & (POLLIN | POLLPRI)));
}


#define ADCHANNEL7	DM6430HR_AIN1		// A/D channel
#define RATE7		50			// Clock rate in 'Hz'
#define IRQCHANNEL7	DM6430HR_INT1		// interrupt channel
#define ADSLOPE7	(65536.0/20.0)		// Number Bits divided by AD Range


int
main(int argument_count, char **arguments_p_p) {
    double		ActualRate0;
    double		dummy;
    int			descriptor;
    int			status;
    unsigned int	minor_number;
    unsigned long	count = 0;

    program_name_p = arguments_p_p[0];

    if (argument_count != 2) {
	fprintf(stderr, "Invalid number of options given.\n");
	usage();
    }

    if (sscanf(arguments_p_p[1], "%u", &minor_number) == 0) {
	fprintf(stderr, "Invalid device minor number.\n");
	usage();
    }

    descriptor = OpenBoard6430(minor_number);
    verify_success(descriptor, "OpenBoard6430() FAILED");

    status = InitBoard6430(descriptor);
    verify_success(status, "InitBoard6430() FAILED");

    status = DIOSetPort0Direction6430(descriptor, 0);
    verify_success(status, "DIOSetPort0Direction6430() FAILED");

    status = SetUserClock6430(
	descriptor, DM6430HR_CLK0, 8000000, 20000, &ActualRate0
    );
    verify_success(status, "SetUserClock6430() FAILED");

    status = SetUserClock6430(
	descriptor, DM6430HR_CLK1, ActualRate0, RATE7, &dummy
    );
    verify_success(status, "SetUserClock6430() FAILED");

    status = SetConversionSelect6430(descriptor, DM6430HR_CONV_SOFT_TRIGGER);
    verify_success(status, "SetConversionSelect6430() FAILED");

    status = SetChannelGain6430(
	descriptor,
	ADCHANNEL7,
	DM6430HR_GAINx1,
	DM6430HR_SE_SE
    );
    verify_success(status, "SetChannelGain6430() FAILED");

    status = SetIRQ0Source6430(descriptor, IRQS_TC_COUNTER1_6430);
    verify_success(status, "SetIRQ0Source6430() FAILED");

    fprintf(
	stdout,
	"IRQ has been set up.\nInput channel AIN%d sampled at %d Hz.\n",
	ADCHANNEL7 + 1,
	RATE7
    );

    status = ClearIRQ06430(descriptor);
    verify_success(status, "ClearIRQ06430() FAILED");

    status = EnableIRQ6430(descriptor, IRQCHANNEL7);
    verify_success(status, "EnableIRQ6430() FAILED");

    while (!isstdindata(100)) {
	unsigned long	irq_counter;

	status = GetIRQCounter6430(descriptor, IRQCHANNEL7, &irq_counter);
	verify_success(status, "GetIRQCounter6430() FAILED");

	if (count != irq_counter) {
	    int		empty_flag;
	    int16_t	data;

	    count = irq_counter;
	    status = ClearADFIFO6430(descriptor);
	    verify_success(status, "ClearADFIFO6430() FAILED");

	    status = StartConversion6430(descriptor);
	    verify_success(status, "StartConversion6430() FAILED");

	    do {
		status = IsADFIFOEmpty6430(descriptor, &empty_flag);
		verify_success(status, "IsADFIFOEmpty6430() FAILED");
	    } while (empty_flag);

	    status = ReadADData6430(descriptor, &data);
	    verify_success(status, "ReadADData6430() FAILED");
	    fprintf(stdout, "%+5.2lf mV\n", data / ADSLOPE7);
	}
    }

    status = DisableIRQ6430(descriptor, IRQCHANNEL7);
    verify_success(status, "DisableIRQ6430() FAILED");

    status = DoneTimer6430(descriptor);
    verify_success(status, "DoneTimer6430() FAILED");

    exit(EXIT_SUCCESS);
}