dm6430-sample-counter.c

rt 6430 采集卡 linux下驱动源代码

/*
	FILE NAME: dm6430-sample-counter.c

	FILE DESCRIPTION: Sample counter example program

		This program demonstrates how to use the sample counter to
		generate interrupts.

		The pacer clock is used to drive A/D conversion.  Conversion
		is started by a software trigger.  Conversion is stopped when
		the sample counter counts down.  Samples are 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 ADCHANNEL9	DM6430HR_AIN1	// A/D channel
#define RATE9		1000		// Clock rate in 'Hz'
#define ADSLOPE9	(65536.0/20.0)	// Number Bits divided by AD Range
#define NUM_OF_SAMPLES9	512		// Number of samples in a buffer
#define IRQCHANNEL9	DM6430HR_INT1	// interrupt channel


int
main(int argument_count, char **arguments_p_p) {
    double		Actual_PACER_RATE;
    int			descriptor;
    int			monSamples1 = 200;
    int			status;
    unsigned int	minor_number;
    unsigned long	local_counter = 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 = SetPacerClock6430(descriptor, RATE9, &Actual_PACER_RATE);
    verify_success(status, "SetPacerClock6430() FAILED");

    status = SetStartTrigger6430(descriptor, DM6430HR_START_TRIG_SOFTWARE);
    verify_success(status, "SetStartTrigger6430() FAILED");

    status = SetStopTrigger6430(descriptor, DM6430HR_STOP_TRIG_SAMPLE_CNT);
    verify_success(status, "SetStopTrigger6430() FAILED");

    status = SetConversionSelect6430(descriptor, DM6430HR_CONV_PACER_CLOCK);
    verify_success(status, "SetConversionSelect6430() FAILED");

    status = SetChannelGain6430(
	descriptor,
	ADCHANNEL9,
	DM6430HR_GAINx1,
	DM6430HR_SE_SE
    );
    verify_success(status, "SetChannelGain6430() FAILED");

    status = LoadADSampleCounter6430(descriptor, NUM_OF_SAMPLES9);
    verify_success(status, "LoadADSampleCounter6430() FAILED");

    status = SetIRQ0Source6430(descriptor, IRQS_AD_SAMPLE_CNT_6430);
    verify_success(status, "SetIRQ0Source6430() FAILED");

    fprintf(stdout, "Channel AIN%d : %6.2lf Volts\n", ADCHANNEL9 + 1, 0.0);
    fprintf(
	stdout,
	"IRQ has been set up.\nInput channel AIN%d sampled at %d Hz.\n",
	ADCHANNEL9 + 1,
	RATE9
    );
    
    status = ClearIRQ06430(descriptor);
    verify_success(status, "ClearIRQ06430() FAILED");

    status = EnableIRQ6430(descriptor, IRQCHANNEL9);
    verify_success(status, "EnableIRQ6430() FAILED");

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

    while (!isstdindata(200)) { 
	unsigned long	irqcounter;
	
	status = GetIRQCounter6430(descriptor, IRQCHANNEL9, &irqcounter);
	verify_success(status, "GetIRQCounter6430() FAILED");

	/*
	 * The code in the following if-statement is executed exactly once
	 * since only one interrupt should occur and then A/D conversion is
	 * halted.
	 */

	if (irqcounter != local_counter) {
	    int		sample;
	    int16_t	data;

	    local_counter = irqcounter;

	    for (sample = 0; sample < monSamples1; sample++) {
		status = ReadADData6430(descriptor, &data);
		verify_success(status, "ReadADData6430() FAILED");
		fprintf(stdout, "%5.2lf mV\n", data / ADSLOPE9);
	    }

	    fprintf(stdout, "# of interrupts: %ld\n", irqcounter);
	    fprintf(stdout, "Conversion halted.  Press ENTER to exit.\n");
	}
    }

    status = DisableIRQ6430(descriptor, IRQCHANNEL9);
    verify_success(status, "DisableIRQ6430() FAILED");

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

    status = CloseBoard6430(descriptor);
    verify_success(status, "CloseBoard6430() FAILED");

    exit(EXIT_SUCCESS);
}