blink.c

/*
 * Copyright (c) 2015,
 * National Instruments Corporation.
 * All rights reserved.
 */

#include <stdio.h>
#include <time.h>
#include "MyRio.h"

#define delay 1 // how long, in seconds, to blink to LED
#define ledBit 0 // LED number to blink

// global session variable, defined in myRIO.c
extern NiFpga_Session myrio_session;


// blinks LED0 off and on
int main(int argc, char **argv)
{
	printf("LED Blink\n");
    NiFpga_Status status;

    /*
     * Open the myRIO NiFpga Session.
     * This function MUST be called before all other functions. After this call
     * is complete the myRIO target will be ready to be used.
     */
    status = MyRio_Open();
    if (MyRio_IsNotSuccess(status))
    {
    	printf("Failed to initialize NiFpga session\n");
        return status;
    }

    // read in current LED register bank value
    uint8_t ledValue;
    NiFpga_MergeStatus(&status,
                NiFpga_ReadU8(myrio_session, DOLED30, &ledValue));

    if (MyRio_IsNotSuccess(status)) {
    	printf("Failed to read from LED register\n");
    	return status;
    }

    // begin blink loop
    time_t currentTime;
    time_t finalTime;
    uint8_t ledState = 1;
    while (1) {
    	// set LED to current value
    	if (ledState == 1) {
    		printf("Turning LED on\n");
    		ledValue = ledValue | (1 << ledBit);
    	} else {
    		printf("Turning LED off\n");
    		ledValue = ledValue & ~(1 << ledBit);
    	}

    	// write register value
    	NiFpga_MergeStatus(&status,
    	            NiFpga_WriteU8(myrio_session, DOLED30, ledValue));

    	if (MyRio_IsNotSuccess(status)) {
    		printf("Failed to write to LED register\n");
    		return status;
    	}

    	ledState = ~ledState;
    	// delay
    	time(&currentTime);
    	finalTime = currentTime + delay;
    	while (currentTime < finalTime) time(&currentTime);
    }
}