annotate projects/basic_analog_output/main.cpp @ 39:638bc1ae2500 staging

Improved readibility of the DIGITAL code in the PRU, using register names instead of aliases and expanding some of the macros, removing unused macros. Binaries were not modified

/*
 * main.cpp
 *
 *  Created on: Oct 24, 2014
 *      Author: parallels
 */

#include <iostream>
#include <cstdlib>
#include <libgen.h>
#include <signal.h>
#include <getopt.h>
#include "../../include/RTAudio.h"

using namespace std;

// Handle Ctrl-C by requesting that the audio rendering stop
void interrupt_handler(int var)
{
	gShouldStop = true;
}

// Print usage information
void usage(const char * processName)
{
	cerr << "Usage: " << processName << " [options]" << endl;

	BeagleRT_usage();

	cerr << "   --frequency [-f] frequency: Set the frequency of the LED fade (default: 1.0)\n";
	cerr << "   --help [-h]:                Print this menu\n";
}

int main(int argc, char *argv[])
{
	RTAudioSettings settings;	// Standard audio settings
	float frequency = 1.0;	// Frequency of LED fades

	struct option customOptions[] =
	{
		{"help", 0, NULL, 'h'},
		{"frequency", 1, NULL, 'f'},
		{NULL, 0, NULL, 0}
	};

	// Set default settings
	BeagleRT_defaultSettings(&settings);

	// In this example, audio isn't used so might as well leave speaker muted
	settings.beginMuted = 1;

	// Parse command-line arguments
	while (1) {
		int c;
		if ((c = BeagleRT_getopt_long(argc, argv, "hf:", customOptions, &settings)) < 0)
				break;
		switch (c) {
		case 'h':
				usage(basename(argv[0]));
				exit(0);
		case 'f':
				frequency = atof(optarg);
				if(frequency < 0)
					frequency = 0;
				if(frequency > 11025.0)
					frequency = 11025.0;
				break;
		case '?':
		default:
				usage(basename(argv[0]));
				exit(1);
		}
	}

	// Initialise the PRU audio device
	if(BeagleRT_initAudio(&settings, &frequency) != 0) {
		cout << "Error: unable to initialise audio" << endl;
		return -1;
	}

	// Start the audio device running
	if(BeagleRT_startAudio()) {
		cout << "Error: unable to start real-time audio" << endl;
		return -1;
	}

	// Set up interrupt handler to catch Control-C and SIGTERM
	signal(SIGINT, interrupt_handler);
	signal(SIGTERM, interrupt_handler);

	// Run until told to stop
	while(!gShouldStop) {
		usleep(100000);
	}

	// Stop the audio device
	BeagleRT_stopAudio();

	// Clean up any resources allocated for audio
	BeagleRT_cleanupAudio();

	// All done!
	return 0;
}