annotate projects/basic_analog_output/main.cpp @ 45:579c86316008 newapi

Major API overhaul. Moved to a single data structure for handling render functions. Functionally, generally similar except for scheduling within PRU loop function, which now uses interrupts from the PRU rather than polling. This requires an updated kernel.

/*
 * 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;
}