Package lejos.hardware

Class Sound

java.lang.Object

lejos.hardware.Sound

All Implemented Interfaces:

Sounds

public class Sound
extends java.lang.Object
implements Sounds

Class that provides access methods for the local audio device

Field Summary

Fields

Modifier and Type	Field	Description
protected static Audio	audio
static int	C2
static java.lang.String	VOL_SETTING

Fields inherited from interface lejos.hardware.Sounds

ASCENDING, BEEP, BUZZ, DESCENDING, DOUBLE_BEEP, FLUTE, PIANO, VOL_MAX, XYLOPHONE

Method Summary

Modifier and Type	Method	Description
static void	beep()	Beeps once.
static void	beepSequence()	Downward tones.
static void	beepSequenceUp()	Upward tones.
static void	buzz()	Low buzz
static int	getTime()	Returns the number of milliseconds remaining of the current tone or sample.
static int	getVolume()	Get the current master volume level
static void	loadSettings()	Load the current system settings associated with this class.
static void	pause(int t)
static void	playNote(int[] inst, int freq, int len)	Play a note with attack, decay, sustain and release shape, which is known as a ADSR envelope.
static int	playSample(byte[] data, int offset, int len, int freq, int vol)	Queue a series of PCM samples to play at the specified volume and sample rate.
static int	playSample(java.io.File file)	Play a wav file.
static int	playSample(java.io.File file, int vol)	Play a wav file.
static void	playTone(int freq, int duration)	Plays a tone, given its frequency and duration.
static void	playTone(int aFrequency, int aDuration, int aVolume)	Plays a tone, given its frequency and duration.
static void	setVolume(int vol)	Set the master volume level
static void	systemSound(boolean aQueued, int aCode)	Play a system sound.
static void	twoBeeps()	Beeps twice.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

audio

protected static final Audio audio

VOL_SETTING

public static final java.lang.String VOL_SETTING

See Also:

Constant Field Values

C2

public static int C2

Method Detail

systemSound

public static void systemSound(boolean aQueued,
                               int aCode)

Play a system sound.

aCode	Resulting Sound
0	short beep
1	double beep
2	descending arpeggio
3	ascending arpeggio
4	long, low buzz

beep

public static void beep()

Beeps once.

twoBeeps

public static void twoBeeps()

Beeps twice.

beepSequence

public static void beepSequence()

Downward tones.

beepSequenceUp

public static void beepSequenceUp()

Upward tones.

buzz

public static void buzz()

Low buzz

pause

public static void pause(int t)

getTime

public static int getTime()

Returns the number of milliseconds remaining of the current tone or sample.

Returns:

milliseconds remaining

playTone

public static void playTone(int aFrequency,
                            int aDuration,
                            int aVolume)

Plays a tone, given its frequency and duration.

Parameters:

aFrequency - The frequency of the tone in Hertz (Hz).

aDuration - The duration of the tone, in milliseconds.

aVolume - The volume of the playback 100 corresponds to 100%

playTone

public static void playTone(int freq,
                            int duration)

Plays a tone, given its frequency and duration.

Parameters:

freq - The frequency of the tone in Hertz (Hz).

duration - The duration of the tone, in milliseconds.

playSample

public static int playSample(java.io.File file,
                             int vol)

Play a wav file. Must be mono, from 8kHz to 48kHz, and 8-bit or 16-bit.

Parameters:

file - the 8-bit or 16-bit PWM (WAV) sample file

vol - the volume percentage 0 - 100

Returns:

The number of milliseconds the sample will play for or < 0 if there is an error.

Throws:

java.io.FileNotFoundException

playSample

public static int playSample(java.io.File file)

Play a wav file. Must be mono, from 8kHz to 48kHz, and 8-bit or 16-bit.

Parameters:

file - the 8-bit or 16-bit PWM (WAV) sample file

Returns:

The number of milliseconds the sample will play for or < 0 if there is an error.

Throws:

java.io.FileNotFoundException

playSample

public static int playSample(byte[] data,
                             int offset,
                             int len,
                             int freq,
                             int vol)

Queue a series of PCM samples to play at the specified volume and sample rate.

Parameters:

data - Buffer containing the samples

offset - Offset of the first sample in the buffer

len - Number of samples to queue

freq - Sample rate

vol - playback volume

Returns:

Number of samples actually queued

playNote

public static void playNote(int[] inst,
                            int freq,
                            int len)

Play a note with attack, decay, sustain and release shape, which is known as a ADSR envelope. This function plays a more musical sounding note compared to playTone(). It uses a set of supplied "instrument" parameters to define the shape of the note's envelope.

Instruments are defined in the Sounds interface, which is inherited by this class. For example, the piano instrument array looks like this:

public final static int[] PIANO = new int[]{4, 25, 500, 7000, 5};

The parameter len is the total time of the note to be played val 0 is the attack time the time for the volume to go from near zero to 100% val 1 is the decay time during this period the volume decreases by val[2]/100 to the sustain level. the sustain period is (len - val[0] - val[1] - val[4]) during this period the volume decreases by val[3]/100. the final decay period is val[4] and the volume reduces to zero. All of the times are units of 2mS (except for len which is in mS).

Because values equal 2ms, the piano array numbers are doubled:
1. take 8mS to increase the volume from zero to 100%
2. take 50mS to decrese the volume by 5%
3. take len - 8 - 25 - 10 mS to decrease the volume by 70%
4. take 10mS to decrease the volume to 0

Parameters:

inst - Instrument definition (5 ints in an array).

freq - The note to play (in Hz)

len - The duration of the note (in ms)

setVolume

public static void setVolume(int vol)

Set the master volume level

Parameters:

vol - 0-100

getVolume

public static int getVolume()

Get the current master volume level

Returns:

the current master volume 0-100

loadSettings

public static void loadSettings()

Load the current system settings associated with this class. Called automatically to initialize the class. May be called if it is required to reload any settings.