' ********************************************************************
'
'  $Id: svn_id $
'
'  Implements yFindBuzzer(), the high-level API for Buzzer functions
'
'  - - - - - - - - - License information: - - - - - - - - -
'
'  Copyright (C) 2011 and beyond by Yoctopuce Sarl, Switzerland.
'
'  Yoctopuce Sarl (hereafter Licensor) grants to you a perpetual
'  non-exclusive license to use, modify, copy and integrate this
'  file into your software for the sole purpose of interfacing
'  with Yoctopuce products.
'
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'  source or object form, as long as the sole purpose of this
'  code is to interface with Yoctopuce products. You must retain
'  this notice in the distributed source file.
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'  THE SOFTWARE AND DOCUMENTATION ARE PROVIDED 'AS IS' WITHOUT
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' *********************************************************************


Imports YDEV_DESCR = System.Int32
Imports YFUN_DESCR = System.Int32
Imports System.Runtime.InteropServices
Imports System.Text

Module yocto_buzzer

    REM --- (YBuzzer return codes)
    REM --- (end of YBuzzer return codes)
    REM --- (YBuzzer dlldef)
    REM --- (end of YBuzzer dlldef)
   REM --- (YBuzzer yapiwrapper)
   REM --- (end of YBuzzer yapiwrapper)
  REM --- (YBuzzer globals)

  Public Const Y_FREQUENCY_INVALID As Double = YAPI.INVALID_DOUBLE
  Public Const Y_VOLUME_INVALID As Integer = YAPI.INVALID_UINT
  Public Const Y_PLAYSEQSIZE_INVALID As Integer = YAPI.INVALID_UINT
  Public Const Y_PLAYSEQMAXSIZE_INVALID As Integer = YAPI.INVALID_UINT
  Public Const Y_PLAYSEQSIGNATURE_INVALID As Integer = YAPI.INVALID_UINT
  Public Const Y_COMMAND_INVALID As String = YAPI.INVALID_STRING
  Public Delegate Sub YBuzzerValueCallback(ByVal func As YBuzzer, ByVal value As String)
  Public Delegate Sub YBuzzerTimedReportCallback(ByVal func As YBuzzer, ByVal measure As YMeasure)
  REM --- (end of YBuzzer globals)

  REM --- (YBuzzer class start)

  '''*
  ''' <summary>
  '''   The <c>YBuzzer</c> class allows you to drive a buzzer.
  ''' <para>
  '''   You can
  '''   choose the frequency and the volume at which the buzzer must sound.
  '''   You can also pre-program a play sequence.
  ''' </para>
  ''' </summary>
  '''/
  Public Class YBuzzer
    Inherits YFunction
    REM --- (end of YBuzzer class start)

    REM --- (YBuzzer definitions)
    Public Const FREQUENCY_INVALID As Double = YAPI.INVALID_DOUBLE
    Public Const VOLUME_INVALID As Integer = YAPI.INVALID_UINT
    Public Const PLAYSEQSIZE_INVALID As Integer = YAPI.INVALID_UINT
    Public Const PLAYSEQMAXSIZE_INVALID As Integer = YAPI.INVALID_UINT
    Public Const PLAYSEQSIGNATURE_INVALID As Integer = YAPI.INVALID_UINT
    Public Const COMMAND_INVALID As String = YAPI.INVALID_STRING
    REM --- (end of YBuzzer definitions)

    REM --- (YBuzzer attributes declaration)
    Protected _frequency As Double
    Protected _volume As Integer
    Protected _playSeqSize As Integer
    Protected _playSeqMaxSize As Integer
    Protected _playSeqSignature As Integer
    Protected _command As String
    Protected _valueCallbackBuzzer As YBuzzerValueCallback
    REM --- (end of YBuzzer attributes declaration)

    Public Sub New(ByVal func As String)
      MyBase.New(func)
      _classname = "Buzzer"
      REM --- (YBuzzer attributes initialization)
      _frequency = FREQUENCY_INVALID
      _volume = VOLUME_INVALID
      _playSeqSize = PLAYSEQSIZE_INVALID
      _playSeqMaxSize = PLAYSEQMAXSIZE_INVALID
      _playSeqSignature = PLAYSEQSIGNATURE_INVALID
      _command = COMMAND_INVALID
      _valueCallbackBuzzer = Nothing
      REM --- (end of YBuzzer attributes initialization)
    End Sub

    REM --- (YBuzzer private methods declaration)

    Protected Overrides Function _parseAttr(ByRef json_val As YJSONObject) As Integer
      If json_val.has("frequency") Then
        _frequency = Math.Round(json_val.getDouble("frequency") / 65.536) / 1000.0
      End If
      If json_val.has("volume") Then
        _volume = CInt(json_val.getLong("volume"))
      End If
      If json_val.has("playSeqSize") Then
        _playSeqSize = CInt(json_val.getLong("playSeqSize"))
      End If
      If json_val.has("playSeqMaxSize") Then
        _playSeqMaxSize = CInt(json_val.getLong("playSeqMaxSize"))
      End If
      If json_val.has("playSeqSignature") Then
        _playSeqSignature = CInt(json_val.getLong("playSeqSignature"))
      End If
      If json_val.has("command") Then
        _command = json_val.getString("command")
      End If
      Return MyBase._parseAttr(json_val)
    End Function

    REM --- (end of YBuzzer private methods declaration)

    REM --- (YBuzzer public methods declaration)

    '''*
    ''' <summary>
    '''   Changes the frequency of the signal sent to the buzzer.
    ''' <para>
    '''   A zero value stops the buzzer.
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="newval">
    '''   a floating point number corresponding to the frequency of the signal sent to the buzzer
    ''' </param>
    ''' <para>
    ''' </para>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns a negative error code.
    ''' </para>
    '''/
    Public Function set_frequency(ByVal newval As Double) As Integer
      Dim rest_val As String
      rest_val = Ltrim(Str(Math.Round(newval * 65536.0)))
      Return _setAttr("frequency", rest_val)
    End Function
    '''*
    ''' <summary>
    '''   Returns the  frequency of the signal sent to the buzzer/speaker.
    ''' <para>
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   a floating point number corresponding to the  frequency of the signal sent to the buzzer/speaker
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns <c>YBuzzer.FREQUENCY_INVALID</c>.
    ''' </para>
    '''/
    Public Function get_frequency() As Double
      Dim res As Double = 0
      If (Me._cacheExpiration <= YAPI.GetTickCount()) Then
        If (Me.load(YAPI._yapiContext.GetCacheValidity()) <> YAPI.SUCCESS) Then
          Return FREQUENCY_INVALID
        End If
      End If
      res = Me._frequency
      Return res
    End Function

    '''*
    ''' <summary>
    '''   Returns the volume of the signal sent to the buzzer/speaker.
    ''' <para>
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   an integer corresponding to the volume of the signal sent to the buzzer/speaker
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns <c>YBuzzer.VOLUME_INVALID</c>.
    ''' </para>
    '''/
    Public Function get_volume() As Integer
      Dim res As Integer = 0
      If (Me._cacheExpiration <= YAPI.GetTickCount()) Then
        If (Me.load(YAPI._yapiContext.GetCacheValidity()) <> YAPI.SUCCESS) Then
          Return VOLUME_INVALID
        End If
      End If
      res = Me._volume
      Return res
    End Function


    '''*
    ''' <summary>
    '''   Changes the volume of the signal sent to the buzzer/speaker.
    ''' <para>
    '''   Remember to call the
    '''   <c>saveToFlash()</c> method of the module if the modification must be kept.
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="newval">
    '''   an integer corresponding to the volume of the signal sent to the buzzer/speaker
    ''' </param>
    ''' <para>
    ''' </para>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns a negative error code.
    ''' </para>
    '''/
    Public Function set_volume(ByVal newval As Integer) As Integer
      Dim rest_val As String
      rest_val = Ltrim(Str(newval))
      Return _setAttr("volume", rest_val)
    End Function
    '''*
    ''' <summary>
    '''   Returns the current length of the playing sequence.
    ''' <para>
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   an integer corresponding to the current length of the playing sequence
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns <c>YBuzzer.PLAYSEQSIZE_INVALID</c>.
    ''' </para>
    '''/
    Public Function get_playSeqSize() As Integer
      Dim res As Integer = 0
      If (Me._cacheExpiration <= YAPI.GetTickCount()) Then
        If (Me.load(YAPI._yapiContext.GetCacheValidity()) <> YAPI.SUCCESS) Then
          Return PLAYSEQSIZE_INVALID
        End If
      End If
      res = Me._playSeqSize
      Return res
    End Function

    '''*
    ''' <summary>
    '''   Returns the maximum length of the playing sequence.
    ''' <para>
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   an integer corresponding to the maximum length of the playing sequence
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns <c>YBuzzer.PLAYSEQMAXSIZE_INVALID</c>.
    ''' </para>
    '''/
    Public Function get_playSeqMaxSize() As Integer
      Dim res As Integer = 0
      If (Me._cacheExpiration = 0) Then
        If (Me.load(YAPI._yapiContext.GetCacheValidity()) <> YAPI.SUCCESS) Then
          Return PLAYSEQMAXSIZE_INVALID
        End If
      End If
      res = Me._playSeqMaxSize
      Return res
    End Function

    '''*
    ''' <summary>
    '''   Returns the playing sequence signature.
    ''' <para>
    '''   As playing
    '''   sequences cannot be read from the device, this can be used
    '''   to detect if a specific playing sequence is already
    '''   programmed.
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   an integer corresponding to the playing sequence signature
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns <c>YBuzzer.PLAYSEQSIGNATURE_INVALID</c>.
    ''' </para>
    '''/
    Public Function get_playSeqSignature() As Integer
      Dim res As Integer = 0
      If (Me._cacheExpiration <= YAPI.GetTickCount()) Then
        If (Me.load(YAPI._yapiContext.GetCacheValidity()) <> YAPI.SUCCESS) Then
          Return PLAYSEQSIGNATURE_INVALID
        End If
      End If
      res = Me._playSeqSignature
      Return res
    End Function

    Public Function get_command() As String
      Dim res As String
      If (Me._cacheExpiration <= YAPI.GetTickCount()) Then
        If (Me.load(YAPI._yapiContext.GetCacheValidity()) <> YAPI.SUCCESS) Then
          Return COMMAND_INVALID
        End If
      End If
      res = Me._command
      Return res
    End Function


    Public Function set_command(ByVal newval As String) As Integer
      Dim rest_val As String
      rest_val = newval
      Return _setAttr("command", rest_val)
    End Function
    '''*
    ''' <summary>
    '''   Retrieves a buzzer for a given identifier.
    ''' <para>
    '''   The identifier can be specified using several formats:
    ''' </para>
    ''' <para>
    ''' </para>
    ''' <para>
    '''   - FunctionLogicalName
    ''' </para>
    ''' <para>
    '''   - ModuleSerialNumber.FunctionIdentifier
    ''' </para>
    ''' <para>
    '''   - ModuleSerialNumber.FunctionLogicalName
    ''' </para>
    ''' <para>
    '''   - ModuleLogicalName.FunctionIdentifier
    ''' </para>
    ''' <para>
    '''   - ModuleLogicalName.FunctionLogicalName
    ''' </para>
    ''' <para>
    ''' </para>
    ''' <para>
    '''   This function does not require that the buzzer is online at the time
    '''   it is invoked. The returned object is nevertheless valid.
    '''   Use the method <c>YBuzzer.isOnline()</c> to test if the buzzer is
    '''   indeed online at a given time. In case of ambiguity when looking for
    '''   a buzzer by logical name, no error is notified: the first instance
    '''   found is returned. The search is performed first by hardware name,
    '''   then by logical name.
    ''' </para>
    ''' <para>
    '''   If a call to this object's is_online() method returns FALSE although
    '''   you are certain that the matching device is plugged, make sure that you did
    '''   call registerHub() at application initialization time.
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="func">
    '''   a string that uniquely characterizes the buzzer, for instance
    '''   <c>YBUZZER2.buzzer</c>.
    ''' </param>
    ''' <returns>
    '''   a <c>YBuzzer</c> object allowing you to drive the buzzer.
    ''' </returns>
    '''/
    Public Shared Function FindBuzzer(func As String) As YBuzzer
      Dim obj As YBuzzer
      obj = CType(YFunction._FindFromCache("Buzzer", func), YBuzzer)
      If ((obj Is Nothing)) Then
        obj = New YBuzzer(func)
        YFunction._AddToCache("Buzzer", func, obj)
      End If
      Return obj
    End Function

    '''*
    ''' <summary>
    '''   Registers the callback function that is invoked on every change of advertised value.
    ''' <para>
    '''   The callback is then invoked only during the execution of <c>ySleep</c> or <c>yHandleEvents</c>.
    '''   This provides control over the time when the callback is triggered. For good responsiveness,
    '''   remember to call one of these two functions periodically. The callback is called once juste after beeing
    '''   registered, passing the current advertised value  of the function, provided that it is not an empty string.
    '''   To unregister a callback, pass a Nothing pointer as argument.
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="callback">
    '''   the callback function to call, or a Nothing pointer. The callback function should take two
    '''   arguments: the function object of which the value has changed, and the character string describing
    '''   the new advertised value.
    ''' @noreturn
    ''' </param>
    '''/
    Public Overloads Function registerValueCallback(callback As YBuzzerValueCallback) As Integer
      Dim val As String
      If (Not (callback Is Nothing)) Then
        YFunction._UpdateValueCallbackList(Me, True)
      Else
        YFunction._UpdateValueCallbackList(Me, False)
      End If
      Me._valueCallbackBuzzer = callback
      REM // Immediately invoke value callback with current value
      If (Not (callback Is Nothing) AndAlso Me.isOnline()) Then
        val = Me._advertisedValue
        If (Not (val = "")) Then
          Me._invokeValueCallback(val)
        End If
      End If
      Return 0
    End Function

    Public Overrides Function _invokeValueCallback(value As String) As Integer
      If (Not (Me._valueCallbackBuzzer Is Nothing)) Then
        Me._valueCallbackBuzzer(Me, value)
      Else
        MyBase._invokeValueCallback(value)
      End If
      Return 0
    End Function

    Public Overridable Function sendCommand(command As String) As Integer
      Return Me.set_command(command)
    End Function

    '''*
    ''' <summary>
    '''   Adds a new frequency transition to the playing sequence.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="freq">
    '''   desired frequency when the transition is completed, in Hz
    ''' </param>
    ''' <param name="msDelay">
    '''   duration of the frequency transition, in milliseconds.
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function addFreqMoveToPlaySeq(freq As Integer, msDelay As Integer) As Integer
      Return Me.sendCommand("A" + Convert.ToString(freq) + "," + Convert.ToString(msDelay))
    End Function

    '''*
    ''' <summary>
    '''   Adds a pulse to the playing sequence.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="freq">
    '''   pulse frequency, in Hz
    ''' </param>
    ''' <param name="msDuration">
    '''   pulse duration, in milliseconds.
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function addPulseToPlaySeq(freq As Integer, msDuration As Integer) As Integer
      Return Me.sendCommand("B" + Convert.ToString(freq) + "," + Convert.ToString(msDuration))
    End Function

    '''*
    ''' <summary>
    '''   Adds a new volume transition to the playing sequence.
    ''' <para>
    '''   Frequency stays untouched:
    '''   if frequency is at zero, the transition has no effect.
    ''' </para>
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="volume">
    '''   desired volume when the transition is completed, as a percentage.
    ''' </param>
    ''' <param name="msDuration">
    '''   duration of the volume transition, in milliseconds.
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function addVolMoveToPlaySeq(volume As Integer, msDuration As Integer) As Integer
      Return Me.sendCommand("C" + Convert.ToString(volume) + "," + Convert.ToString(msDuration))
    End Function

    '''*
    ''' <summary>
    '''   Adds notes to the playing sequence.
    ''' <para>
    '''   Notes are provided as text words, separated by
    '''   spaces. The pitch is specified using the usual letter from A to G. The duration is
    '''   specified as the divisor of a whole note: 4 for a fourth, 8 for an eight note, etc.
    '''   Some modifiers are supported: <c>#</c> and <c>b</c> to alter a note pitch,
    '''   <c>'</c> and <c>,</c> to move to the upper/lower octave, <c>.</c> to enlarge
    '''   the note duration.
    ''' </para>
    ''' </summary>
    ''' <param name="notes">
    '''   notes to be played, as a text string.
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function addNotesToPlaySeq(notes As String) As Integer
      Dim tempo As Integer = 0
      Dim prevPitch As Integer = 0
      Dim prevDuration As Integer = 0
      Dim prevFreq As Integer = 0
      Dim note As Integer = 0
      Dim num As Integer = 0
      Dim typ As Integer = 0
      Dim ascNotes As Byte() = New Byte(){}
      Dim notesLen As Integer = 0
      Dim i As Integer = 0
      Dim ch As Integer = 0
      Dim dNote As Integer = 0
      Dim pitch As Integer = 0
      Dim freq As Integer = 0
      Dim ms As Integer = 0
      Dim ms16 As Integer = 0
      Dim rest As Integer = 0
      tempo = 100
      prevPitch = 3
      prevDuration = 4
      prevFreq = 110
      note = -99
      num = 0
      typ = 3
      ascNotes = YAPI.DefaultEncoding.GetBytes(notes)
      notesLen = (ascNotes).Length
      i = 0
      While (i < notesLen)
        ch = ascNotes(i)
        REM // A (note))
        If (ch = 65) Then
          note = 0
        End If
        REM // B (note)
        If (ch = 66) Then
          note = 2
        End If
        REM // C (note)
        If (ch = 67) Then
          note = 3
        End If
        REM // D (note)
        If (ch = 68) Then
          note = 5
        End If
        REM // E (note)
        If (ch = 69) Then
          note = 7
        End If
        REM // F (note)
        If (ch = 70) Then
          note = 8
        End If
        REM // G (note)
        If (ch = 71) Then
          note = 10
        End If
        REM // '#' (sharp modifier)
        If (ch = 35) Then
          note = note + 1
        End If
        REM // 'b' (flat modifier)
        If (ch = 98) Then
          note = note - 1
        End If
        REM // ' (octave up)
        If (ch = 39) Then
          prevPitch = prevPitch + 12
        End If
        REM // , (octave down)
        If (ch = 44) Then
          prevPitch = prevPitch - 12
        End If
        REM // R (rest)
        If (ch = 82) Then
          typ = 0
        End If
        REM // ! (staccato modifier)
        If (ch = 33) Then
          typ = 1
        End If
        REM // ^ (short modifier)
        If (ch = 94) Then
          typ = 2
        End If
        REM // _ (legato modifier)
        If (ch = 95) Then
          typ = 4
        End If
        REM // - (glissando modifier)
        If (ch = 45) Then
          typ = 5
        End If
        REM // % (tempo change)
        If ((ch = 37) AndAlso (num > 0)) Then
          tempo = num
          num = 0
        End If
        If ((ch >= 48) AndAlso (ch <= 57)) Then
          REM // 0-9 (number)
          num = (num * 10) + (ch - 48)
        End If
        If (ch = 46) Then
          REM // . (duration modifier)
          num = ((num * 2) \ 3)
        End If
        If (((ch = 32) OrElse (i+1 = notesLen)) AndAlso ((note > -99) OrElse (typ <> 3))) Then
          If (num = 0) Then
            num = prevDuration
          Else
            prevDuration = num
          End If
          ms = CType(Math.Round(320000.0 / (tempo * num)), Integer)
          If (typ = 0) Then
            Me.addPulseToPlaySeq(0, ms)
          Else
            dNote = note - (((prevPitch) Mod (12)))
            If (dNote > 6) Then
              dNote = dNote - 12
            End If
            If (dNote <= -6) Then
              dNote = dNote + 12
            End If
            pitch = prevPitch + dNote
            freq = CType(Math.Round(440 * Math.exp(pitch * 0.05776226504666)), Integer)
            ms16 = (ms >> 4)
            rest = 0
            If (typ = 3) Then
              rest = 2 * ms16
            End If
            If (typ = 2) Then
              rest = 8 * ms16
            End If
            If (typ = 1) Then
              rest = 12 * ms16
            End If
            If (typ = 5) Then
              Me.addPulseToPlaySeq(prevFreq, ms16)
              Me.addFreqMoveToPlaySeq(freq, 8 * ms16)
              Me.addPulseToPlaySeq(freq, ms - 9 * ms16)
            Else
              Me.addPulseToPlaySeq(freq, ms - rest)
              If (rest > 0) Then
                Me.addPulseToPlaySeq(0, rest)
              End If
            End If
            prevFreq = freq
            prevPitch = pitch
          End If
          note = -99
          num = 0
          typ = 3
        End If
        i = i + 1
      End While
      Return YAPI.SUCCESS
    End Function

    '''*
    ''' <summary>
    '''   Starts the preprogrammed playing sequence.
    ''' <para>
    '''   The sequence
    '''   runs in loop until it is stopped by stopPlaySeq or an explicit
    '''   change. To play the sequence only once, use <c>oncePlaySeq()</c>.
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function startPlaySeq() As Integer
      Return Me.sendCommand("S")
    End Function

    '''*
    ''' <summary>
    '''   Stops the preprogrammed playing sequence and sets the frequency to zero.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function stopPlaySeq() As Integer
      Return Me.sendCommand("X")
    End Function

    '''*
    ''' <summary>
    '''   Resets the preprogrammed playing sequence and sets the frequency to zero.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function resetPlaySeq() As Integer
      Return Me.sendCommand("Z")
    End Function

    '''*
    ''' <summary>
    '''   Starts the preprogrammed playing sequence and run it once only.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function oncePlaySeq() As Integer
      Return Me.sendCommand("s")
    End Function

    '''*
    ''' <summary>
    '''   Saves the preprogrammed playing sequence to flash memory.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function savePlaySeq() As Integer
      Return Me.sendCommand("W")
    End Function

    '''*
    ''' <summary>
    '''   Reloads the preprogrammed playing sequence from the flash memory.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function reloadPlaySeq() As Integer
      Return Me.sendCommand("R")
    End Function

    '''*
    ''' <summary>
    '''   Activates the buzzer for a short duration.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="frequency">
    '''   pulse frequency, in hertz
    ''' </param>
    ''' <param name="duration">
    '''   pulse duration in milliseconds
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns a negative error code.
    ''' </para>
    '''/
    Public Overridable Function pulse(frequency As Integer, duration As Integer) As Integer
      Return Me.set_command("P" + Convert.ToString(frequency) + "," + Convert.ToString(duration))
    End Function

    '''*
    ''' <summary>
    '''   Makes the buzzer frequency change over a period of time.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="frequency">
    '''   frequency to reach, in hertz. A frequency under 25Hz stops the buzzer.
    ''' </param>
    ''' <param name="duration">
    '''   pulse duration in milliseconds
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns a negative error code.
    ''' </para>
    '''/
    Public Overridable Function freqMove(frequency As Integer, duration As Integer) As Integer
      Return Me.set_command("F" + Convert.ToString(frequency) + "," + Convert.ToString(duration))
    End Function

    '''*
    ''' <summary>
    '''   Makes the buzzer volume change over a period of time, frequency  stays untouched.
    ''' <para>
    ''' </para>
    ''' </summary>
    ''' <param name="volume">
    '''   volume to reach in %
    ''' </param>
    ''' <param name="duration">
    '''   change duration in milliseconds
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    ''' </returns>
    ''' <para>
    '''   On failure, throws an exception or returns a negative error code.
    ''' </para>
    '''/
    Public Overridable Function volumeMove(volume As Integer, duration As Integer) As Integer
      Return Me.set_command("V" + Convert.ToString(volume) + "," + Convert.ToString(duration))
    End Function

    '''*
    ''' <summary>
    '''   Immediately play a note sequence.
    ''' <para>
    '''   Notes are provided as text words, separated by
    '''   spaces. The pitch is specified using the usual letter from A to G. The duration is
    '''   specified as the divisor of a whole note: 4 for a fourth, 8 for an eight note, etc.
    '''   Some modifiers are supported: <c>#</c> and <c>b</c> to alter a note pitch,
    '''   <c>'</c> and <c>,</c> to move to the upper/lower octave, <c>.</c> to enlarge
    '''   the note duration.
    ''' </para>
    ''' </summary>
    ''' <param name="notes">
    '''   notes to be played, as a text string.
    ''' </param>
    ''' <returns>
    '''   <c>YAPI.SUCCESS</c> if the call succeeds.
    '''   On failure, throws an exception or returns a negative error code.
    ''' </returns>
    '''/
    Public Overridable Function playNotes(notes As String) As Integer
      Me.resetPlaySeq()
      Me.addNotesToPlaySeq(notes)
      Return Me.oncePlaySeq()
    End Function


    '''*
    ''' <summary>
    '''   Continues the enumeration of buzzers started using <c>yFirstBuzzer()</c>.
    ''' <para>
    '''   Caution: You can't make any assumption about the returned buzzers order.
    '''   If you want to find a specific a buzzer, use <c>Buzzer.findBuzzer()</c>
    '''   and a hardwareID or a logical name.
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   a pointer to a <c>YBuzzer</c> object, corresponding to
    '''   a buzzer currently online, or a <c>Nothing</c> pointer
    '''   if there are no more buzzers to enumerate.
    ''' </returns>
    '''/
    Public Function nextBuzzer() As YBuzzer
      Dim hwid As String = ""
      If (YISERR(_nextFunction(hwid))) Then
        Return Nothing
      End If
      If (hwid = "") Then
        Return Nothing
      End If
      Return YBuzzer.FindBuzzer(hwid)
    End Function

    '''*
    ''' <summary>
    '''   Starts the enumeration of buzzers currently accessible.
    ''' <para>
    '''   Use the method <c>YBuzzer.nextBuzzer()</c> to iterate on
    '''   next buzzers.
    ''' </para>
    ''' </summary>
    ''' <returns>
    '''   a pointer to a <c>YBuzzer</c> object, corresponding to
    '''   the first buzzer currently online, or a <c>Nothing</c> pointer
    '''   if there are none.
    ''' </returns>
    '''/
    Public Shared Function FirstBuzzer() As YBuzzer
      Dim v_fundescr(1) As YFUN_DESCR
      Dim dev As YDEV_DESCR
      Dim neededsize, err As Integer
      Dim serial, funcId, funcName, funcVal As String
      Dim errmsg As String = ""
      Dim size As Integer = Marshal.SizeOf(v_fundescr(0))
      Dim p As IntPtr = Marshal.AllocHGlobal(Marshal.SizeOf(v_fundescr(0)))

      err = yapiGetFunctionsByClass("Buzzer", 0, p, size, neededsize, errmsg)
      Marshal.Copy(p, v_fundescr, 0, 1)
      Marshal.FreeHGlobal(p)

      If (YISERR(err) Or (neededsize = 0)) Then
        Return Nothing
      End If
      serial = ""
      funcId = ""
      funcName = ""
      funcVal = ""
      errmsg = ""
      If (YISERR(yapiGetFunctionInfo(v_fundescr(0), dev, serial, funcId, funcName, funcVal, errmsg))) Then
        Return Nothing
      End If
      Return YBuzzer.FindBuzzer(serial + "." + funcId)
    End Function

    REM --- (end of YBuzzer public methods declaration)

  End Class

  REM --- (YBuzzer functions)

  '''*
  ''' <summary>
  '''   Retrieves a buzzer for a given identifier.
  ''' <para>
  '''   The identifier can be specified using several formats:
  ''' </para>
  ''' <para>
  ''' </para>
  ''' <para>
  '''   - FunctionLogicalName
  ''' </para>
  ''' <para>
  '''   - ModuleSerialNumber.FunctionIdentifier
  ''' </para>
  ''' <para>
  '''   - ModuleSerialNumber.FunctionLogicalName
  ''' </para>
  ''' <para>
  '''   - ModuleLogicalName.FunctionIdentifier
  ''' </para>
  ''' <para>
  '''   - ModuleLogicalName.FunctionLogicalName
  ''' </para>
  ''' <para>
  ''' </para>
  ''' <para>
  '''   This function does not require that the buzzer is online at the time
  '''   it is invoked. The returned object is nevertheless valid.
  '''   Use the method <c>YBuzzer.isOnline()</c> to test if the buzzer is
  '''   indeed online at a given time. In case of ambiguity when looking for
  '''   a buzzer by logical name, no error is notified: the first instance
  '''   found is returned. The search is performed first by hardware name,
  '''   then by logical name.
  ''' </para>
  ''' <para>
  '''   If a call to this object's is_online() method returns FALSE although
  '''   you are certain that the matching device is plugged, make sure that you did
  '''   call registerHub() at application initialization time.
  ''' </para>
  ''' <para>
  ''' </para>
  ''' </summary>
  ''' <param name="func">
  '''   a string that uniquely characterizes the buzzer, for instance
  '''   <c>YBUZZER2.buzzer</c>.
  ''' </param>
  ''' <returns>
  '''   a <c>YBuzzer</c> object allowing you to drive the buzzer.
  ''' </returns>
  '''/
  Public Function yFindBuzzer(ByVal func As String) As YBuzzer
    Return YBuzzer.FindBuzzer(func)
  End Function

  '''*
  ''' <summary>
  '''   Starts the enumeration of buzzers currently accessible.
  ''' <para>
  '''   Use the method <c>YBuzzer.nextBuzzer()</c> to iterate on
  '''   next buzzers.
  ''' </para>
  ''' </summary>
  ''' <returns>
  '''   a pointer to a <c>YBuzzer</c> object, corresponding to
  '''   the first buzzer currently online, or a <c>Nothing</c> pointer
  '''   if there are none.
  ''' </returns>
  '''/
  Public Function yFirstBuzzer() As YBuzzer
    Return YBuzzer.FirstBuzzer()
  End Function


  REM --- (end of YBuzzer functions)

End Module
