B4A Library SoundMeter - Real Time display of Sound Level (dB)

#Region  Project Attributes
    #ApplicationLabel: b4aSoundMeterNew
    #VersionCode: 1
    #VersionName:
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: unspecified
    #CanInstallToExternalStorage: False
#End Region

#AdditionalRes: ..\DemoRes

#Region  Activity Attributes
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.
 
    Dim t As Timer

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.
    Dim bm As Bitmap
    Dim bmd As BitmapDrawable

    Private Button1 As Button
    Private Button2 As Button
    Private sm As SoundMeter
    Dim bufsize As Int = 300                                  'set the data buffer size here i.e how many values to display in the plot area
    Dim xlab(bufsize) As String
 
    Private lc1 As RealTimeLineChart
    Dim a As Int = 0
    Dim xlabeltrack As Int = 0
 
End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    Activity.LoadLayout("main")
    t.Initialize("t", 50)
    bm.Initialize(File.DirAssets, "noise_disc.png")
    bmd.Initialize(bm)
    sm.BackgroundImage = bmd
 
    lc1.GraphTitleColor = Colors.White
    lc1.GraphTitleSkewX = -0.15
    lc1.GraphTitleBold = True
    lc1.GraphTitleTextSize = 15.0
    lc1.GraphPlotAreaBackgroundColor = Colors.Black          'this will paint the plotting area DrakGray regardless of what GraphBackgroundColor has been set to
    lc1.GraphBackgroundColor = Colors.Transparent               'this will paint everything within the outer frame to be white
    lc1.GraphFrameColor = Colors.Red                            'this adjusts only the outer frame color
    lc1.GraphFrameWidth = 2.0
    lc1.GraphBufferSize = bufsize
    lc1.GraphTitle = "Sound Meter"

    lc1.DomainLabelColor = Colors.Cyan
    lc1.DomainLabelTextSize = 25
    lc1.DomianLabel = "Sound Level"
 
    lc1.YaxisRangeMode = lc1.YaxisMode_FIXED                    'the other option is FIXED
    lc1.YaxisRange(40.0, 100.0)
    lc1.YaxisDivisions = 10
    lc1.YaxisLabelTicks = 1
    lc1.YaxisShowZero = True
    lc1.YaxisTitleTextSize = 20.0
    lc1.YaxisTitleColor = Colors.Green
    lc1.YaxisGridLineColor = Colors.Yellow
    lc1.YaxisLabelTextSize = 20
    lc1.YaxisLabelColor = Colors.Green
    lc1.YaxisLabelOrientation = 0
    lc1.YaxisTitle = "dB"
 
    '************************ If you comment this code then the x-axis labels will be the index value of the buffer
    For i = 0 To bufsize - 1
        xlab(i) = "" & i
    Next
    lc1.XAxisLabels = xlab
    '*************************************************************************************************************
     
    lc1.XaxisLabelTextSize = 20
    lc1.XaxisLabelTextColor = Colors.Cyan
    lc1.XaxisGridLineColor = Colors.Yellow
    lc1.XaxisLabelOrientation = 0
    lc1.XaxisDivisions = 30
    lc1.XaxisLabelTicks = 1

 
    lc1.LegendTextSize = 15.0
    lc1.LegendTextColor = Colors.White
    lc1.LegendBackgroundColor = Colors.Transparent
 
    'setup for Line 1
    lc1.Line_1_LineColor = Colors.Red
    lc1.Line_1_LineWidth = 3.0
    lc1.Line_1_DrawDash = False
    lc1.Line_1_LegendText = ""

    lc1.NumberOfLineCharts = 1
    lc1.DrawTheGraphs
 
 
End Sub

Sub Activity_Resume

    lc1.START

End Sub

Sub Activity_Pause (UserClosed As Boolean)
 

End Sub


Sub Button1_Click
    t.Enabled = True
    sm.StartdB
 
End Sub

Sub Button2_Click
 
    sm.StopdB
    t.Enabled = False
 
End Sub

Sub t_tick


    lc1.addData(sm.dBValue, 0, 0, 0, 0)
    a = a + 1
    If a = 301 Then a = 0
 
    If xlabeltrack = bufsize + 1 Then
        xlabeltrack = 0
        lc1.ClearAllData                        'THIS WILL CLEAR THE DATA
        a = 0
        For i = 0 To bufsize - 1
            xlab(i) = "" & i
        Next
        lc1.XAxisLabels = xlab
        lc1.DrawTheGraphs
        lc1.START
    End If
 
    '************************ If you comment this code then the x-axis labels will be the index of the buffer
'    xlabeltrack = xlabeltrack + 1
'    If xlabeltrack > bufsize Then
'        xlab = shiftarray(xlab)
'        xlab(bufsize - 1) = "" & xlabeltrack
'        lc1.XAxisLabels = xlab
'    End If
'    xlab(bufsize - 1) = "" & xlabeltrack
    '**************************************************************************************************************
 
End Sub

Sub shiftarray (oldarray() As String) As String()
 
    Dim newarray(bufsize)
    For i = 0 To bufsize - 2
        newarray(i) = oldarray(i + 1)
    Next
    Return newarray
 
End Sub