VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   5175
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   8520
   FillColor       =   &H00C0C0C0&
   FillStyle       =   0  'Solid
   LinkTopic       =   "Form1"
   ScaleHeight     =   5175
   ScaleWidth      =   8520
   StartUpPosition =   3  'Windows Default
   Begin VB.Timer RateTimer 
      Left            =   0
      Top             =   4320
   End
   Begin VB.TextBox Comment 
      Height          =   525
      Left            =   6000
      MultiLine       =   -1  'True
      TabIndex        =   10
      Text            =   "Main.frx":0000
      Top             =   360
      Width           =   2175
   End
   Begin VB.CheckBox AutoTrigger 
      Caption         =   "AutoSet"
      Height          =   315
      Left            =   3360
      TabIndex        =   9
      Top             =   600
      Value           =   1  'Checked
      Width           =   975
   End
   Begin VB.TextBox HeartRate 
      Height          =   285
      Left            =   4800
      TabIndex        =   6
      Text            =   "Text3"
      Top             =   360
      Width           =   975
   End
   Begin VB.TextBox TriggerLevel 
      Enabled         =   0   'False
      Height          =   285
      Left            =   3360
      TabIndex        =   5
      Text            =   ".5"
      Top             =   360
      Width           =   975
   End
   Begin VB.PictureBox Picture1 
      Appearance      =   0  'Flat
      AutoRedraw      =   -1  'True
      BackColor       =   &H8000000A&
      ForeColor       =   &H80000008&
      Height          =   3975
      Left            =   240
      ScaleHeight     =   263
      ScaleMode       =   3  'Pixel
      ScaleWidth      =   527
      TabIndex        =   4
      Top             =   960
      Width           =   7935
   End
   Begin VB.TextBox Text1 
      Height          =   285
      Left            =   4800
      TabIndex        =   3
      Text            =   "Text1"
      Top             =   600
      Width           =   975
   End
   Begin VB.Timer Timer1 
      Left            =   0
      Top             =   3840
   End
   Begin VB.TextBox Buffer 
      Height          =   285
      Left            =   2040
      TabIndex        =   1
      Text            =   "6"
      Top             =   360
      Width           =   855
   End
   Begin VB.CommandButton Command1 
      Caption         =   "Start Recording"
      Height          =   375
      Left            =   240
      TabIndex        =   0
      Top             =   240
      Width           =   1575
   End
   Begin VB.Label Label3 
      Caption         =   "Heart Rate"
      Height          =   255
      Left            =   4800
      TabIndex        =   8
      Top             =   120
      Width           =   975
   End
   Begin VB.Label Label2 
      Caption         =   "Trigger Level"
      Height          =   255
      Left            =   3360
      TabIndex        =   7
      Top             =   120
      Width           =   975
   End
   Begin VB.Label Label1 
      Caption         =   "Graph time (sec)"
      Height          =   255
      Left            =   2040
      TabIndex        =   2
      Top             =   120
      Width           =   1215
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
' ---------------------------------------------------------------------------
' Constants that may be user-setable in the future
' ---------------------------------------------------------------------------

' You can set these.  Changing number of channels and bits per sample will
' sort of screw up the oscilloscope, though.  Actually, changing the bits
' per sample may screw up some other things too, though nothing that'd be
' particularly hard to fix.

' Number of channels to record (1 = mono, 2 = stereo)
Private Const pcNumberOfChannels As Long = 1

' Sample rate (Hz)
Private Const pcSamplesPerSecond As Long = 44100

' Maximum number of seconds to buffer the input
Private Const pcMaxSeconds As Integer = 20

' The amount of gap to put in the graph
Private Const pcGap As Integer = 20

' ---------------------------------------------------------------------------


' Various global variables - not user setable

' Bits per sample
Private Const pcBitsPerSample As Long = 16

' Handle of the open audio device.  0 when not capturing.
Private pDevHandle As Long
' Pointer to the memory heap containing the wave from the input
'Private pWaveHeap As Long
' Pointer to the memory block in the heap that I can use
'Private pWaveMem As Long
' The wave input header
Private pWaveHeader As WAVEHDR
' The data of the input wave
Private data(pcSamplesPerSecond * pcMaxSeconds) As Integer
' Pointer to the data
Private pData As Long
' The maximum value of Y for the sweep
Private maxY As Long


Private Sub AutoTrigger_Click()
    If (AutoTrigger.Value = 1) Then
        TriggerLevel.Enabled = False
    Else
        TriggerLevel.Enabled = True
    End If
End Sub

Private Sub Buffer_LostFocus()
    ' This sets the number of seconds to buffer the input
    
    If (Buffer.Text > pcMaxSeconds) Or (Buffer.Text < 0.5) Then
        MsgBox "Value must be between 1 and" + Str(pcMaxSeconds) + " seconds", vbExclamation
        Buffer.Text = 6
    End If
End Sub


Private Sub Form_Load()
    Picture1.FillColor = Form1.BackColor
    Picture1.FillStyle = 0
    prevX = 0
End Sub

Private Sub Form_Resize()
    If (Form1.ScaleWidth > 490) Then
        Picture1.Width = Form1.ScaleWidth - 480
    End If
    If (Form1.ScaleHeight > 960 + 250) Then
        Picture1.Height = Form1.ScaleHeight - 960 - 240
    End If
    Picture1.ScaleTop = -(Picture1.ScaleHeight / 2)
    'Picture1.Line (0, 0)-(Picture1.ScaleWidth / 2, Picture1.ScaleHeight / 2)
End Sub


Private Sub Command1_Click()
    If (Command1.Caption = "Start Recording") Then
        Start_recording 'Caption gets changed in the subroutine
        Buffer.Enabled = False
    Else
        Command1.Caption = "Start Recording"
        Stop_Recording
        Buffer.Enabled = True
    End If
    
End Sub


Private Sub Start_recording()

' Set some variables
    Dim msg As String * 255     ' Error messages go here
    Dim WF As WAVEFORMAT
    With WF
        .wFormatTag = WAVE_FORMAT_PCM
        .nChannels = pcNumberOfChannels
        .nSamplesPerSec = pcSamplesPerSecond
        .wBitsPerSample = pcBitsPerSample
        .nBlockAlign = (.nChannels * .wBitsPerSample) \ 8
        .nAvgBytesPerSec = .nBlockAlign * .nSamplesPerSec
        .cbSize = 0
    End With

'Obsolete - I found another way to save the memory
' Allocate the amount of memory needed to store the data (add a little for all the headroom)
'    pWaveHeap = HeapCreate(0, pcSamplesPerSecond * 2 * Buffer.Text + 1000, 0)
'    If (pWaveHeap = Null) Then
'        MsgBox "Could not allocate " + Str(pcSamplesPerSecond * 2 * Buffer.Text + 1000) + "bytes of memory", vbExclamation
'        Exit Sub
'    End If
'    pWaveMem = HeapAlloc(pWaveHeap, HEAP_ZERO_MEMORY, pcSamplesPerSecond * 2 * Buffer.Text)
'    If (pWaveMem = Null) Then
'        MsgBox "Error allocating the memory in the heap", vbExclamation
'        Exit Sub
'    End If
    
'An easier way to create and access the memory
    pData = VarPtr(data(0))