1
'name iPod Remote Interface
2'author Daniel M. Story
3'package iPod Interface
4'copyright 2007
5'version 1.0
6
7Imports System
8Imports System.IO
9Imports System.IO.Ports
10
11
Public Class iPodRemoteClass iPodRemote
12
Private WithEvents CommPort As SerialPort
13
14 Public Event PlayButton_Down()
15 Public Event PlayButton_Up()
16 Public Event StopButton_Down()
17 Public Event StopButton_Up()
18 Public Event SkipForwardButton_Down()
19 Public Event SkipForwardButton_Up()
20 Public Event SkipBackwardButton_Down()
21 Public Event SkipBackwardButton_Up()
22 Public Event VolumeUpButton_Down()
23 Public Event VolumeUpButton_Up()
24 Public Event VolumeDownButton_Down()
25 Public Event VolumeDownButton_Up()
26
27 Private LastButton As Short
28 Private buffer As ArrayList
29
30
Public Sub New()Sub New()
31 buffer = New ArrayList
32 CommPort = New SerialPort()
33 CommPort.BaudRate = 19200
34
End Sub
35
36 Public Property Port()Property Port() As String
37 Get
38 Return CommPort.PortName
39 End Get
40 Set(ByVal value As String)
41 CommPort.PortName = value
42 End Set
43 End Property
44
45 Public Sub Open()Sub Open()
46 CommPort.Open()
47 End Sub
48
49 Public Sub Close()Sub Close()
50 CommPort.Close()
51 End Sub
52
53 Private Sub CommPort_DataReceived()Sub CommPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles CommPort.DataReceived
54 Dim i As Integer
55 Dim BufferData() As Byte
56 ReDim BufferData(CommPort.BytesToRead - 1) 'redefine data size to fit entire response
57 If CommPort.Read(BufferData, 0, BufferData.Length) Then
58 For i = 0 To (BufferData.Length - 1)
59 buffer.Add(CByte(BufferData(i)))
60 Next i
61 ParseBuffer()
62 End If
63 End Sub
64
65 Private Sub ParseBuffer()Sub ParseBuffer()
66 'All thanks to: http://ipodlinux.org/Apple_Accessory_Protocol
67
68 Dim Header As Short '= 0xff55 (aka 22015)
69 Dim Length As Byte '= len(mode + command + parameters)
70 Dim Mode As Byte '= command category/mode
71 Dim Command As Short '= command/function
72 Dim Parameter() As Byte '= optional parameter
73 Dim Checksum As Byte '= 0x100 - ( (sum of length, mode, command, and parameters) & 0xFF)
74
75 Dim ParameterLength As Byte
76 ReDim Parameter(0)
77
78 Dim DataSum As Integer '= the datasum to get the checksum
79 Dim MyChecksum As Byte '= the checksum I calculated
80 Dim i As Integer '= for looping
81 Dim offset As Integer
82
83 Do
84 Header = BitConverter.ToInt16(New Byte() {Convert.ToByte(buffer.Item(offset)), Convert.ToByte(buffer.Item(offset + 1))}, 0) 'convert the header to a short (16bit)
85 If Header = 22015 Then 'is the correct header?
86 If (buffer.Count - offset) < 7 Then Exit Do 'safety check
87 Length = Convert.ToByte(buffer.Item(offset + 2))
88 Mode = Convert.ToByte(buffer.Item(offset + 3))
89 Command = BitConverter.ToInt16(New Byte() {Convert.ToByte(buffer.Item(offset + 4)), Convert.ToByte(buffer.Item(offset + 5))}, 0)
90 ParameterLength = Length - 3
91 If (buffer.Count - offset) < 7 + ParameterLength Then Exit Do 'safety check
92 If ParameterLength > 0 Then 'if have parameters (shouldn't matter since the simple remote never sends it)
93 ReDim Parameter(ParameterLength - 1)
94 For i = 0 To (ParameterLength - 1)
95 Parameter(i) = Convert.ToByte(buffer.Item(offset + (i + 5)))
96 Next i
97 End If
98 Checksum = Convert.ToByte(buffer.Item(offset + 6))
99 'all that stuff just separates the data byte array into its categories
100
101 DataSum = 0
102 For i = 2 To Length + 2
103 DataSum += Convert.ToByte(buffer.Item(offset + i))
104 Next i
105 ' get the data sum (for calc-ing the sum [up next])
106
107 MyChecksum = &H100 - ((DataSum) And &HFF)
108 'calc the checksum of what was received
109 If MyChecksum = Checksum Then 'check it to see if anythign failed.
110 'Debug.Print(Command.ToString)
111 Select Case Command
112 Case 0
113 'released
114 Raise_LastButton()
115 Case 256
116 'play
117 If LastButton <> 0 Then
118 If LastButton <> Command Then Raise_LastButton()
119 End If
120 If LastButton <> Command Then RaiseEvent PlayButton_Down()
121 Case 512
122 'vol +
123 If LastButton <> 0 Then
124 If LastButton <> Command Then Raise_LastButton()
125 End If
126 If LastButton <> Command Then RaiseEvent VolumeUpButton_Down()
127 Case 1024
128 'vol -
129 If LastButton <> 0 Then
130 If LastButton <> Command Then Raise_LastButton()
131 End If
132 If LastButton <> Command Then RaiseEvent VolumeDownButton_Down()
133 Case 2048
134 'skip >
135 If LastButton <> 0 Then
136 If LastButton <> Command Then Raise_LastButton()
137 End If
138 If LastButton <> Command Then RaiseEvent SkipForwardButton_Down()
139 Case 4096
140 'skip <
141 If LastButton <> 0 Then
142 If LastButton <> Command Then Raise_LastButton()
143 End If
144 If LastButton <> Command Then RaiseEvent SkipBackwardButton_Down()
145 Case -32768
146 'stop
147 If LastButton <> 0 Then
148 If LastButton <> Command Then Raise_LastButton()
149 End If
150 If LastButton <> Command Then RaiseEvent StopButton_Down()
151 End Select
152 LastButton = Command
153 End If
154 For i = 0 To (Length + 2)
155 buffer.RemoveAt(offset)
156 Next i
157 Else
158 offset += 1
159 End If
160 Loop While (offset < (buffer.Count - 1))
161 End Sub
162
163 Private Sub Raise_LastButton()Sub Raise_LastButton()
164 Select Case LastButton
165 Case 256
166 'play
167 RaiseEvent PlayButton_Up()
168 Case 512
169 'vol +
170 RaiseEvent VolumeUpButton_Up()
171 Case 1024
172 'vol -
173 RaiseEvent VolumeDownButton_Up()
174 Case 2048
175 'skip >
176 RaiseEvent SkipForwardButton_Up()
177 Case 4096
178 'skip <
179 RaiseEvent SkipBackwardButton_Up()
180 Case -32768
181 'stop (my remote doesn't have this button, so couldn't test)
182 RaiseEvent StopButton_Up()
183 End Select
184 LastButton = 0
185 End Sub
186
187 Protected Overrides Sub Finalize()Sub Finalize()
188 MyBase.Finalize()
189 If Not CommPort Is Nothing Then If CommPort.IsOpen Then CommPort.Close()
190 CommPort.Dispose()
191 CommPort = Nothing
192 End Sub
193
End Class