Hi,
As the title says, I have a problem connecting a HID device to an Android phone. The device I want to communicate with is an ARM based board that I created some years ago and have been using with a PC program and now I want an Android app. I'm using the ADB test project as a base and started modifying it. I changed the InterfaceClass and InterfaceSubClass and it seems to be working with one exception: when I read the data that the device sends back I get only zeros. The boards receives the command from the phone and replies to it, I was able to check that using an ARM debugger. What am I doing wrong?
As the title says, I have a problem connecting a HID device to an Android phone. The device I want to communicate with is an ARM based board that I created some years ago and have been using with a PC program and now I want an Android app. I'm using the ADB test project as a base and started modifying it. I changed the InterfaceClass and InterfaceSubClass and it seems to be working with one exception: when I read the data that the device sends back I get only zeros. The boards receives the command from the phone and replies to it, I was able to check that using an ARM debugger. What am I doing wrong?
B4X:
#Region Module Attributes
#FullScreen: False
#IncludeTitle: True
#ApplicationLabel: USB
#VersionCode: 2
#VersionName: 1.01
#SupportedOrientations: unspecified
#CanInstallToExternalStorage: False
#End Region
Sub Process_Globals
Dim manager As UsbManager
Dim connection As UsbDeviceConnection
Dim outEndpoint, inEndpoint As UsbEndpoint
Dim device As UsbDevice
Dim interface As UsbInterface
Dim MSG_READ, DATA_READ As String
MSG_READ = "Msg-Read" : DATA_READ = "Data-Read"
Dim InRequests, OutRequests As List
End Sub
Sub Globals
Dim btnConnect As Button
Dim btnDisconnect As Button
End Sub
Sub Activity_Create(FirstTime As Boolean)
If FirstTime Then
manager.Initialize
InRequests.Initialize
OutRequests.Initialize
End If
Activity.LoadLayout("1")
End Sub
Sub Activity_Pause(UserClosed As Boolean)
End Sub
Sub btnDisconnect_Click
If connection.IsInitialized Then
connection.StopListening
OutRequests.Clear
InRequests.Clear
Log("Stopped")
End If
End Sub
Sub btnConnect_Click
If connection.IsInitialized = False Then
FindAdbDevice
CheckPermission
End If
End Sub
Sub CheckPermission
If device.IsInitialized Then 'It will only be initialized if a device was found
If manager.HasPermission(device) = False Then
manager.RequestPermission(device)
Else
'There is permission. Connect if neccessary.
If connection.IsInitialized = False Then
MakeConnection
End If
End If
End If
End Sub
Sub Activity_Resume
End Sub
Sub FindAdbDevice As Boolean
Dim usbdevices() As UsbDevice
usbdevices = manager.GetDevices
'Iterate over devices and find the correct one
For i = 0 To usbdevices.Length - 1
Dim ud As UsbDevice
ud = usbdevices(i)
Log(ud)
'Iterate over interfaces
For a = 0 To ud.InterfaceCount - 1
Dim inter As UsbInterface
inter = ud.GetInterface(a)
If inter.InterfaceClass = 3 And inter.InterfaceSubclass = 0 Then
'found our device and interface
device = ud
interface = inter
'Find correct endpoints
For b = 0 To interface.EndpointCount - 1
Dim endpoint As UsbEndpoint
endpoint = interface.GetEndpoint(b)
If endpoint.Type = manager.USB_ENDPOINT_XFER_INT Then
If endpoint.Direction = manager.USB_DIR_IN Then
inEndpoint = endpoint
Else If endpoint.Direction = manager.USB_DIR_OUT Then
outEndpoint = endpoint
End If
End If
Next
End If
Next
Next
If device.IsInitialized = False Then Log("ADB device not found.")
End Sub
Sub MakeConnection
Dim data(64), msg(24) As Byte
connection = manager.OpenDevice(device, interface, True)
Log("Starting connection")
msg = ConvertStringToBytesWith0("#VERSION")
SendOutRequest("Msg", msg)
SendInRequest(MSG_READ, 24)
connection.StartListening("connection")
End Sub
Sub Connection_NewData (Request As UsbRequest, InDirection As Boolean)
If connection.IsInitialized = False Then Return 'Might happen after we close the connection
If InDirection = False Then
ReleaseRequest(Request, OutRequests)
connection.ContinueListening
Return 'don't handle OUT requests
End If
Dim raf As RandomAccessFile
Dim s As String
raf.Initialize3(Request.Buffer, True)
s=""
For i=0 To 23
s=s & raf.ReadUnsignedByte(i)
Next
Log(s)
If Request.Name = MSG_READ Then
Else If Request.Name = DATA_READ Then
End If
ReleaseRequest(Request, InRequests)
connection.ContinueListening
End Sub
Sub ConvertStringToBytesWith0 (S As String) As Byte()
s = s & Chr(0)
Return s.GetBytes("UTF8")
End Sub
Sub SendOutRequest(Name As String, Data() As Byte)
Dim request As UsbRequest
request = GetRequest(True)
request.Name = Name
request.Queue(Data, Data.Length)
End Sub
Sub SendInRequest(Name As String, Length As Int)
Dim request As UsbRequest
request = GetRequest(False)
request.Name = Name
Dim Data(Length) As Byte
request.Queue(Data, Data.Length)
End Sub
Sub GetRequest (Out As Boolean) As UsbRequest
Dim r As UsbRequest
Dim RequestList As List
If Out Then RequestList = OutRequests Else RequestList = InRequests
If RequestList.Size = 0 Then
If Out Then
r.Initialize(connection, outEndpoint)
Else
r.Initialize(connection, inEndpoint)
End If
Else
r = RequestList.Get(0)
RequestList.RemoveAt(0)
End If
Return r
End Sub
Sub ReleaseRequest(Request As UsbRequest, RequestList As List)
RequestList.Add(Request)
End Sub
