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I have done up a commercial project and now doing the "burn test".
This project suppose to do data logging of the fuel consumption from different flow meters on a 5 mins interval.
However, I found that randomly the log file could be corrupted and it will cause the whole N+ to hang when accessing it.
I have tried to access the SD card using my PC and can see that that particular "problem" file exists but I am not able to access it and I can't delete it from my PC. So the only way is to reformat my SD card and start fresh. This gives me some sense of "uncertainty".
Does anyone know how can we handle such cases to avoid the N+ to hang? By the way, when I say hang, it means not even when I short the reset pin to ground or press the reset can restart N+, the only way is to power it down completely.
Below is my SD card class library.
Imports System.IO
Imports SecretLabs.NETMF.Hardware.Netduino
Imports SecretLabs.NETMF.Hardware
Imports Microsoft.SPOT
Public Class cSDCard
#Region "Enumeration"
#End Region
#Region "Declaration"
Public Shared Event LastError(ex As Exception)
Public Shared Event SDEject()
Private Shared m_bSDEjected As Boolean = True
#End Region
#Region "Property"
Public Shared Property SD_Ejected() As Boolean
Get
Return m_bSDEjected
End Get
Set(value As Boolean)
m_bSDEjected = value
End Set
End Property
#End Region
#Region "Method"
Public Shared Function MountSD() As Boolean
MountSD = False
SD_Ejected = True
Try
SecretLabs.NETMF.IO.StorageDevice.MountSD("SD", Microsoft.SPOT.Hardware.SPI.SPI_module.SPI2, 21, 57)
Dim dirinfo As New DirectoryInfo("\SD")
If (dirinfo.Exists) Then
MountSD = True
SD_Ejected = False
End If
Catch ex As Exception
SD_Ejected = True
End Try
End Function
Public Shared Function UnMountSD() As Boolean
Try
If SD_Ejected = True Then
Exit Function
End If
SecretLabs.NETMF.IO.StorageDevice.Unmount("SD")
Catch ex As Exception
End Try
End Function
Public Shared Function ReadFile(sFilename As String, ByRef sContent As String, Optional bReadLastLineOnly As Boolean = False) As Boolean
ReadFile = False
Try
Dim lFileSize As Long = 0
Dim sTmp As String = ""
sContent = ""
If SD_Ejected = True Then
Exit Function
End If
If File.Exists(sFilename) Then
Dim myFile As New StreamReader(New FileStream(sFilename, FileMode.Open, FileAccess.Read))
If bReadLastLineOnly = True Then
While (1)
sTmp = myFile.ReadLine
If Not sTmp Is Nothing Then
sContent = sTmp
Else
Exit While
End If
End While
Else
sContent = myFile.ReadToEnd
End If
myFile.Close()
Else
Debug.Print(sFilename & " not found!!!")
End If
ReadFile = True
Catch ex As Exception
RaiseEvent LastError(ex)
End Try
End Function
Public Shared Function WriteFile(sFilename As String, sContent As String, Optional bAppend As Boolean = True) As Boolean
WriteFile = False
Try
If SD_Ejected = True Then
Exit Function
End If
Dim myFile As StreamWriter
If bAppend = True Then
myFile = New StreamWriter(New FileStream(sFilename, FileMode.OpenOrCreate, FileAccess.Write))
Else
DeleteFile(sFilename)
myFile = New StreamWriter(New FileStream(sFilename, FileMode.CreateNew, FileAccess.Write))
End If
myFile.WriteLine(sContent)
myFile.Close()
WriteFile = True
Catch ex As Exception
RaiseEvent LastError(ex)
End Try
End Function
Public Shared Function DeleteFile(sFilename As String) As Boolean
DeleteFile = False
Try
If SD_Ejected = True Then
Exit Function
End If
If File.Exists(sFilename) Then
File.Delete(sFilename)
End If
DeleteFile = True
Catch ex As Exception
RaiseEvent LastError(ex)
End Try
End Function
#End Region
End Class
Thanks in advance.
Regards,
Alex Chan
