Hi Chris, Firstly, I like to congrats on your latest N+2 which I have been waiting for a long long time. Just like to check is there any other reseller other than the 3 listed on your site? So far, looks like only Amazon has stocks, but it "refuse" to do shipping to Singapore. Any chance from other resellers? Regards, Alex Chan

Hi Novice Alex,


You can safely use the regular Netduino firmware on your Netduino Plus.

To do this you will want to: erase your board by applying 3V3 power to the gold erase pad underneath D0; flash TinyBooter using Atmel SAM-BA; flash the NETMF runtime using MFDeploy.

Full instructions are available on the Wiki.

Once you flash the regular Netduino firmware on your Netduino Plus, you can use the SecretLabs StorageDevice class to ".MountSD" and re-enable SD card access.

Chris

Hi Chris,

Just like to double confirm. I have successfully update the Netduino firmware onto my Neduino+. So when I start a project, do I set it as Netduino/Netduino+ project? Also in my case, do you have any sample code on mounting the SD card.
Also by using Netduino firmware on access SD card, will i be giving up any digital pins access?

Separately, do I need to mount & un-mount the SD card everything I use? Or only for once during system power up?

Thanks in advance.

Hi Novice Alex,


You can safely use the regular Netduino firmware on your Netduino Plus.

To do this you will want to: erase your board by applying 3V3 power to the gold erase pad underneath D0; flash TinyBooter using Atmel SAM-BA; flash the NETMF runtime using MFDeploy.

Full instructions are available on the Wiki.

Once you flash the regular Netduino firmware on your Netduino Plus, you can use the SecretLabs StorageDevice class to ".MountSD" and re-enable SD card access.

Chris

Hi Chris,

Thanks for your quick response.
I will try and revert if there is any problem.

So after this flashing, I suppose I have 128KB code storage size together with 60KB RAM, right?

Hi Chris, Just like to know if it is possible to release more code space if I would to drop the network portion, since for my project, I don't really need it. But I am using Netduino+ because of the SD card reader onboard. If so, how can I go about on loading the firmware, which once should I use? Please advise. Thanks in advance.

Chris, Bingo and Thanks for the great news. Can't wait to get my hands on the upgrade. Care to share when will the >2G SD being integrated for 4.2? Any schedule?

Hi Guys,

Just to share with you guys on my experience on the upgrading to 4.2.
After flashing my Netduino+ I execute the MFDeploy, it does not show the device when I select USB connection.

Then I realize i did not install the latest .NET Micro Framework v4.2 SDK (QFE2).
You may download from here

After installation, reset your netduino and plug it it, you should see the device in the MFDeploy application and continue your firmware upgrade.

Good luck.

Regards,
Alex

Make a call to Math.Pow( a, b )

Do note that latest version does not work for this function.

Hi Guys,

Anyone familiar with VB.net can help with some code on how to detect the SD card been ejected?
I am following this topic, but I can do the same in VB.net. Please help and thanks in advance.

Links on how to detect presence of SD card

That code won't work in VB.NET since it works differently with events. This would work:

Module Module1

    Sub Main()
        AddHandler Microsoft.SPOT.IO.RemovableMedia.Eject, AddressOf RemovableMedia_Eject
        AddHandler Microsoft.SPOT.IO.RemovableMedia.Insert, AddressOf RemovableMedia_Insert
        Thread.Sleep(Timeout.Infinite)
    End Sub

    Sub RemovableMedia_Eject(sender As Object, e As Microsoft.SPOT.IO.MediaEventArgs)
        Debug.Print("Ejected")
    End Sub

    Sub RemovableMedia_Insert(sender As Object, e As Microsoft.SPOT.IO.MediaEventArgs)
        Debug.Print("Inserted")
    End Sub

End Module

Hi Carb & Stefan,

Thank you for your great helps.

Cheers!

Hi Guys, Separately, do you have any sample circuit to connect to N+ for measuring 4-20mA Analog input? Together with sample code will be great. Currently I am using VB.net to handle the 12V pulse input through opto-coupler circuit. Thanks in advance.

What is the issue with your work around?

Seems like it would do what you want, if you use the code a lot you may benefit from wrapping it as a static method

//C#
public static int MinutesDifference(DateTime lastGPSInfo){
 return (DateTime.Now.Subtract(lastGPSInfo).Ticks/TimeSpan.TicksPerMinute);
}

//VB.Net - My VB is very rusty example is from memory so may not work at all ;-)
Public Shared Function MinutesDifference(ByVal lastGPSInfo As DateTime) As Int
 Return (DateTime.Now.Subtract(lastGPSInfo).Ticks/TimeSpan.TicksPerMinute)
End Function

Nak.

Hi Guys,

There is nothing wrong with my workaround, except that it needs more code to do as compare to DateDiff method. As you know code size for our little Netduino is precious.

Hi Guys, in VB.net, when I need to find the time difference between 2 dates, all I need is to use the function DateDiff. But in NetMF, I can only use date.subtract method and it returns a Timespan object. The problem here is that, in a TimeSpan object, how can I get the total number of minutes between 2 dates? In the NetMF, the totalMinutes method is removed. Only left with the Minutes property which does not serve my purpose. So I have to fall back to use the following statements: if (Date.Now.substract(m_dteLastGPSInfo).tick/TimeSpan.TicksPerMinute )> 30 then .... Any good idea on how to deal with this? Thanks in advance.

Hi,

At the first moment, thanks for your time....


I have tryed with


try
Dim a As String = "10"
Dim h As New System.DateTime(1900, 1, 1, CInt(a), CInt(a), 0)
catch e as exception
Debug.print e.message
end try

and i have the next in debug...

Exception was thrown: System.NotImplementedException


I work with

DeviceInfo:
HAL build info: 4.2.0.0, Netduino Plus (v4.2.0.0 RC3) by Secret Labs LLC
OEM Product codes (vendor, model, SKU): 34, 177, 4097
Serial Numbers (module, system):
00000000000000000000000000000000
0000000000000000
Solution Build Info: 4.2.0.0, Netduino Plus (v4.2.0.0 RC3) by Secret Labs LLC
AppDomains:
Assemblies:
mscorlib,4.2.0.0
Microsoft.SPOT.Native,4.2.0.0
Microsoft.SPOT.Hardware,4.2.0.0
Microsoft.SPOT.Net,4.2.0.0
System,4.2.0.0
Microsoft.SPOT.Hardware.SerialPort,4.2.0.0
Microsoft.SPOT.IO,4.2.0.0
System.IO,4.2.0.0
Microsoft.SPOT.Hardware.Usb,4.2.0.0
Microsoft.SPOT.Hardware.PWM,4.2.0.0
SecretLabs.NETMF.Hardware,4.2.0.0
SecretLabs.NETMF.Diagnostics,4.2.0.0
Without SD Card,1.0.0.0
Microsoft.VisualBasic,1.0.0.0
classFecha,1.0.0.0

I have solved this problem with an function in c#, but may be good i can found a better solution.s

thanks in advance.

Just wonder has the 4.2 RC4 solved the VB parse problem.

Hi Moskus,

Can you please post a bug report on this at netmf.codeplex.com?

There are a number of post-release bugfixes being checked into the .NET MF 4.2 codebase. We're hoping to pull a bunch of them in at once and make a Netduino 4.2 RC4 firmware update...so it would be great to get this one in too.

Chris

Hi Chris,

Any timeline for the RC4 firmware?
Please advise.

Novice Alex

Does Interger.Parse("0") not work ?

Does any try out the above using the 4.2 RC4?

Hi Guys, Currently I have developed a near to completed application on the N+ using Netduino firmware (to get the extra RAM). But only today, I realise N+ has a problem reading text file (with around 500 records) of size around 12Kb. I need to read back for historical reporting on daily basis. I am using the streamreader.readtoend method, but it will throw SystemOutofMemory. I also tried using the pre-define size buffer(1024) to read block by block, but still meet the same exception. I also tried using the readline method together with stringbuilder library to join each readline returns. But still hit the same exception. Then I finally give up. I have to reduce my sampling interval to ensure the daily file size is around 6K instead, then everything goes well. Just like to check anyone out there has a better idea how to handle large text file data log files? Thanks in advance. Regards, Novice Alex

Hi Stefan, If I don't do the readtoend method, the process will be very slow and it will cause exception from my interrupt (8 pulse inputs). Do you have any codes on how to do file seek? Maybe, I can use your method, but need to call the read file many times using the seek method to remember where I left off on the previous call.

It all depends on the file format. Since you're writing daily stats? You could do several things:
- Make records an X amount of bytes large
- Create a file format that works with data blocks
- Create an index

I have too little information right now to really be able to help you out.

Hi Stefan,

That's sound like a good idea. Since each records is fit by the format [mins since 00:00 of the day] | [Double value with 3 decimal place]. I can fix string format for both. And use ReadBlock to do it. However, need to do some testing to see whether it improve in processing.

in fact, currently when I read back the full content, I will then pass the full file content (as string) back to the caller for further parsing and then determine the require range (report time start to end) and accumulate the total value in the field (2) - Double.

Regards,
Alex

What are you doing with the file once you have read it?

Regards,
Mark

Hi Mark,

These data files (daily) are records of the engine consumption that sample every 1 mins.
Currently the record format is as follows: [mins since today's 00:00] | [Double variable with 3 decimal places]

Regards,
Alex

Hi Chris, I remember the SD card corruption happens after around 7 days of "burn test". I have been trying to do "hot swap" for newly design PCB to see any effect on the system reliability. Then it starts to hang the whole N+. After putting in a few debug statement, it came to know that it was hang during the writing to a data text file. I have tried to do file deleting on the SD card on my PC, but it still exists after I do a screen refresh. So, no choice but to reformat it. I suppose it can be caused by the loss of power during the writing (while doing the "hot swap"), but how can we recover from there if such incident happens again, given that this system will be deployed to remote sites out in the sea, so it will be quite trouble to access. From my attached class, is there any potential problem that you can foresee? Thanks in advance. Regards, Novice Alex

Hi Guys,

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

The general rule-of-thumb with microcontrollers is that pin assignments aren't always restricted to their architectural labelling. For example, a pin maybe labelled as PWM(Pulse Width Modulator) which would normally tie-in with a hardware clock and hardware interrupts. By default, the pin doesn't function as a PWM unless you actually configure it to be.

Much the same with the CTS and RTS pins, you can configure them as OutputPorts or InterruptPorts. If you try to use them for two purposes, you'll get a runtime exception when trying to initialise the pin for a second use. Example of using the RTS pin as a GPIO pin

SerialPort comPort = (SerialPorts.COM2, 9600, Parity.None, 8, StopBits.One); //Initialise COM2
OutputPort oPort = new OutputPort(Pins.GPIO_PIN_D7, false); //initialise the RTS pin as an output port with logic low as initial value;

Hi Nobby,

wonderful... That clears my doubts.
Just for knowledge, how can I configure PIND7 as RTS, do you have the code for it?

Thanks in advance.

Hi Nobby, Below is my statement. m_objCommMgr = New cCommManager("COM2", 9600, Ports.Parity.None, 8, Ports.StopBits.One) so far, I have not connected RTS and CTS since i am only using 3 wire interface. Since on the board layout, for COM2 it comes with RTS and CTS (derived from GPIO pins), I just wonder if we can disable these RTS and CTS when using COM2. Thus giving my project the much needed GPIO to measure the pulse input. Care to share how do you initialise your COM2 without RTS & CTS? Thanks in advance.

Hi Guys, Need your advice on how to release COM2(CTS, RTS) pins for more GPIO purpose? Currently for my project, I need 2 COM port, but we usually use 3-wire interface, so just like to check how can I release CTS and RTS pins for my other GPIO purpose. Thanks in advance. Regards, Novice Alex

Thanks, I voted for the issue too

Hi Stefan,

They have taken up the issue and fixes is schedule for NETMF 3.0