VB 2005 and BS2 -- why won't the signal stop after I close connection?

Comments

• Mike G Posts: 2,702

  2011-06-13 15:25 edited 2011-06-13 15:25

  Turn off STAMP 1?
  
  Otherwise send a message to STAMP2 when you click the Stop button. Stamp 2 will need to look for the message and turn off/on accordingly.
• tbare Posts: 13

  2011-06-13 17:07 edited 2011-06-13 17:07

  In theory, that would work, but in practice, i can't just "shut off the press" before i click "stop" in my app.
  
  additionally, if i do just "turn off the stamp," when i turn it back on, it goes right back to what it was doing. The only way to get it to stop is to unplug the usb cable, and plug it back in.
  
  what is the code to turn off / on the stamp? that is more or less what i'm looking for.
• Unsoundcode Posts: 1,532

  2011-06-14 08:40 edited 2011-06-14 08:40

  Hi, for serial communications I would say that the SEROUT and SERIN commands are much more flexible than DEBUG. If you want to receive information at the PC from the Stamp and also issue commands to the Stamp, such as stop start etc., you will need to devise some kind of simple protocol. Here is a link to some VB examples. http://forums.parallax.com/showthread.php?96973-VB-Express-to-Stamp-Template
  
  Jeff T.
• tbare Posts: 13

  2011-06-14 14:34 edited 2011-06-14 14:34

  Thanks -- it looks like SERIN and SEROUT is what i'm looking for.
  
  As a complete self-proclaimed rookie, and being under a relative time-crunch, how would i do something like the following:
  
  IF SERIN ... [DEC 1]
  loop and output for each impression -- probably use similar BUTTON code that i currently have
  UNTIL SERIN [DEC 2]
  
  basically, once it receives a 1, look for button presses until it receives a 2, then wait for the next 1...
  
  Any push in the right direction (or flat out code) would be greatly appreciated... they're wanting this thing done as quick as possible (and they asked the new guy whom they knew had no experience with EEPROMs to do it..)
  
  EDIT:
  forgot to mention that i've looked at the Nuts & Volts chapter on Serin & Serout dmystified, as well as several other pages, but am running out of time on this.. I am trying to learn, promise!
• Mike G Posts: 2,702

  2011-06-14 14:46 edited 2011-06-14 14:46

  tbare wrote:

  what is the code to turn off / on the stamp? that is more or less what i'm looking for.

  The help file contains PBasic syntax and code examples. Here's a very simple loop.
  

  ' {$STAMP BS2p}
  ' {$PBASIC 2.5}
  
  result          VAR   Byte
  
  ' Initialize to ASCII "0"
  result = $30
  
  Main:
    ' Wait 5 seconds for inout from the PC
    ' jump to no data if we timeout
    ' else send an acknowledge "!" to let the PC know we
    ' received the data.
    ' Also echo the command.
    SERIN 16, 1021, 5000, No_Data, [result]
    SEROUT 16, 1021, ["!"]
    SEROUT 16, 1021, [result]
  
  No_Data:
    'Process if result equals "1" or ASCII $31
    IF result = $31 THEN
      SEROUT 16, 1021, ["HELLO", CR]
    ENDIF
  
  GOTO Main
  
  

  
  The VB logic needs to resend 0x30 (anything other than 0x31) if the acknowledge character is not received within some period of time (timeout). Once "!" is received then proceed to close the port. The STAMP does not handle parallel tasks. It could be working on something else when the VB app sends the stop command.
  
  When you open the port, send 0x31 until the "!" is received.
  
  Notice the PBasic logic is echoing the command. That's because you're listening for the Data_ Received event which is executing on a secondary thread. When you see a "!" the next byte is the last command. I'd roll up a listener (delegate) in the button close/open event and fire off an event when the "!" is received. You can also save the state of which button was pressed, then when you see the "!", read the state and handle.
  
  You could poll the serial port over using the SerialPort.DataReceived event. Polling will be a little easier.
  
  [Edit]: This is .NET source I used for testing cross platform serial port communication. It uses a timer to poll the serial port because Mono (on Linux) does not implement the DataReceived event. It's C# though.
• Mike G Posts: 2,702

  2011-06-14 18:02 edited 2011-06-14 18:02

  tbare, I just noticed... this is bad.
  

      Private Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles COMPort.DataReceived
          Counter += 1
          Call updateText(Counter)
          If Counter Mod 200 = 0 Then
              COMPort.Close()
              COMPort.Open()
          End If
      End Sub
  

  
  I'm guessing that you're closing the port after 200 DataReceived events to clear the receive buffer? You're asking for trouble. Also there is not guarantee that impression count = DataReceived count. Consider reading the buffer and making a decision on the data received.
• tbare Posts: 13

  2011-06-15 06:34 edited 2011-06-15 06:34

  yeah -- basically, after about 4000 impressions, my counter would go crazy, and start spinning like a stopwatch. after i closed and re-opened the port after every 200 counts, the problem went away... I think the buffer things is a better way to go. I'll look into that and see if i can clear the buffer on the stamp itself, rather than close / open.
  
  Thanks again for all the help! again, being a rookie in a new game is always difficult.
• Mike G Posts: 2,702

  2011-06-15 08:34 edited 2011-06-15 08:34

  tbare, the buffer is in the PC not the STAMP. The STAMP does not have a buffer.
  
  Anyway, the .NET and PBasic code provided has what you need to complete the project. Did you, by chance, run the code?
• tbare Posts: 13

  2011-06-15 10:43 edited 2011-06-15 10:43

  yeah - the code is working.. Thanks a ton.
  
  If I run into anything else, I'll post back.
  
  again, the help is MUCH appreciated!
• tbare Posts: 13

  2011-06-17 07:05 edited 2011-06-17 07:05

  Hey, Mike -- In what version of VB did you write the C# code? I tried opening it in my VB 2005, but it said it was newer. Just wondering what version i need to install on a test machine so I can see what you did. I'm still having some issues getting my VB app to get the "!" back...
  
  EDIT - I got pulled onto a more pressing project -- i haven't been working on this non-stop since my last post.. just throwin' that out there...
• tbare Posts: 13

  2011-06-17 07:42 edited 2011-06-17 07:42

  Never mind... i think i got that part... unfortunately, my app is still locking up after it closes -- I've put stops in to try to track down what's happening, but write after it closes the connection, it just freezes... I'll have to track it down.
  
  here's my stop code, though:
  

      Private Sub btnStop_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStop.Click
          Dim wrt As Byte = 0
          If COMPort.IsOpen = True Then
              While (True)
                  COMPort.WriteLine(wrt)
                  Thread.Sleep(50)
                  If COMPort.ReadExisting.ToString.Contains("!") Then Exit While
              End While
              COMPort.Close()
          End If
      End Sub
  

  
  and here's my BASIC stamp:

  ' {$STAMP BS2}
  ' {$PBASIC 2.5}
  
  result          VAR   Byte
  recdResult      VAR   Byte
  result2         VAR   Byte
  btnwrk          VAR   Byte
  Btn             PIN   0
  red             PIN   10
  green           PIN   11
  
  result    = 0
  result2   = 1
  
  ' Flash LEDs
  HIGH red
  PAUSE 250
  LOW red
  PAUSE 250
  HIGH green
  PAUSE 250
  LOW green
  
  Main:
    SERIN 16, 16468, 2, StartCounting, [DEC result]
    recdResult = result
    result = 0
    SEROUT 16, 16468, ["!"]
  
  
  StartCounting:
    'Process if result equals "1" or ASCII $31
    IF recdResult = 1 THEN
      LOW red
      HIGH green
      'SEROUT 16, 1021, [38]
  
      BUTTON Btn, 1, 255, 20, btnwrk, 0, No_Press : DEBUG "*" 'send * to output for each impression
  
      No_Press:
        GOTO Main
  
    ENDIF
  
   IF recdResult = 0 THEN
     LOW green
     HIGH red
     'SEROUT 16, 16468, ["!"]
   ENDIF
  
  GOTO Main
  
• tbare Posts: 13

  2011-06-17 08:05 edited 2011-06-17 08:05

  So, if I add a MsgBox("blah") right before my COMPort.Close(), the msgbox takes various amounts of time to appear (b/w 1/4 second and 3 seconds), but it always closes, and never locks.
  
  Any thoughts as to what may causing this, and a good solution to bypass it w/out a msgbox? I've tried a thread.sleep(4000), but it doesn't help... I'm sure i could do a loop for a few seconds, but that seems like a bad work-around.
  
  Thanks!
• Mike G Posts: 2,702

  2011-06-17 09:33 edited 2011-06-17 09:33

  tbare, the C# code (not VB) was written in Visual Studio 2010. I can convert it to 2005 if you like or you can download C# Express from Microsoft. The syntax will remain C#.
  

  Any thoughts as to what may causing this, and a good solution to bypass it w/out a msgbox?

  I'm guessing you're having a problem understanding multi-threaded applications. It's hard to tell with out seeing all your code.
  

  SERIN 16, 16468, 2, StartCounting, [DEC result]
  

  
  Change the baud to 2400 max (16780) and remove the DEC formatter from [DEC result].
  

  STAMP Manual wrote:

  *The BS2, BS2e and BS2pe may have trouble synchronizing with the incoming serial stream
  at this rate and higher due to the lack of a hardware input buffer. Use only simple variables
  and no formatters to try to solve this problem.
• tbare Posts: 13

  2011-06-17 10:59 edited 2011-06-17 10:59

  Here's the full testing code:
  

  Imports System
  Imports System.IO.Ports.SerialPort
  Imports System.IO.Ports
  Imports System.Threading
  
  Public Class Form1
      Delegate Sub SetTextCallback(ByVal [text] As String) 'to change the text with threadging
      Public WithEvents COMPort As New System.IO.Ports.SerialPort
      Public Counter As Integer = 0
      Public PortAvailable As Boolean = False
      Public StampReturned As String = ""
  
      Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
          Dim ports As String() = GetPortNames()
          Dim com As String = "COM4"
  
          ' Check each available COM port for specified port
          Dim port As String
          For Each port In ports
              If port = com Then
                  COMPort.PortName = com
                  COMPort.BaudRate = 9600
                  COMPort.DataBits = 8
                  COMPort.Parity = IO.Ports.Parity.None
                  COMPort.StopBits = IO.Ports.StopBits.One
                  PortAvailable = True
              End If
          Next port
          If PortAvailable Then
          Else
              MsgBox(com & " not available")
              End
          End If
      End Sub
  
      Private Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles COMPort.DataReceived
          If COMPort.ReadExisting.ToString.Contains("!") = False Then
              Call updateText2(COMPort.ReadExisting.ToString)
              Counter += 1
              Call updateText(Counter)
              If Counter Mod 200 = 0 Then
                  COMPort.DiscardInBuffer()
                  COMPort.DiscardOutBuffer()
              End If
          End If
      End Sub
  
      Private Sub updateText(ByVal [Text] As String)
          If Me.lblComOut.InvokeRequired Then
              Dim d As New SetTextCallback(AddressOf updateText)
              Me.Invoke(d, New Object() {[Text]})
          Else
              Me.lblComOut.Text = [Text]
          End If
      End Sub
  
      Private Sub updateText2(ByVal [Text] As String)
          If Me.TextBox1.InvokeRequired Then
              Dim d As New SetTextCallback(AddressOf updateText2)
              Me.Invoke(d, New Object() {[Text]})
          Else
              Me.TextBox1.Text = [Text]
          End If
      End Sub
  
      Private Sub btnStop_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStop.Click
          Dim wrt As Byte = 0
          If COMPort.IsOpen = True Then
              While (True)
                  COMPort.WriteLine(wrt)
                  Thread.Sleep(5)
                  If COMPort.ReadExisting.ToString.Contains("!") Then Exit While
              End While
              'Thread.Sleep(2000)
              If COMPort.IsOpen = True Then
                  MsgBox("here")
                  COMPort.Close()
              End If
          End If
      End Sub
  
  
      Private Sub btnGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGo.Click
          If COMPort.IsOpen = False Then
              COMPort.Open()
          End If
          Dim wrt As Byte = 1
          If COMPort.IsOpen = True Then
              While (True)
                  COMPort.WriteLine(wrt)
                  Thread.Sleep(5)
                  If COMPort.ReadExisting.ToString.Contains("!") Then Exit While
              End While
          End If
      End Sub
  
  End Class
  

  
  and the stamp:
  

  ' {$STAMP BS2}
  ' {$PBASIC 2.5}
  
  result          VAR   Byte
  recdResult      VAR   Byte
  result2         VAR   Byte
  btnwrk          VAR   Byte
  Btn             PIN   0
  red             PIN   10
  green           PIN   11
  
  result    = 0
  result2   = 1
  
  ' Flash LEDs
  HIGH red
  PAUSE 250
  LOW red
  PAUSE 250
  HIGH green
  PAUSE 250
  LOW green
  
  Main:
    SERIN 16, 16468, 2, StartCounting, [DEC result]
    recdResult = result
    result = 0
    SEROUT 16, 16468, ["!"] 'message received
  
  
  StartCounting:
    'Process if result equals "1" or ASCII $31
    IF recdResult = 1 THEN
      LOW red
      HIGH green
      'SEROUT 16, 1021, [38]
  
      BUTTON Btn, 1, 255, 20, btnwrk, 0, No_Press : SEROUT 16, 16468, ["*"] 'send * to output for each impression
  
      No_Press:
        GOTO Main
  
    ENDIF
  
   IF recdResult = 0 THEN
     LOW green
     HIGH red
   ENDIF
  
  GOTO Main
  

  
  Everything is working as expected now, except the stop - I'll look more into the multi-threading, as i agree that this is probably where i'm having my issues.
  
  like i said, the counter works as expected, just closing the connection doesn't... if I comment out the "COMPort.Close()" line, it works fine, still... but wouldn't that be bad form to leave the connection open like that? seems like a bad idea. I'd much rather open and close the connection for each use.
  
  As far as 2010, i'm pretty sure we have a copy i can use for testing under our ActionPack. I'll check. and converting from C# to VB.NET isn't an issue...
  
  Thanks again for all your help.
• Mike G Posts: 2,702

  2011-06-17 11:36 edited 2011-06-17 11:36

  There are three glaring issues with your code.
  
  1) Counter is counting the number of DataReceived events not the number of impressions from a press!
  2) You're receiving data but not reading the data, just plopping it on the screen.
  3) The DataReceived handler is operating on a secondary thread while the btnStop_Click handler is invoked for the primary thread.
  
  Clicking the Stop button invokes a write to the serial port from the primary thread. The primary is put to sleep for 5ms but DataReceived handler is not asleep!
• Unsoundcode Posts: 1,532

  2011-06-17 11:54 edited 2011-06-17 11:54

  Great observations from Mike and such an easy thing to miss. One way you could handle it is to create a boolean variable that is a condition for all running processes you want to stop when you close the port.
  
  for example
  
  Dim Port_Closing As Boolean=True
  
  When you open the port:-
  
  Port_Closing=False
  
  In you Data Received event:-
  
  If Not Port_Closing Then
  
  ****Do your receiving here****
  
  End If
  
  And when you close the port:
  
  Port_Closing=True
  
  add a short delay here to allow time for everything to finish
  
  Jeff T.
• tbare Posts: 13

  2011-06-17 11:57 edited 2011-06-17 11:57

  1) for each impression, the press closes a circuit simulating a button press - this is why i'm ussing BUTTON for this task - I've tested this on the press, and i get the desired result.
  2) This is my test app - I don't actually care "what" the information is during the DataRecieved handler - but if there is data recieved, i'm counting it as an impression, adding 1 to a variable, then every 250, writing it out to a database, with a final count written out when the stop button is pushed. - the data doesn't have to be perfect, but it needs to be closer than what they're getting now (which isn't counting any waste at all...)
  
  3) -- let's focus on this one, as it appears to be the bulk of the issue. I'm not very familiar with threading, so my question is how do you know that it's on a secondary thread? Any thoughts on how I would resolve this mistake?
• tbare Posts: 13

  2011-06-17 12:07 edited 2011-06-17 12:07

  Jeff -
  
  I tried your suggestion w/ the PortClosing boolean, but it still locks, even with a 5 second sleep after i set the boolean to true and before i attempt to close the port.
  

  Private Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles COMPort.DataReceived
          If COMPort.ReadExisting.ToString.Contains("!") = False And PortClosing = False Then
              Call updateText2(COMPort.ReadExisting.ToString)
              Counter += 1
              Call updateText(Counter)
              If Counter Mod 200 = 0 Then
                  COMPort.DiscardInBuffer()
                  COMPort.DiscardOutBuffer()
              End If
          ElseIf PortClosing = True Then
              COMPort.DiscardInBuffer()
              COMPort.DiscardOutBuffer()
          End If
      End Sub
  
      Private Sub btnStop_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStop.Click
          Dim wrt As Byte = 0
          If COMPort.IsOpen = True Then
              While (True)
                  COMPort.WriteLine(wrt)
                  Thread.Sleep(5)
                  If COMPort.ReadExisting.ToString.Contains("!") Then Exit While
              End While
              PortClosing = True
              Thread.Sleep(5000)
              If COMPort.IsOpen = True Then
                  'MsgBox("here")
                  COMPort.Close()
              End If
          End If
      End Sub
  
      Private Sub btnGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGo.Click
          PortClosing = False
           {snip}
      End Sub
  

  
  i'm sure it's still the multi-threading issue - i just don't know how to resolve it.
  
  Thanks.
• Mike G Posts: 2,702

  2011-06-17 13:53 edited 2011-06-17 13:53

  Working within your constraints from #18, the easiest thing to do is programmaticly remove the COMPort.DataReceived delegate when the Close button is clicked. Then repeatedly issue the close message and listen (polling) until you get the acknowledgement byte from the STAMP. Clean up your objects and close the port.
  
  Remember to assign the COMPort.DataReceived delegate to SerialPort_DataReceived when the Open button is clicked.