Serial VB 2005 pic 16f877a problems

[ardhuru]

I can see the PC trying to send out on the scope but it does not get stored in my pic variable. I even ran a wire from the tx side of the pic to the rx and still nothing. The pic is sending but not recieving.
Snap

I have found this http://www.serial-port-monitor.com/index.html utility extremely useful while doing anything with VB and the serial port.

Also, if you have another serial port, try and read what your VB code is in fact sending although serial port monitor would do the same anyway.

Regards,

Anand

[T.Jackson]

Don't ever leave this forum mister_e, my life depends on you being here sharing your knowledge. I think I speak for everyone.

[Snap]

Hello again, Ok I switched off the adc'd with adcon1 statement.
And that must have done something because now everytime I start the program it locks up at the display temp part.
If I remove the serin code it works (just the program not the recieve signal from the PC)
If I remove the wire from the serin port to the rx on the max 232 adapter it works
This is all when the PC is not even plugged in the the max 232
the wire seems to be shorting out the program or the signal is screwing it up
To me the USART seems to be more work then a simple serin command why would I use it?
here is the pic code

Include "MODEDEFS.BAS"
DEFINE LCD_DREG  PORTB
DEFINE LCD_DBIT   0
DEFINE LCD_RSREG  PORTB
DEFINE LCD_RSBIT 5
DEFINE LCD_EREG  PORTD
DEFINE LCD_EBIT 7
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATUS 50
ADCON1=%00000111

'
RST var portd.2
DQ var portd.0
CLK var portd.1
temp var word 'storage for temperature
pcsig var word


'
low rst 'reset 1620
'
lcdout $fe,1,"Temp in Degrees C"

' Main loop
mainloop:
RST = 1'enable device might be high
Shiftout DQ,CLK,LSBFIRST,[$ee] 'send read command
RST = 0 ' reset device
Pause 1000 ' wait for conversion to compleate
'
RST = 1 ' SAA
Shiftout DQ,CLK,LSBFIRST, [$aa] ' send read command
Shiftin DQ,CLK,LSBPRE, [temp\9]'read 9 bits temp
RST = 0
'
lcdout $fe,1,dec(temp>>1), ".", dec(temp.0*5), " Degrees C"
pause 1000
serout portd.3,t2400,[#temp]
pause 1000
serin porta.1,t2400,pcsig
if pcsig > 1 then high porta.1

lcdout $fe,1,pcsig,"pcsig"
pause 1000

goto mainloop

END

Here is the VB code
I ommitted a class

  Public Class Form1
    Dim WithEvents serialport As New IO.Ports.SerialPort
    Dim temperature As Integer

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If serialport.IsOpen Then
            serialport.Close()

        End If
        With serialport
            .PortName = "com1"
            .BaudRate = 2400
            .Parity = IO.Ports.Parity.None
            .DataBits = 8
            .StopBits = IO.Ports.StopBits.One
            '.DtrEnable = True
            '.ReadBufferSize = 40
            .ReceivedBytesThreshold = 2
        End With
        serialport.Open()

    End Sub
    Private Sub Datarecieved(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles serialport.DataReceived
        TextBox1.Invoke(New mydelegate(AddressOf updatetextbox), New Object() {})

    End Sub
    Public Delegate Sub mydelegate()
    Public Sub updatetextbox()


        Dim mytemp As New temp
        mytemp.binary = serialport.ReadExisting
        Dim resultc As Decimal = celciusconversion(mytemp.binary)
        Dim resultf As Decimal = farconversion(resultc)
        TextBox1.Text = resultc
        TextBox2.Text = resultf
        If resultc >= 24 Then
            'serialport.Write("a")
            serialport.Write(100)
            TextBox3.BackColor = Color.Green
            TextBox3.Text = "fan on"
        Else
            TextBox3.BackColor = Color.Red
            TextBox3.Text = "fan off"
        End If




    End Sub
    Public Function celciusconversion(ByVal datarecieved As String) As Decimal
        Return datarecieved * 0.5
    End Function

    Public Function farconversion(ByVal datarecieved As String) As Decimal
        Return (datarecieved * 1.8) + 32
    End Function

Thank you for your time.
I am trying to help out on this forum as much as I can, I have been sending copies of my slot car timer to users who ask for it.

[mister_e]

serialport.Write(100)

this should send string, so i guess you'll need to change the SERIN to

serin porta.1,t2400,#pcsig

I'll second Ardhuru's advice. A serial COMport sniffer is always handy to have on hand. I use HHDSoft's one
http://www.hhdsoftware.com

There's a load of those here and there, some are 100% free.

Having one on hand... priceless!

[Snap]

Thanks for the reply but the problem is that the program is now (after fixing port a) locking up as soon as I connect the rx pin on the 232 adapter, the serial cable is not even connected and it locks up.
if i comment out the serin code with the 232 connected it works (without serin)
I think the serin command is locking up the program but I don't know why.
The voltage is always 5 volts untill a code comes threw would a constant 5 volts mess up the serin pin? this is a falling trigger do i need to tell the pic what type to look for?
t2400 ? n2400?
I hope I have given enough information, I have been.
what would cause the program to lock up as soon as i connect the serin pin?

thanks again

[mister_e]

Well that's strange indeed, why it locks... well it will lock anyways until you have some valid data.

You said you're using a MAX232 and you're capable of sending data to your PC... T2400 is the setting. Weird enough.. my computer don't work with such low baudrates...

serout portd.3,t2400,[#temp]
pause 1000
serin porta.1,t2400,pcsig

i would suggest to remove the pause 1000, and change your SERIN line

serout portd.3,t2400,[#temp]
serin porta.1,t2400,#pcsig

[skimask]

what would cause the program to lock up as soon as i connect the serin pin?

Post #20 here...http://www.picbasic.co.uk/forum/show...ght=serin+idle
might help you out a bit...

Or this might:
http://www.picbasic.co.uk/forum/show...highlight=idle

[mister_e]

Valid for Timeout use...