BS2 and Servo Question

Archiver

I am trying to controll servos from a VB application, I can't seem to
get it figured out. Here is some snips, anyone have any ideas?

the Stamp Code
'{$STAMP BS2}
pinnumber var byte
servopos var byte
main:
Serin 16,16780,[noparse][[/noparse]WAIT(255),pinnumber,servopos]

pulsout pinnumber, (750 + servopos)

pause 15
goto main


The VB code
Private Sub cmdSend_Click()
Dim PinNumber As Long
Dim servopos As Long
servopos = Val(txtvalue.Text)

' Get Pin Number
PinNumber = cboPinNumber.ListIndex

' Send Out Data
MSComm1.Output = Chr$(255) & Chr$(PinNumber) & Chr$(servopos)
End Sub


servopos comes from a slider controll set at min 25 and max 254, not
sure if these are right but I have tried many values and nothing
works. Anyone have any ideas????

Archiver

Part of the problem is that to move the servo through its full swing, you
need to send values between 500 and 1000 with PULSOUT. That means the value
that is passed to your servo routine needs to be between -250 and +250 ... a
byte variable can't hold anything but positive values (0 - 255).

To keep things simple, I would have your VB slider send a value between 0 and
500; 250 being the center point. Your servo update routine would change to:

PULSOUT pinNumber, (500 + servoPos)

Then, your servoPos value needs to be a Word (two bytes), so you'll have to
modify your SERIN line.

Or ... you could keep the servoPos variable a Byte and pass a servo position
value between 0 and 250 (125 is the center now). Then change your servo
update code to this:

PULSOUT pinNumber, (500 + (servoPos * 2))


I hope this helps.

-- Jon Williams
-- Applications Engineer, Parallax

In a message dated 7/22/02 1:38:07 AM Central Daylight Time,
joebiederman@h... writes:


> I am trying to controll servos from a VB application, I can't seem to
> get it figured out. Here is some snips, anyone have any ideas?
>
> the Stamp Code
> '{$STAMP BS2}
> pinnumber var byte
> servopos var byte
> main:
> Serin 16,16780,[noparse][[/noparse]WAIT(255),pinnumber,servopos]
>
> pulsout pinnumber, (750 + servopos)
>
> pause 15
> goto main
>
>
> The VB code
> Private Sub cmdSend_Click()
> Dim PinNumber As Long
> Dim servopos As Long
> servopos = Val(txtvalue.Text)
>
> ' Get Pin Number
> PinNumber = cboPinNumber.ListIndex
>
> ' Send Out Data
> MSComm1.Output = Chr$(255) & Chr$(PinNumber) & Chr$(servopos)
> End Sub
>
>
> servopos comes from a slider controll set at min 25 and max 254, not
> sure if these are right but I have tried many values and nothing
>




[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

Thats helps tremendously, thanks a million!

--- In basicstamps@y..., jonwms@a... wrote:
> Part of the problem is that to move the servo through its full
swing, you
> need to send values between 500 and 1000 with PULSOUT. That means
the value
> that is passed to your servo routine needs to be between -250 and
+250 ... a
> byte variable can't hold anything but positive values (0 - 255).
>
> To keep things simple, I would have your VB slider send a value
between 0 and
> 500; 250 being the center point. Your servo update routine would
change to:
>
> PULSOUT pinNumber, (500 + servoPos)
>
> Then, your servoPos value needs to be a Word (two bytes), so you'll
have to
> modify your SERIN line.
>
> Or ... you could keep the servoPos variable a Byte and pass a servo
position
> value between 0 and 250 (125 is the center now). Then change your
servo
> update code to this:
>
> PULSOUT pinNumber, (500 + (servoPos * 2))
>
>
> I hope this helps.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
>
> In a message dated 7/22/02 1:38:07 AM Central Daylight Time,
> joebiederman@h... writes:
>
>
> > I am trying to controll servos from a VB application, I can't
seem to
> > get it figured out. Here is some snips, anyone have any ideas?
> >
> > the Stamp Code
> > '{$STAMP BS2}
> > pinnumber var byte
> > servopos var byte
> > main:
> > Serin 16,16780,[noparse][[/noparse]WAIT(255),pinnumber,servopos]
> >
> > pulsout pinnumber, (750 + servopos)
> >
> > pause 15
> > goto main
> >
> >
> > The VB code
> > Private Sub cmdSend_Click()
> > Dim PinNumber As Long
> > Dim servopos As Long
> > servopos = Val(txtvalue.Text)
> >
> > ' Get Pin Number
> > PinNumber = cboPinNumber.ListIndex
> >
> > ' Send Out Data
> > MSComm1.Output = Chr$(255) & Chr$(PinNumber) & Chr$(servopos)
> > End Sub
> >
> >
> > servopos comes from a slider controll set at min 25 and max 254,
not
> > sure if these are right but I have tried many values and nothing
> >
>
>
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

Seems to be working ok, I posted the code below. It won't let me
update the servo position very fast. Anyone have any ideas?

Stamp code
'{$STAMP BS2}
pinnumber var byte
servopos var byte
cont var byte
b var byte
main:
Serin 16,16780,[noparse][[/noparse]WAIT(255),pinnumber,servopos]
for b = 1 to 50
pulsout pinnumber, (500 + (servopos * 2))
pause 10
next
goto main


VB Code

Private Sub cmdcenter_Click()
sldpos.Value = 125
End Sub

Private Sub Form_Load()
Dim Pins As Long
' Add the pin numbers 0 to 15 to cboPinNumber
For Pins = 0 To 15
cboPinNumber.AddItem CStr(Pins)
Next Pins

' Default to Pin 0 being selected
cboPinNumber.ListIndex = 0

' Default to optState(0) being selected


' Use COM1
MSComm1.CommPort = 1

' 2400 baud, no parity, 8 data bits, 1 stop bit
MSComm1.Settings = "2400,N,8,1"

' Open the port
MSComm1.PortOpen = True

End Sub
Private Sub cmdSend_Click()
Dim PinNumber As Long
Dim servopos As Long
servopos = sldpos.Value


' Get Pin Number
PinNumber = cboPinNumber.ListIndex

' Send Out Data
MSComm1.Output = Chr$(255) & Chr$(PinNumber) & Chr$(servopos)

End Sub
Private Sub Form_Unload(Cancel As Integer)
MSComm1.PortOpen = False
End Sub

Private Sub sldpos_change()
cmdSend_Click
End Sub






--- In basicstamps@y..., "quasigeek2002" <joebiederman@h...> wrote:
> Thats helps tremendously, thanks a million!
>
> --- In basicstamps@y..., jonwms@a... wrote:
> > Part of the problem is that to move the servo through its full
> swing, you
> > need to send values between 500 and 1000 with PULSOUT. That
means
> the value
> > that is passed to your servo routine needs to be between -250 and
> +250 ... a
> > byte variable can't hold anything but positive values (0 - 255).
> >
> > To keep things simple, I would have your VB slider send a value
> between 0 and
> > 500; 250 being the center point. Your servo update routine would
> change to:
> >
> > PULSOUT pinNumber, (500 + servoPos)
> >
> > Then, your servoPos value needs to be a Word (two bytes), so
you'll
> have to
> > modify your SERIN line.
> >
> > Or ... you could keep the servoPos variable a Byte and pass a
servo
> position
> > value between 0 and 250 (125 is the center now). Then change
your
> servo
> > update code to this:
> >
> > PULSOUT pinNumber, (500 + (servoPos * 2))
> >
> >
> > I hope this helps.
> >
> > -- Jon Williams
> > -- Applications Engineer, Parallax
> >
> > In a message dated 7/22/02 1:38:07 AM Central Daylight Time,
> > joebiederman@h... writes:
> >
> >
> > > I am trying to controll servos from a VB application, I can't
> seem to
> > > get it figured out. Here is some snips, anyone have any ideas?
> > >
> > > the Stamp Code
> > > '{$STAMP BS2}
> > > pinnumber var byte
> > > servopos var byte
> > > main:
> > > Serin 16,16780,[noparse][[/noparse]WAIT(255),pinnumber,servopos]
> > >
> > > pulsout pinnumber, (750 + servopos)
> > >
> > > pause 15
> > > goto main
> > >
> > >
> > > The VB code
> > > Private Sub cmdSend_Click()
> > > Dim PinNumber As Long
> > > Dim servopos As Long
> > > servopos = Val(txtvalue.Text)
> > >
> > > ' Get Pin Number
> > > PinNumber = cboPinNumber.ListIndex
> > >
> > > ' Send Out Data
> > > MSComm1.Output = Chr$(255) & Chr$(PinNumber) &
Chr$(servopos)
> > > End Sub
> > >
> > >
> > > servopos comes from a slider controll set at min 25 and max
254,
> not
> > > sure if these are right but I have tried many values and
nothing
> > >
> >
> >
> >
> >
> > [noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

You're waiting on the PC to send something. You could add a timeout to the
SERIN so that the servos get updated if nothing new is sent from the PC. You
could also use a timer on the PC side to continuously send the servo values
(in case the Stamp is doing something else and misses and update from the
PC). Lastly, you could use a "full" serial port with flow control.

I'll be working on that last part (pc connection with flow control) myself in
the next couple of weeks for an upcoming Nuts & Volts article.

-- Jon Williams
-- Applications Engineer, Parallax

In a message dated 7/22/02 12:24:50 PM Central Daylight Time,
joebiederman@h... writes:


> Seems to be working ok, I posted the code below. It won't let me
>




[noparse][[/noparse]Non-text portions of this message have been removed]