Control of Serial Port

[DrStrangeLv]

See script below

What I'm having problems with is getting the port to open and close.

Within the loop I need to be able to open port , keep it open for a set time
then close the port.
Re-cal to open port time
and then re-do the loop process.

I "noob" at this and very sure I've done something wrong.

What does happen is it open the port once , goes through the loop and at end of loop closes port.


Thank you to any who can assist.

Sub Globals
'Declare the global variables here.

Dim EVtemp
Dim FinalEV
Dim SHUTTER_METERED
Dim intDelay
Dim Shoot
Dim Total_Exposures
Total_Exposures = 0
Dim Expos_Begin_Counter
Dim Begin_Exposure_Speed
Dim Current
Current = " "
Shot_Count = 0
tempcount = 0

Dim ex
ex=0
Exposures.text=0
Dim dly
dly=0
Delay.text=0
Dim nm
nm=0
NumerMeter.text=0
Dim dm
dm=0
DenumMeter.text=0
Dim nev
nev=0
NumerEV.text=0
Dim Minutes_Between_Shots



End Sub

Sub App_Start
Shooter.Show
serial.New1
'***serial.New2 (1,9600,"N",8,1)

End Sub


Sub Button1_Click
Current.Text = " "
serial.PortOpen = True
Shot_Count = 0
Dim ex
ex=Exposures.text
Dim dly
dly=Delay.text
Dim nm
nm=NumerMeter.text
Dim dm
dm=DenumMeter.text
Dim nev
nev=NumerEV.text
Minutes_Between_Shots = (Minutes.Text * 60 )*1000 Total_Exposures = ex

' ***Do Math Below***
Expos_Begin_Counter = ((ex - 1)/2)
EVtemp = nev
SHUTTER_METERED = nm / dm
If EVtemp * 2 <= 1 Then
FinalEV = (EVtemp + 1)*2
Else
FinalEV = Evtemp * 2
End If


If SHUTTER_METERED < 1 Then '***Test for Whole Seconds***

Begin_Exposure_Speed = dm

Do While Expos_Begin_Counter > 0 '***Do Fraction Routine here***
Begin_Exposure_Speed = Begin_Exposure_Speed / FinalEV

Expos_Begin_Counter = Expos_Begin_Counter - 1 Loop

' ***Do Suhtter Routine Below***
This_Exposure = Begin_Exposure_Speed

Shot_Count = 1

Computed_Time = 1 / This_Exposure


'***Loop for port open close
Do While Shot_Count <= Total_Exposures
Sleep((dly * 1000))

serial.DTREnable = True '***open port date send
Sleep(Computed_Time * 1000) '***hold port open for time
serial.DTREnable = False '***close port


'***re-cal time and bump up loop count
This_Exposure = This_Exposure * 2
Computed_Time = 1 / This_Exposure
Shot_Count = Shot_Count + 1
Loop

Else
'***If Whole Seconds do whole second routine***

End If
Sleep((dly * 1000))
Current.Text = "Done"
serial.PortOpen = False
End Sub

 

[Softselect]

Here is a copy of my commented test program for the serial port
Hope it helps
Friedrich

 

[Zenerdiode]

I'm guessing your shutter is opening as soon as the program is run? If so, its because as soon as the Port is opened; the DTR line will be high.

Choose which pin you are going to use as the shutter control pin. I suggest DTR. Remember that according to the hardware of the serial port you use, when the DTR line is asserted it will be at a positive voltage and when disabled it could be the same magnitude but negative, 0V or anything else. You really need to check with a multimeter as to what your PDA is giving out. Do a simple app with say, a checkbox to check what is going on with your port. (I found with mine, when asserted it gave +6.5V and when disabled -6.5V. I use mine with a signal diode and drive an instrumentation relay to provide a 'volt free contact' to interface to whatever I like.)

To get around the DTR being high when the port is opened, in your App_Start;

Sub App_Start
   Serial.New1
   Serial.DTREnable=False 'These have to come
   Serial.RTSEnable=False 'before PortOpen=True
   Serial.PortOpen=True
   Shooter.Show
End Sub

'In subsequent Subs, set DTR to True and False as required.

Also, it may just be peculiar to my PDA, but I found I locked everything up once because the Serial Port didn't close properly. It doesn't harm to add:

Sub Shooter_Close
   Serial.Dispose
End Sub

**DO NOT** use PortOpen to control your shutter, leave it open and control your chosen line, (eg DTR)

 

[DrStrangeLv]

This explains a great deal of whats been happening.
The manual does not describe serial use to well but both of you have made things much clearer.

Many thanks

Jim

 

[mjcoon]

Here is a copy of my commented test program for the serial port
Hope it helps
Friedrich

Hi Friedrich, I thought your program might help me to find out what is happening with a 3rd-party program I have tried.

But when I tried to run your SBP on my device I got a "native exception" in B4PPC and details:
ExceptionCode: 0xc0000005
ExceptionAddress: 0x01258fc8
Reading: 0x00000004

I don't suppose this means anything to you (unless you happened tohave seen it yourself) so I will have to ask a B4PPC expert...

Cheers, Mike.

 

[Softselect]

Hi Mike,
I am by no means an expert, but the program i wrote was for the desktop not the device, you will have to change the dll's for the device
unfortunately I dont have a device with me so i cant test it, but when i get back home in a weeks time i can try it for you, but i am sure you would have come right by then
thanks Friedrich

Sorry Mike I am talking straw, the device was an HP with serial port, my confusion is that i normaly only use com on the desktop, i will find the last program for the device that I used an post it later
Thanks Friedrich

 

[Softselect]

hi mike,
try this copy, it has DBCOMM.dll added, it may solve your problem
under tools, add components, add dll
thanks Friedrich