logic circuit FOr DC motors control & strobe

[tannazii]

I wanna to Design an interface by using LPT port for on/off DC motors & give status of them by strobe signal.

 

[TekUT]

If you're searching some way to change the pin state of a port on PC you can also use the DTR signal over the serial port and RTS as input one. This task is easy to do also by using Visual Basic using the well know MSComm object.

With MSComm1
 .CommPort = 1                               
 .Settings = "9600,N,8,1"                    
 .InBufferSize = 1024
 .Handshaking = comNone
 .RThreshold = 1
 .SThreshold = 0
 .InputLen = 1
 .InputMode = comInputModeText
 .PortOpen = True
 .DTREnable = False
End With

then drive the line high or low with these command (take also in mind that low level was -12 V and high +12 V)

MSComm1.DTREnable = True    ' To switch on
MSComm1.DTREnable = False   ' To switch off

Using printer port especially trough latest Win32 environment like Win2k, WinXP, Vista require more effor due to the kernel restriction, you need to use specialized library able to work on Ring 0.
If you like to use the parallel port look at this thread, there is some useful information for your task:


Hope it help
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