Parallel Port...

I have read all faq's and anything else for parallel port and visual basic.

I have a few question about parallel port.

How can i send and recieve signal in parallel port.
How can i send a singal in one pin of 25 in parallel port and how can i get a singal from one pin.
I dont want to send files or somethink else.
I want to contol the 25 pins and sent on it voltage and get from parallel port this signal.

I try to show you how can i think it

|---------------------------|
|. . . . . . . . . . . . .<-- Pin 13
| . . . . . . . . . . . . |
|---------------------------|

How can i sent and recieve the voltage in this pin or in other's pins

Thanks...

[Edited by Civil78 on 05-06-2000 at 10:42 AM]

[Edited by Civil78 on 05-06-2000 at 10:47 AM]

I think youll find it very hard to send voltages to specific pins, but the MSComm control can detect incoming info from COM and LPT ports

Something like that is really more suited to be written in C. It still isn't easy but it's at least possible.

Windows supports only parallel port for the use of printing. Windows has no need to for the parallel port for any other purpose, so it only has drivers and API calls to support data tranfer and communication for printing. I don't know too much about programming the parallel port, but there must be some API call to be used to send an activate High signal to a certain pin.

Also I think there are controls you can buy to support the parallel port.

The serial port has the ablility to this through the MSComm control. But serial port only uses -12v as LOW and +12v as High. There is no 0v Low signal, except the GND pin.
You can change the voltage signal by using external electronic component. (Some cutting and soldering is required).

Note:

Which connectors are for serial and parallel in the back of the computer?

Parallel - 25 pin female
Serial - 25 pin male, 9 pin male

I know I've answered this question at least 10 times on this forum, and frankly I'm getting a little tired of it. Go to http://www.lvr.com/parport.html (I've even got the address memorized). Download inpout32.zip and use the code in the readme, or if you get the energy to search for it in VB-World do that, and you can output to the parallel port. Basically you can only control pins 2-9 of the parallel port using "Out PORTADDRESS, NUMBER" where the pins are 1,2,4,8,16,32,64,128. To get more than one pin on, add the two together and out that value. Just put the + in 2-9, and the minus in 19-25 (doesn't matter which, it's all the same ground).

Sorry if I'm kind of pissy. I'm really tired, and I've answered this a lot.

bob

You can have 12 outputs and 5 inputs in a standard parallel port:

&H888 - gives you 8 outputs
&H889 - gives you 5 inputs
&H890 - this gives another 4 outputs.

Addresses may vary from PC to PC, but these are the most usuals.

In an enhanced parallel port (ECP) you have the 8 bits bidirectional, so you can use either as in/out.

It's almost trivial to send signals to individual pins so as to control lights, motors, etc. Only experienced techs must deal with circuits involving 110 or 220 Volts, however, due to risk of danger to the PC or personal injury. In the market there are boards that isolate the PC from the power line and allow you to control external power devices with easy.

Regards.