hi,
Well done!.

Download from a Google, the Pinout for the Printer connector.
It will give you the port addressess and which pins are which. example: 378, 379 and 37A.

Its important you get this port pin info, you will need it.

No, the pins are not 'powerful' enough to drive motors or relays, [try a LED]

Thats why you need the PCB I keep on about, you will need to put transistors and other components on, if you want to drive motors.

Do you have a dc power supply, say about 12Vdc, you will need something to power your motors.

Let me know when you have the pin outs.

Eric

EDIT: added a *.pdf that have used for port work

 

I have the 12 V dc supply

pls, help me in making the PCB!
a diagram or anything with a list of what i'll need

 

hi,

A couple of questions.

Do you have a specific project in mind? Example: drive a LED or Relay or a small DC motor.

If yes, then what LED's, motors do you have, if any. ?

I would suggest that you look at a hobbyist catalog and find a prototyping board, the type you just push the components into pin sockets. [no soldering].

Are you now confident you can switch the pins on the parallel port using VB.?
Did you try the LED ?
Did you get the parallel.pdf downloaded to your PC?

Its important that you give us the answers so we can advise.

I can tell that you very keen to 'get going' on the project, but plan what you intend doing.
It will save you time and money in the long run.

EDIT: Google for 'parallel port projects' there are many projects to choose, also tutorials.

Eric

 

If yes, then what LED's, motors do you have, if any. ?
yes, i have everything ! my dad is an electronics engg. but he neither encourages nor does he help me with my dream projects (like this)

I know how to solder!!!! I am the one who always represents my school in robotics in the UAE , so i'm familiar with it!

yes , i do have a final aim !

' i want to control a series of motors through my computer!

For eg. when i click a button , first motor#1 should run for 10 secs , then motor# 2 for another 2 sec along with moto# 3 and so on.....'

Are you now confident you can switch the pins on the parallel port using VB.? ....pin #2 , yes i am confident. but rest of the pins- i don't know!

Did you try the LED ?... yes it did work switching on/ off ! !! really!

Did you get the parallel.pdf downloaded to your PC? yes i downloaded it , but it sounds very strange to me....lilke greek!!!

 

can you tell me how to find out the port address of every pin!

 

hi,
Attached pinout of port connector.

Pins 2 to 9 are output pins [ 8 in all] and ground [0v] pins 18 to 25.
These pins can be used to drive transistors/logic devices, they are TTL outputs, Low or High
[ 0v or +5v, you will find if you use your DC meter, that the voltage levels are around 0.4v and 4.5v]

As you want to drive outputs just consider these 8 pins at first, you can use the other input/output pins later on.

Use the VB program from yesterday to drive these 8 output lines. Sending a 0 or 255 will switch them all low/high.

To switch just 1 line, say pin2, send 0 or 1. to switch two lines,say 1 and 2 send 0 and 3. On address 378.

As you can now see its a 8 bit binary pattern, sending 0 and 15 [00001111] will switch pins 2,3,4,5 low/high. Got the idea?.

Buy a piece of copper strip board [PCB], the type that has a 0.1inch hole pattern and copper tracks on one side,
running the length of the PCB. Size say, 100mm *160mm.

A range of resistors, common values for LED's 330R. Transistor biasing 2K2, 4K7, 10K0. A range of capacitors, 1000nF, 0.1uF, 1uF.
Transistors about 4, general purpose 30V, 200mA, NPN and PNP types.
Motors, 2, small DC motors with a voltage rating to suit your DC power supply.

Signal diodes 4, 1N914 or equivalent, rectifier diodes 1N4001 100v 1A or equivalent.

When you have these parts, let me know, I'll post some circuits.

Eric

 

Hey!! thanx Eric!!!!!!!
Now i understand the idea behind the pins!!
thank you so much

but it take a lot of time for me to calculate and find out the data (converting from binary to numbers) !! otherwise i'm confident

ok ! i have a few PCBs already!

And bout the parts - i'l be getting them within another 4-5 hrs

 

Eric,
1 doubt- what does the pcb do?

why dont i just use a relay to activate a switch and work the motor using a 9V in a different circuit ?
is there any mistake?pls correct me if any!

Do u get a 5v relay? to get activated by the voltage from the parallel port ?

 

hi,

The pcb is the board that you will solder your components to.

If you get the 0.1inch hole pitch, copper stripboard, you will use a soldering iron to mount/solder the components to the board. [pcb]

Also the wires fron the end of your printer cable will be soldered to the board so that they connect with your components, OK?

Always make you circuits neat and tidy, dont cramp all the components in one corner of the board, it makes fault finding a nightmare.

I've already done a rough drawing for you.
You should try to do the 'layout' of the components yourself, Let me know.

Eric

EDIT: Dont connect a motor or relay to the port connector wires!. You could damage your PC's port.
ALWAYS use a transistor to drive a relay or motor

 

hi,
Added two parts to drawing.

One is an Input to your VB program, its Pin #13. 'select' line.[bit#4. 00010000] Address 379 when the VB prog reads.
PB#1 is a push button switch.

Be SURE to use the 6K8 and 10K0 resistor values, dont exceed +5v input to the port.

The second part is an optional +3v to +9v psu for other projects.

Eric

 

If You have a Form in VB with a textbox to put the data that you want in the lpt output then just write a number .... for example...

If you want to turn on just the pin # D0 then just type 1 in the textbox.
if you want to turn on the pin # D1 type 2

Here is a table that may helps...

Text box nummer LPT Out(or binary)
1 = 10000000
2 = 01000000
3 = 1100000
4 = 00100000
5 = 10100000
And if you want the # D4 wich is the 5th pin then yust type:
16 = 00001000

__________________
Gromikov: http://circuits.4000webs.com

 

hi gromikov,

Could you please explain this:

Here is a table that may helps...

Text box nummer LPT Out(or binary)
1 = 10000000
2 = 01000000
3 = 1100000
4 = 00100000
5 = 10100000
And if you want the # D4 wich is the 5th pin then yust type:
16 = 00001000

Eric

 

I made some projects working with VB and the LPT of the computer...
My VB Form contained a textbox where you could type a number (decimal) and that number was the output in the LPT in its (binary). That goes automatically, you don't need a special code for the conversion and that because of the machine language.

Due the explained above :

If you type the number 1 (for example), inside the textbox in your VB form, you will have in the LPT Output the binary code for "1" which is "10000000" or if you want to write it the other way "00000001"

The output pins are from
D0 to D7 or pin 2 to pin 9



You just need the right File.Dll for your Windows Version which can be inpout32.dll or IO.dll.
And A BV form with a button and a a textbox...... the button has to tell the form to write the data contained in the textbox to the LPT address.

I Hope this helps .

__________________
Gromikov: http://circuits.4000webs.com

 

hi,

I have the inpout32.dll which I use for all my parallel port projects.

Ive tried the 'example' as you have posted it, it dosn't work for me!.

If you type the number 1 (for example), inside the textbox in your VB form, you will have in the LPT Output the binary code for "1" which is "10000000" or if you want to write it the other way "00000001"

What you are saying 11000000 is the same as 00000011, if its binary how can it select pin #2 and #3 in both cases?

As another forum member got this to work?

Eric

 

to convert binary to numerals - ( i learnt it from my computer text book )

the formula is sum of (0 or 1) * 2^(n-1) where n is the place of the digit from the right.

eg

01000000 = (0*2^7) + (1* 2^6) + (0*2^5) + (0*2^4) + ........ (0*2^0)
= 2^6
= 64
when you enter the data as 64 for port 378 then pin 8 will be activated.