hi friends i am doing my last year project n i need your help i am stuck at a point where i have to control stepper motor using only 2 data pins of parallel port remaining 6 data pins i have used for other purpose n i cant mess with those remaining 6 pins so plz help m to find a way to drive stepper motor using two data pins ,i want help with only hardware part as i am a student of information technology branch i am good with programming ......

 

Perhaps you could use the output from the two pins in a BCD format. That would give you four distinct numbers. Each of those four numbers could represent one winding in the stepper motor. Then, you could use a BCD to decimal decoder circuit to control each winding individually. This would only allow single stepping the motor, but perhaps that is sufficient for your project.

 

thank you for ur reply sir bt can u brief m lil more because im new bee in this

 

By using a 'step motor driver' IC, all that is needed is two pins/signals. One pin/signal is a pulsed signal that controls the speed that the motor turns. The second pin/signal is a steady state, either high or low that controls the direction, clockwise or counter clockwise.

 

can i use 4017 decade counter for this purpose as it provide sequential output if yes pls brief me

 

bi-polar or uni-polar stepper motor?
Voltage/amp rating of stepper?
Can you get ground from those other pins?

For proper stepper operation you need 3 pins really.. The step pin, The direction pin and a ground.

 

You don't say what type motor you have, unipolar or bipolar. Or the specifications for the motor. A unipolar motor is easier to work with, if you have a choice.

The good thing about using a stepper driver IC, is that all of the logic and power transistors are contained in the IC. It's not as simple as just a sequential out put. But the driver IC makes it pretty simple.

 

i have 6 wire steper motor which can be used in both unipolar n bipolar mode and it can handle input voltage till 12 v but i am providing 5 volts, here is an images showing my circuit ,i have connected output q0,q1,q2,q3 to 4 inputs of ULN 2003 ic n remaining output including reset in exhibit i have made ground,i am providing clock from one data pin of parallel port by toggling output on data pin i was able to carry out the working by only one data pin n it actually worked for 15 - 16 min (full rotation with a millisecond gap) after that something went wrong nw motor is not working it's giving a slight jerks but not rotating fully .

 

You can drive a 5-wire stepping motor with just two outputs. You cycle two outputs using a Gray code, 0-1-3-2-0 or reverse.
The remaining two coils are driven with the NOT of the first two signals.