help req. for driving stepper motor with 8051.....

[sarang2502]

Hello frnds,

im stuck; plz help...
im having a unipolar stepper with 6 terminals (2 COMM), 12v, 1A Supply...
i hav written assembly code:

Code:

org 0H

stepper equ P1

main:
        mov stepper, #08H
        acall delay
        mov stepper, #04H
        acall delay
        mov stepper, #02H
        acall delay
        mov stepper, #01H
        acall delay
        sjmp main
delay:
        mov r7,#2
wait2:
        mov r6,#0ccH
wait1:
        mov r5,#0ffH
wait:
        djnz r5,wait
        djnz r6,wait1
        djnz r7,wait2
        ret
        end
 

When motor is running it goes fwd for some time then suddenly goes backwd...
i have used this step sequence bcoz dis motor runs continous when one by one pulse is given to four terminals...

I am using driver IC L293D, problem is that; the step angle of motor is 5.3'...
i dont know how to use step angle for giving proper pulses...

im working on project of a robo car with two stepper motors interfaced with 8051..
it can move in all directions... if any suggestions, plz tell...

thnx in advance...

[shadowpucci]

hi! i´m new on this forum but i can help you

excuse-me because i´m not a natural english talker (i´m from argentina, we talk in spannish here!) but i find an explanation for your problem

1º you are using a strange sequence... if you connect directly the mottor (with his respective drive) the sequence than you have to use is 1-3-2-4 (0x01, 0x04, 0x02, 0x08 (hexadecimal notation on C)) so if the mottor runs, you´re being lucky!

2º you are usin a sequence that has good speed but low torque... so, the movement "unchains" magnetically and it starts to run backwards.. why don´t you use a half step sequence (1, 1+3, 3, 3+2, 2,2+4, 4, 4+1) it has very good torque and it runs sigilously... i´ve used this sequence on my informatica 2 final proyect and it runs well


there is a video of my proyect they runs great! and i connect 2 motors in parallel and they runs sinchronic

 <a href="http://www.youtube.com/v/n-EhPBCmabs&rel=0" target="_blank">http://www.youtube.com/v/n-EhPBCmabs&rel=0</a>


excuse my english!