Motor Stepper Example

[cncmachineguy]

Hello all, after lots of posts with some other members here, and lots of digging on my own, I came to the conclusion for anything over 500mA drive capacity, it really is less expensive to go with a dedicated chip solution. This is when you figure in board space, manufacturing cost, ...

Just my 2 cents FWIW

[thenew]

please help me..we have a project using stepper motor..we are making simple linear robot..when the circuit is on it will automatically open the gripper then after a seconds it will close the grip then after a seconds the slider stepper will turn forward then after a seconds again the gripper will open again then close and back to its original position..

please give me sample code or correct my code because when i tried it the gripper will only vibrate:

clear
ti var byte
c var byte
z var byte
ti=100
trisb=0

gripper open(cw the gripper stepper):
for z=1 to 2
portb=128
pause ti
portb=64
pause ti
portb=32
pause ti
portb=16
pause ti
next z
goto delay

gripper open1(cw the gripper stepper):
for z=1 to 2
portb=128
pause ti
portb=64
pause ti
portb=32
pause ti
portb=16
pause ti
next z
goto delay3

close(reverse gripper stepper):
for z=1 to 2
portb=16
pause ti
portb=32
pause ti
portb=64
pause ti
portb=128
pause ti
next z
goto delay1

close1(reverse gripper stepper):
for z=1 to 3
portb=16
pause ti
portb=32
pause ti
portb=64
pause ti
portb=128
pause ti
next z
goto delay4

delay:
portb=0
pause 2000
goto close

delay1:
portb=0
pause 2000
goto loop
delay2:
portb=0
pause 2000
goto open1

delay3:
portb=0
pause 2000
goto close1

delay4:
portb=0
pause 2000
goto loop1
delay5:
portb=0
pause 2000
goto open

loop(cw the slider):
for c=0 to 11
portb=8
pause ti
portb=4
pause ti
portb=2
pause ti
portb=1
pause ti
next c
pause 2000
goto delay2

loop1(ccw the slider):
for c=0 to 11
portb=1
pause ti
portb=2
pause ti
portb=4
pause ti
portb=8
pause ti
next c
goto delay5
end

[luxornet]

If a stepper motor vibrate this is happen because the power supply is too low or the rotation speed (given by the code) is too high.

[thenew]

what is the correct speed or delay am i using in order to run it well?

it necessary to define the external oscillator in the program?like:

define osc 4

[cncmachineguy]

We really need to know more about the hardware. Are you using a uni-polor or bi-polor motor? How are you driving the motor? direct from the PIC (REALLY small motor) or with some kind of amplifier/driver? I don't think you are pulsing too fast, if you have a 200 step motor, you are asking it to move at 5 RPM (i think,)

Can you make the motor move by replacing the pic with 4 switches? this will simulate the pic to test the hardware. Although this still will not tell you about current needs.

[thenew]

i am using unipolar stepper motor...i connect the pic to uln2803...then connect to the stepper motor...

in your own experience..what time delay usually used in order the stepper to operate properly?

[cncmachineguy]

delay time all depends on how fast you need it to move.

Please do some simple troubleshooting for us. Replace the motor with LED's. then you will be able to see if all 4 lines are stepping. Vibrating can also come from a missed step or 2. Also could you please apply 5V to the input of the ULN, 1 at a time and see if the motor moves?

This problem really needs to be isolated to hardware, software, or both. At first glance, it seems like your program should work. I don't know if you will get your desired function, but the motor should move.