How to increase motor speed?

grbeltran

Using the····· Stepper.java and stepperTest.java, listed very commonly in the forum, how do I increase the speed
of the motor?

I have decreased the delay in between each step to 1 or EVEN O ..
Example

public class stepperTest {
· public static void main() {
··· boolean x1 = true;
··· Stepper motor = new Stepper(CPU.pin4, CPU.pin5, CPU.pin6, CPU.pin7);
··· while(x1 = true) {
····· motor.stepFFwd(48, 0);·················· // one rev clockwise
····· CPU.delay(5000);························· // wait 1/2 second
····· motor.stepFRev(48, 0);·················· // one rev counter clockwise
····· CPU.delay(5000);························· // wait 1/2 second
··· }
· }
}

and it increases the speed but I need to increase the frequency somehow... or be able to change the delay(in between steps) to us...?
can anybody please help?

Thanks,

Gabe

Peter Verkaik

Please post URL to thread where stepper.java is attached,
or attach stepper.java. So we have not to search for it.

regards peter

grbeltran

Okay, I am sorry.· The stepper files are in this attachment.· Any help is greatly appreciated!


Thanks,
Gabe

Peter Verkaik

I found the product the files relate to.
http://www.parallax.com/detail.asp?product_id=27964

public class stepperTest {
· public static void main() {
··· boolean x1 = true;
··· Stepper motor = new Stepper(CPU.pin4, CPU.pin5, CPU.pin6, CPU.pin7);
··· while (x1) {
····· motor.stepFFwd(48, 15);·················· // one rev clockwise
····· CPU.delay(5000);························· // wait 1/2 second
····· motor.stepFRev(48, 15);·················· // one rev counter clockwise
····· CPU.delay(5000);························· // wait 1/2 second
··· }
· }
}

You could try lowering the CPU.delay(5000)
so the stepper motors get updated more
frequently.

regards peter

grbeltran

I believe the CPU.delay()· is the delay between stepping intervals,

Ex
step··step· step ·step ·step·<

---

(CPU.delay)·

---

> step· step ·step· step· step<

---

(CPU.delay)

---

> step etc.

right?

but what will·let me

stepstepstepstepstepstepstep· faster..

Thanks

Gabe·······

Peter Verkaik

Here are the methods in Stepper.java

· /**
·· * Sets up phase inputs for step index
·· */
· private void setFullStep(int theStep) {

···· switch (theStep) {

······ case 0:
········ CPU.writePin(ph1Pin, true);
········ CPU.writePin(ph2Pin, true);
········ CPU.writePin(ph3Pin, false);
········ CPU.writePin(ph4Pin, false);
········ break;

······ case 1:
········ CPU.writePin(ph1Pin, false);
········ CPU.writePin(ph2Pin, true);
········ CPU.writePin(ph3Pin, true);
········ CPU.writePin(ph4Pin, false);
········ break;

······ case 2:
········ CPU.writePin(ph1Pin, false);
········ CPU.writePin(ph2Pin, false);
········ CPU.writePin(ph3Pin, true);
········ CPU.writePin(ph4Pin, true);
········ break;

······ case 3:
········ CPU.writePin(ph1Pin, true);
········ CPU.writePin(ph2Pin, false);
········ CPU.writePin(ph3Pin, false);
········ CPU.writePin(ph4Pin, true);
········ break;
···· }
· }


· /**
·· * Step forward clockwise
·· *
·· * @param steps Number of CW steps
·· * @param msDelay delay between steps in milliseconds
·· */
· public void stepFFwd(int steps, int msDelay) {

··· while (steps-- > 0) {
····· stpIdx = (stpIdx + 1) % 4;
····· setFullStep(stpIdx);
····· CPU.delay(msDelay * 10);

··· }
· }


· /**
·· * Step forward counter-clockwise
·· *
·· * @param steps Number of CCW steps
·· * @param msDelay delay between steps in milliseconds
·· */
· public void stepFRev(int steps, int msDelay) {

··· while (steps-- > 0) {
····· stpIdx = (stpIdx + 3) % 4;
····· setFullStep(stpIdx);
····· CPU.delay(msDelay * 10);
··· }
· }
}

The minimal delay between steps is when using msDelay=0,
the delay is then determined by the loop
while (steps-->0)
in which setFullStep() is called.
setFullStep() itself contains 4 writePin() statements.

To minimize that delay you need to rewrite it,
instead of 4 CPU.writePin() you use 1 CPU.writePort()

Another option to minimalize the delay, is by defining stpIdx global,
so you don't need to pass it as a parameter each time.

regards peter

grbeltran

I see... okay, well my situation is slightly different because I already have a driver and a different stepper motor...

In other words all I need are two pins, step and direction.·· Simple i guess. but

does that

switch (theStep) {

······ case 0:
········ CPU.writePin(ph1Pin, true);
········ CPU.writePin(ph2Pin, true);
········ CPU.writePin(ph3Pin, false);
········ CPU.writePin(ph4Pin, false);
········ break;

······ case 1:
········ CPU.writePin(ph1Pin, false);
········ CPU.writePin(ph2Pin, true);
········ CPU.writePin(ph3Pin, true);
········ CPU.writePin(ph4Pin, false);
········ break;

etc...

even matter anymore, or what exactly is is for. Do I need it?



Thanks,



gabe

Peter Verkaik

Read this document,
http://www.parallax.com/dl/docs/prod/motors/Stepper_Motor_27964.pdf

You'll see the patterns are encoded in setFullStep.

If you have a different stepper motor, check the
datasheet on what patterns can be used.

regards peter