How to describe speed of stepper motor in RPM

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1

hello,
how can i describe RPM of stepper motor if i have delay time and step angle?
this is my code

const int stepPin=3;
const int dirPin=4;

void setup() {
  pinMode(3,OUTPUT);
  pinMode(4,OUTPUT);
}
void loop() {
  digitalWrite(dirPin,HIGH);

  for(int x=0; x < 2000000; x++) {
digitalWrite(stepPin,HIGH);
delayMicroseconds(500);
digitalWrite(stepPin,LOW);
delayMicroseconds(500);
  }
  delay(1000);

  digitalWrite(dirPin,LOW);

  for(int x = 0; x < 400; x++) {
    digitalWrite(stepPin,LOW);
    delayMicroseconds(500);
    digitalWrite(stepPin,LOW);
    delayMicroseconds(500);
  }
  delay(1000);

i want to describe 5 or 10 RPM how can i do this?
thank you

2

From that code and absence of technical data it's impossible tell.
Read the topic "How to get the best out of this forum".

3

Maths. Simple at that.

delay time is the reciprocal of frequency

delay time 10 ms -> frequency is 100 Hz. 100 steps per second

step angle is fraction of circle

step angle 10 degrees, 360 / 10 is 36 steps per revokution.

So 100 steps / rev divided by 36 is 2.77 revolutions per second

is 2.77 x 60 or 167 RPM.

Use your own constants which you must know or can deduce from the code.

HTH

Yes, @n_regev1 might well have stated the steps per unit of time as well as the step angle of the motor. So I just guessed the delay between steps and the angle stepped. As a for examl,e.

a7

4

delay time is 500 ms according the code and the step angle is 1.8 degree

5

No, the delay is not 500ms (milliseconds) it is 500microseconds.

(or twice that?)

6

No. The time for one complete step is 500 + 500 microseconds.

7

Thank you Railroader, I was editing my post when you corrected me.

8

how can i know the time for step?
if i know that the step angle is 1.8 degree i need to do 200 steps for one cycle.

9

Here's one thought:

500 + 500 is 1000. 1000 microseconds is 1 millisecond is 0.001 seconds.

Beyond that, it's simple mathematics.

Give it a try.

a7

10

@alto777 No problem with a master degree. Just didn't feel like rewarding the poor post of OP with a complete course covering all possible steppers.

1 Like
11

More like no problem after Year 8 or 9. :expressionless:

a7

12

Haha. I agree but all members wouldn't....

13

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