Help Understanding how to turn my motor off

Using Arduino Project Guidance
1

Hi everyone, I am building a prototype for an invention and I am very new to Arduino but it is what I needed to make my project work. I have had a little help to get this far so thank you all. However, I am not sure how to execute the last step in my sketch to make my motor turn off after 40 counterclockwise revs? When the motor switches from CW to CCW, does it keep counting revs up or does it then countdown? This is my issue, I am not sure what I need to write to get it to stop after 40 CCW revs. Can someone give me some guidance please? Thanks again.

const int stepPin = 5;
const int dirPin = 3;
const long stepsPerRevolution = 1375;
const int buttonPin = 4;
int buttonState = 0;
long Distance = 0;
void setup()
{
  // Declare pins as Outputs
  pinMode(stepPin, OUTPUT);
  pinMode(dirPin, OUTPUT);
  pinMode(buttonPin, INPUT);

}
void loop()
{
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  if (buttonState == HIGH) {

    // Set motor direction clockwise
    digitalWrite(dirPin, LOW);

    // Spin motor slowly
    for (int x = 0; x < stepsPerRevolution; x++)
    {
      digitalWrite(stepPin, HIGH);
      delayMicroseconds(500);
      digitalWrite(stepPin, LOW);
      delayMicroseconds(500);
      Distance = Distance + 1;
    }
  } else {
    // turn motor off:
    digitalWrite(stepPin, LOW);
    if (Distance == 55000L) {
      // Set motor direction counterclockwise
      digitalWrite(dirPin, HIGH);

      // Spin motor slowly
      for (int x = 0; x < stepsPerRevolution; x++)
      {
        digitalWrite(stepPin, HIGH);
        delayMicroseconds(500);
        digitalWrite(stepPin, LOW);
        delayMicroseconds(500);

      }
    } else {
      // turn motor off:
      digitalWrite(stepPin, LOW);

    }
  }
}
2

One way to do it would be to put the for loop that does one CCW rotation inside another for loop that does forty iterations.

When that's done, set Distance to zero so it doesn't run again.

3

Ok. Thank you. Would you please show me how? I am very new at this and trying to understand. Thank you.

Richard Potter

4 
if (Distance == 55000L)
{
  // Set motor direction counterclockwise
  digitalWrite(dirPin, HIGH);
  // Spin motor slowly
  for (int i = 0; i < 40; i++)
  {
    for (int x = 0; x < stepsPerRevolution; x++)
    {
      digitalWrite(stepPin, HIGH);
      delayMicroseconds(500);
      digitalWrite(stepPin, LOW);
      delayMicroseconds(500);
    }
  }
  Distance=0;
}```
Not tested, not even compiled
5

You are counting steps here:
Distance = Distance + 1;

When going in the other direction it is entirely up to you if you count up or count down. It's all just counting.

The AccelStepper library will keep track of your position by doing the counting for you. It will count up in one direction and down in the other. It also takes care of ramping the speed up and down to keep the stepper from missing steps by trying to change speed too quickly.

6

WOW! OK, Thank you, I did not know that.

7

WOW!! That works. Don't want to be a pain but could you explain what this line actually means??

for (int i = 0; i < 40; i++)

8

It means "Repeat this statement 40 times:". In this case, and many others, the 'statement' is a block of statements surrounded by '{' and '}'.

9

Thank you all very much, I am learning a lot by doing this.

10

More specifically, "for (A; B; C) statement;" means:

  {
    A;
    while (B)
    {
      statement;
      C;
    }
  }
11

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