Stepper motor with button press

Projects Programming
1

This is my first time owning an Arduino, I have a stepper motor 28BYJ-48 with ULN2003 driver. I am trying to hook up a button press that will rotate it one full rotation clockwise and stop, and repeat one rotation every button press, but I am having difficulty writing this code as this is the first time I’ve done anything like this before. I’ve spent days watching tutorials and reading websites but can’t figure it out. I am stumped. Can anyone tell me what I am doing wrong? This is the current code I have written but it still does nothing when I upload it to the Arduino.

#include <Stepper.h>

// Define constants for the stepper motor
const int stepsPerRevolution = 2048;
const int stepsPerDegree = stepsPerRevolution / 360;

// Define pins for the ULN2003 driver
const int in1Pin = 8;
const int in2Pin = 9;
const int in3Pin = 10;
const int in4Pin = 11;

// Define pin for the button
const int buttonPin = 2;

// Create a new instance of the Stepper class
Stepper motor(stepsPerRevolution, in1Pin, in2Pin, in3Pin, in4Pin);

void setup() {
  // Set the motor speed (RPM)
  motor.setSpeed(10);

  // Set the button pin as input
  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
  // Wait for the button to be pressed
  while (digitalRead(buttonPin) == HIGH) {
    // Do nothing
  }

  // Rotate the motor 360 degrees (one revolution)
  motor.step(stepsPerRevolution);

  // Wait for the button to be released
  while (digitalRead(buttonPin) == LOW) {
    // Do nothing
  }
}
2

give the duck a go

1 Like
3

I have, as well as maker guides, I can find all kinds of code where you have to hold the button to have it rotate but nothing that triggers a full rotation and stop. I’ve tried pasting several strips of code together with no success

4
5

Hi @shrunkenned,

although the way you handle the button is not advisable (there is no "debouncing") you are lucky:

Your sketch works ... I assume that you might not have the correct value here

const int stepsPerRevolution = 2048;

What kind of stepper motor do you have? You may try this instead

const int stepsPerRevolution = 200;

Even if you leave away the second while() in loop() it should work, because the function

  motor.step(stepsPerRevolution);

blocks loop() until all steps have been performed. That is the reason why in your sketch debouncing is not necessary ...

This is your sketch but with a few changes and it works in Wokwi simulation:
(see here https://wokwi.com/projects/360659738759204865

Your modified sketch:

#include <Stepper.h>

// Define constants for the stepper motor
// const int stepsPerRevolution = 2048;
const int stepsPerRevolution = 200;
//const int stepsPerDegree = stepsPerRevolution / 360;

// Define pins for the ULN2003 driver
const int in1Pin = 8;
const int in2Pin = 9;
const int in3Pin = 10;
const int in4Pin = 11;

// Define pin for the button
const int buttonPin = 2;

// Create a new instance of the Stepper class
Stepper motor(stepsPerRevolution, in1Pin, in2Pin, in3Pin, in4Pin);

void setup() {
  Serial.begin(115200);
  // Set the motor speed (RPM)
  motor.setSpeed(50);

  // Set the button pin as input
  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
  // Wait for the button to be pressed
  while (digitalRead(buttonPin) == HIGH) {
    // Do nothing
  }
  Serial.println("Start Rotation");
  // Rotate the motor 360 degrees (one revolution)
  motor.step(stepsPerRevolution);
  Serial.println("Stop Rotation");
}

ec2021

P.S.: If your sketch does nothing after upload you should probably carefully check your wiring ...!!!

2 Likes
6

Thank you so much for the reply, very helpful! Will try this when I get home! :slightly_smiling_face:

7

Try:
Stepper motor(stepsPerRevolution, in1Pin, in3Pin, in2Pin, in4Pin);

1 Like
8

If you have not used Wokwi simulation you might find it quite useful to learn coding ...

There are plenty of examples with a lot of different actuators and sensors.

Good luck!
ec2021

9

Your initial steps per revolution was correct. A BYJ stepper has 2048 steps per revolution not 200.

10

That was it!!! For whatever reason that fixed it!! Thank you so much!

11

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