Stepper Motor, No Acceleration

Hi All,

I have an oscillation motion operating on two optical endstops. I also have it wired to startup on with the touch of a button using an ezButton library.

The Endstops work. The Oscillation Works. The Startup button works. However, I noticed that I upon startup, I don’t have acceleration. It just starts off at the set speed I designated. Why is that? I have set the acceleration, so I’m not sure what’s going on.

Any ideas? I’m still fairly new to coding so any help would be so much appreciated.


#include <AccelStepper.h> //accelstepper library
#include <ezButton.h>


// constants won't change. They're used here to set pin numbers:
const byte limitSwitch_1 = 2; //pin for the microswitch
const byte limitSwitch_2 = 3; //pin for the microswitch
int smDirectionPin = 9; //Direction pin
int smStepPin = 8; //Stepper pin

// variables will change:
int switch1State = 0;         // variable for reading the Switch 1 status
int switch2State = 0;         // variable for reading the Switch 2 status
boolean ForwardState = 0;     // variable for reading the micro-switch status
boolean BackwardState = 0;    // variable for reading the microswitch status

// create ezButton object that attach to pin 7;
ezButton button(7);
int loopState = LOOP_STATE_STOPPED;

//direction Digital 9 (CCW), pulses Digital 8 (CLK)
AccelStepper stepper(1, 9, 8);

void setup()
  //Limit Switches
  pinMode(limitSwitch_1, INPUT_PULLUP); // internal pullup resistor (debouncing)
  pinMode(limitSwitch_2, INPUT_PULLUP); // internal pullup resistor (debouncing)

  //Stepper parameters
  //setting up some default values for maximum speed and maximum acceleration
  stepper.setMaxSpeed(5000); //SPEED = Steps / second

  // set debounce time to 50 milliseconds

void SlideForward()

void SlideBackward()

void loop() {
  button.loop(); // MUST call the loop() function first

  if (button.isPressed()) {
    if (loopState == LOOP_STATE_STOPPED)
      loopState = LOOP_STATE_STARTED;
    else // if(loopState == LOOP_STATE_STARTED)
      loopState = LOOP_STATE_STOPPED;

  if (loopState == LOOP_STATE_STARTED) {
    // read the state of the switches value;
    ForwardState = digitalRead(limitSwitch_1);
    BackwardState = digitalRead(limitSwitch_2);

    //step the motor (this will step the motor by 1 step at each loop indefinitely)

    // check which pin 2 or 3 is HIGH:
    if (ForwardState == HIGH && BackwardState == LOW) {

    if (BackwardState == HIGH && ForwardState == LOW) {

From the AccelStepper class reference.

Poll the motor and step it if a step is due, implementing a constant speed as set by the most recent call to setSpeed().

Note constant speed.

The run() function does acceleration.

Poll the motor and step it if a step is due, implementing accelerations and decelerations to achieve the target position.

Use move() or moveTo() to start motion, not runSpeed. To stop use stop().

move(0x7FFFFFFFL) can be used to move indefinitely (for most practical purposes,
even at 4000 steps/second that's 6 days.

runSpeed() doesn't do acceleration - bit annoying, but for standard position control you'd
only be using move() and moveTo() and driving everything with run().