Stepper Motor, No Acceleration

Using Arduino Motors, Mechanics, Power and CNC
#1

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.

Thanks!

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

#define LOOP_STATE_STOPPED 0
#define LOOP_STATE_STARTED 1

// 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
  stepper.setSpeed(5000);
  stepper.setAcceleration(500);

  // set debounce time to 50 milliseconds
  button.setDebounceTime(50);
}

void SlideForward()
{
  stepper.setSpeed(500);
}

void SlideBackward()
{
  stepper.setSpeed(-500);
}

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)
    stepper.runSpeed();

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

    if (BackwardState == HIGH && ForwardState == LOW) {
      SlideBackward();
    }
  }
}
#2

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.
#3

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().

#4