Is it possible to control the speed of a stepper motor with an a4988 driver dynamically? I would like to realize a control system on an arduino, using speed and not position control.
Thanks in advance!

The > condition here can allow extra uSeconds of time to creep in to the stepping:

Since the condition to advance a step is >=, the result will be fewer steps than expected, in a given time frame.

This can be fixed by changing Stepper.cpp:201 to:

this->last_step_time += this->step_delay;

Argument for the existing code: that if the processor gets bogged down, the motors will step slower, and guarantee step counts. But, everything slows down.

Argument for updating the code: start to finish timing stays correct, but as the processor bogs down, it can lose steps at higher speeds.

Thank you for your attention to this detail.
Gerald Lafreniere

From @cmaglie on November 15, 2012 18:19

This is Issue 144 moved from a Google Code project.
Added by 2009-11-19T00:38:14.000Z by [email protected].
Please review that bug for more context and additional comments, but update this bug.

Original labels: Type-Enhancement, Priority-Medium

Original description

If the stepper doesn't complete a full resolution or goes for long periods of
time between steps or steps over a long period of time, it gets really hot
due to a bug in the stepper code. It leaves coils enegized. I have added a
motorOff() function that shuts off all power so that it will not become too
hot. Future development could be to insert a timer since we know the speed
and step degree and shut it off that way.

Copied from original issue: arduino/Arduino#144

Hey there!

I am currently using a WEMOS D1 mini together with a 4-Pin stepper motor.
It works correctly but after turning it, the esp runs through a software reset.

The Exception Decoder says the following:

0x402016a4: Stepper::stepMotor(int) at D:\Arduino\libraries\Stepper\src\Stepper.cpp line 356
0x402016df: Stepper::step(int) at D:\Arduino\libraries\Stepper\src\Stepper.cpp line 198

My code looks like this:

#include <NTPClient.h>
#include <Stepper.h>
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

// wifi settings
const char *ssid     = "Martin Router King";
const char *password = "<secret password here>";

// ntp settings
const long utcOffsetInSeconds = 3600;

char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

// Define NTP Client to get time
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "pool.ntp.org", utcOffsetInSeconds);

// stepper settings
Stepper Motor(2048, D1, D3, D2, D4);

void setup(){
  Serial.begin(115200);

  // wifi
  WiFi.begin(ssid, password);
  while ( WiFi.status() != WL_CONNECTED ) {
    delay ( 500 );
    Serial.print ( "." );
  }
  Serial.println("Connected!");

  // ntp
  timeClient.begin();

  // stepper
  Motor.setSpeed(10);
}

void loop() {
  timeClient.update();

  int currentHour = timeClient.getHours();

  if(currentHour % 12 == 0 && timeClient.getMinutes() == 6 && timeClient.getSeconds() == 0){
    Serial.println("Liftoff!");
    Motor.step(2048);
  }
  delay(1000);
}

The stepper motor is connected as follows:
IN1 -> D4
IN2 -> D3
IN3 -> D2
IN4 -> D1

As I said, it works and rotates but after its done my esp resets :/

Also I couldn't find any issue in the Stepper.cpp/Stepper.h (for my low experience level with C++).

EDIT: I tried using only the stepper motor without any NTP or anything else, it keeps resetting.

Moved from arduino/Arduino#3300 by @cxrodgers

I was having an intermittent issue where my arduino would occasionally lock up while stepping a stepper. It turned out that it was because I had neglected to call setSpeed explicitly. I had thought that it defaulted to some reasonable value, but upon examining the code, I see that it does not, meaning that step_delay will be whatever random value resides in that memory location.
https://github.com/arduino/Arduino/blob/master/libraries/Stepper/src/Stepper.cpp

Here was my forum posting on this topic.
http://forum.arduino.cc/index.php?topic=327132.0

I believe that the memory is typically set to zero, but when using dynamic memory allocation (for instance: stepper = new Stepper(...), there is no guarantee that this memory location will start at zero. Regardless, it seems dangerous to rely on the memory containing any particular value without being initialized.

I think step_delay should be initialized to zero in the constructor. Alternatively, I think it should be documented that a call to setSpeed is required before calling step.

Hello, when using multiple stepper motors they don't work at the same time they work one by one, due to while loop used in the code.

#include <Stepper.h>

const int spr = 200;  // change this to fit the number of steps per revolution
const int rmp = 100;
// for your motor

// initialize the stepper library on pins 8 through 11:
Stepper sm1(spr, 52, 50, 48, 46);
Stepper sm2(spr, 44, 42, 40, 38);
Stepper sm3(spr, 36, 34, 32, 30);
Stepper sm4(spr, 28, 26, 24, 22);




void setup() {
  // set the speed at 60 rpm:
  sm1.setSpeed(rmp);
  sm2.setSpeed(rmp);
  sm3.setSpeed(rmp);
  sm4.setSpeed(rmp);
  Serial.begin(9600);

  //  myStepper.step(stepsPerRevolution);
}

void loop() {
  // step one revolution  in one direction:
  Serial.println("clockwise");
  sm1.step(spr);
  sm2.step(spr);
  sm3.step(spr);
  sm4.step(spr);

}

when m1 finished its first loop then m2 starts and it goes on.

Please change the while loop with some async loop which will allow other stepper motors to start simultaneously.

Hello.
My Arduino Uno board cannot handle steps_to_move bigger than 32767 which is the maximum of 16bits integer.
This was simply solved by modifying the int in below two lines to long.
I would like to modify the parts below so that we can use a wider range of step numbers without changing the board.
Is there any reason that we have to use int datatype instead of long datatype?

Stepper/src/Stepper.cpp

Line 184 in 9189fa7

void Stepper::step(int steps_to_move)

Stepper/src/Stepper.cpp

Line 186 in 9189fa7

int steps_left = abs(steps_to_move); // how many steps to take

Per

and

Some modified H-bridge drivers and high-end configurable stepper drivers can use the 2-wire C0/C1 A/B Quadrature output from this constructor:

The TI L293x datasheet (pg 9) shows this circuit for how to wire it up with some inverters to use two signals to drive 2-phase quadrature input:

and

From @cmaglie on November 15, 2012 18:19

This is Issue 139 moved from a Google Code project.
Added by 2009-11-05T07:28:01.000Z by [email protected].
Please review that bug for more context and additional comments, but update this bug.

Original labels: Type-Enhancement, Priority-Medium

Original description

Using a half-step-library would double the precision of the stepper.

Attached you'll find my proposal for the changed Stepper library. I kept
the changes to a minimum.
It contains a new (added) constructor, a private boolean which indicates
whether or not to use the half-step system. The Stepper::step function was
changed to allow 2, 4, or 8 steps and the Stepper::stepMotor was changed
to send the 8 different signals to the 4 wires.

Users who created sketches using the previous lib can change to this new
library without compatibility problems.

Copied from original issue: arduino/Arduino#139

Hi!
It's nothing serious but I got a little distracted in my work rechecking how micro() worked because of it.

So just to let you know that in line 105 in "Stepper.h", the comment says "// delay between steps, in ms, based on speed".
"ms" is short for millisecond, the correct abbreviation for microsecond is "µs" or for easier typing "us".

Reference:
https://simple.wikipedia.org/wiki/Second

Thank you for your time!

issue #1

Vv

Hi, I use this library and I would like to know if I can make a forced stop of the engine.