Accelstepper encoder nema 17 1:1

[Edgars Bellins]

Hello

I would like make rotary encoder and nema 17 1:1, but have problem when encoder rotate fast lose increments. And motor not rotate with the same speed when turn slowly/normal then works good.

Encoder increments per revolution 2000

Stepper Nema 17 1.8 degrees

Sorry for my english :)

Sketch which i use:

////////////////////////////////////////
	//Arduino + Optical Encoder + Stepper //
	////////////////////////////////////////
	// Adi Soffer 2013 //
	// for more info visit //
	// http://adisoffer.tumblr.com //
	#include <AccelStepper.h>
	//encoder/motor/driver setup
	int easyDriverMicroSteps = 4; //2,4,8
	int rotaryEncoderSteps = 75; //setps per rev on your encoder
	int motorStepsPerRev = 200; //steps per rev on the motor
	int MinPulseWidth = 50; //too low and the motor will stall, too high and it will slow it down
	int easyDriverDirPin = 16;
	int easyDriverStepPin = 15;
	int enablePin = 17;
	//Sleep Function - to diable ED when not active
	long previousMillis = 0;
	int sleepTimer = 5000;
	int val;
	int encoder0PinA = 3;
	int encoder0PinB = 4;
	int encoderValue = 0;
	long lastencoderValue = 0;
	int encoder0PinALast = LOW;
	int n = LOW;
	AccelStepper stepper(1, easyDriverStepPin, easyDriverDirPin);
	void setup() {
	pinMode (encoder0PinA,INPUT);
	pinMode (encoder0PinB,INPUT);
	pinMode(enablePin, OUTPUT);
	stepper.setMinPulseWidth(MinPulseWidth); //may need to play with this, but I think this is good.
	stepper.setMaxSpeed(50000);
	stepper.setAcceleration(1000000000); //try 100, or 1000 and see if it works
	stepper.setSpeed(50000); //play with this to see if it makes a diff (1 to 1000)
	}
	void loop() {
	int stepsPerRotaryStep = (motorStepsPerRev * easyDriverMicroSteps) / rotaryEncoderSteps;
	stepper.moveTo(encoderValue * stepsPerRotaryStep);
	stepper.run();
	if(encoderValue != lastencoderValue)
	{
	lastencoderValue = encoderValue;
	digitalWrite (enablePin, LOW);
	previousMillis = millis();
	}
	else
	{
	//Stepper sleep after 5sec of no data
	unsigned long currentMillis = millis ();
	if (currentMillis - previousMillis>sleepTimer)
	digitalWrite (enablePin, HIGH);
	}
	n = digitalRead(encoder0PinA);
	if ((encoder0PinALast == LOW) && (n == HIGH)) {
	if (digitalRead(encoder0PinB) == LOW) {
	encoderValue--;
	}
	else {
	encoderValue++;
	}
	}
	encoder0PinALast = n;
	}

[Mike McCauley]

Hello,

Im not sure I understand your problem, but if you try to drive a stepper too
fast, it will lose steps. You can improve this by reducing the inertia of the
mechanical load, or by increasing the current sent to the stepper.

Cheers.

On Sunday, March 08, 2015 05:34:24 PM Edgars Bellins wrote:
> Hello
> I would like make rotary encoder and nema 17 1:1, but have problem when
> encoder rotate fast lose increments. And motor not rotate with the same
> speed when turn slowly/normal then works good.
> Encoder increments per revolution 2000
> Stepper Nema 17 1.8 degrees
> Sorry for my english :)
>
> Sketch which i use:

> > //////////////////////////////////////////Arduino + Optical Encoder +

> > Stepper ////////////////////////////////////////// // Adi Soffer 2013 ////

> > for more info visit //// http://adisoffer.tumblr.com // #include

> > <AccelStepper.h> //encoder/motor/driver setupint easyDriverMicroSteps =

> > 4; //2,4,8int rotaryEncoderSteps = 75; //setps per rev on your encoderint

> > motorStepsPerRev = 200; //steps per rev on the motor int MinPulseWidth =
> > 50; //too low and the motor will stall, too high and it will slow it down
> > int easyDriverDirPin = 16;int easyDriverStepPin = 15;int enablePin = 17;

> > //Sleep Function - to diable ED when not activelong previousMillis =

> > 0;int sleepTimer = 5000; int val; int encoder0PinA = 3;int encoder0PinB =
> > 4;int encoderValue = 0;long lastencoderValue = 0; int encoder0PinALast =
> > LOW;int n = LOW;AccelStepper stepper(1, easyDriverStepPin,
> > easyDriverDirPin); void setup() { pinMode (encoder0PinA,INPUT); pinMode
> > (encoder0PinB,INPUT); pinMode(enablePin, OUTPUT);
> > stepper.setMinPulseWidth(MinPulseWidth); //may need to play with this,
> > but I think this is good.
> > stepper.setMaxSpeed(50000); stepper.setAcceleration(1000000000); //try
> > 100, or 1000 and see if it works stepper.setSpeed(50000); //play with
> > this to see if it makes a diff (1 to 1000)} void loop() { int
> > stepsPerRotaryStep = (motorStepsPerRev * easyDriverMicroSteps) /
> > rotaryEncoderSteps; stepper.moveTo(encoderValue * stepsPerRotaryStep);
> > stepper.run(); if(encoderValue != lastencoderValue) { lastencoderValue =
> > encoderValue; digitalWrite (enablePin, LOW); previousMillis = millis(); }
> > else { //Stepper sleep after 5sec of no data unsigned long currentMillis
> > = millis (); if (currentMillis - previousMillis>sleepTimer) digitalWrite
> > (enablePin, HIGH); } n = digitalRead(encoder0PinA); if ((encoder0PinALast
> > == LOW) && (n == HIGH)) { if (digitalRead(encoder0PinB) == LOW) {
> > encoderValue--; } else { encoderValue++; } } encoder0PinALast = n;}

--
Mike McCauley VK4AMM mi...@airspayce.com
Airspayce Pty Ltd 9 Bulbul Place Currumbin Waters QLD 4223 Australia
http://www.airspayce.com
Phone +61 7 5598-7474

[gregor]

Hi,

i'm not sure i understand your problem correctly, but given this:

Encoder increments per revolution 2000

and the fact you use digialRead() to read the state of the encoder my guess is that - at higher speeds - digitalRead() is too slow to pick up the signal from the encoder correctly.
on an arduino uno, digitalRead() can be called 220x / millisecond at best: http://jeelabs.org/2010/01/06/pin-io-performance/
in your loop code you have 1 digitalWrite() and at least 1 digitalRead(), limiting your code to about 10.000 digitalRead() calls per second (not considering interrupts, the second digitalRead() and the rest of the code)
if this really is the source of the problem you should be able to fix it using one of 2 methods:

direct port reads are a lot faster than using digitalRead() (see link above), here's a library for that: https://code.google.com/p/digitalwritefast/
external encoders, like here: http://astro.neutral.org/arduino/arduino-telescope-control.shtml section "What is the hardware?".

[Edgars Bellins]

Try this but without changes

////////////////////////////////////////

//Arduino + Optical Encoder + Stepper //

////////////////////////////////////////

 

//      Adi Soffer  2013       //

//    for more info visit      //

// http://adisoffer.tumblr.com //

#include <AccelStepper.h>

#include <digitalWriteFast.h>

//encoder/motor/driver setup

int easyDriverMicroSteps = 16; //2,4,8

int rotaryEncoderSteps = 2000; //setps per rev on your encoder

int motorStepsPerRev = 200; //steps per rev on the motor

int easyDriverStepPin = 5;

int enablePin = 17;

//Sleep Function - to diable ED when not active

long previousMillis = 0;

int sleepTimer = 5000;

int val; 

int encoder0PinA = 2;

int encoder0PinB = 3;

int encoderValue = 0;

long lastencoderValue = 0;

int encoder0PinALast = LOW;

int n = LOW;

AccelStepper stepper(1, easyDriverStepPin);

void setup() { 

  pinMode (encoder0PinA,INPUT);

  pinMode (encoder0PinB,INPUT);

  pinMode(enablePin, OUTPUT);

  stepper.setMaxSpeed(200000);

  stepper.setAcceleration(1555555555); //try 100, or 1000 and see if it works

  stepper.setSpeed(200000); //play with this to see if it makes a diff (1 to 1000)

} 

void loop() { 

  int stepsPerRotaryStep = (motorStepsPerRev * easyDriverMicroSteps) / rotaryEncoderSteps;

  stepper.moveTo(encoderValue * stepsPerRotaryStep);

  stepper.run();

  if(encoderValue != lastencoderValue)

  {

    lastencoderValue = encoderValue;

    digitalWrite (enablePin, LOW);

    previousMillis = millis();

  } 

  else

  {

    //Stepper sleep after 5sec of no data

    unsigned long currentMillis = millis ();

    if (currentMillis - previousMillis>sleepTimer)

      digitalWrite (enablePin, HIGH); 

  }

  n = digitalReadFast(encoder0PinA);

  if ((encoder0PinALast == LOW) && (n == HIGH)) {

    if (digitalReadFast(encoder0PinB) == LOW) {

[gregor]

hi,
the speed you set is very high. 200000 steps / second, are you sure this is correct?
you do not need to call setSpeed() when you use run(), setSpeed() is for using runSpeed().
you can substitute digitalWrite() with digialWriteFast().

On Monday, March 9, 2015 at 9:19:45 PM UTC+1, Edgars Bellins wrote:

Try this but without changes

[gregor]

another thing i noticed: when you use the digitalWriteFast library the pin numbers must be known at compile time, or else it will fall back to the standard digitalRead() / digitalWrite() functions.
so, either define the pin numbers like this:

#define encoder0PinA 2

#define encoder0PinB 3

int encoderValue = 0;

 or write

n = digitalReadFast(2);

good luck

[Edgars Bellins]

Thanks for help, i have one more question i need when encoder after turn stop longer for 5sec stepper make 500steps it is possible? :) I write where is sleep timer stepper.move(500); but not make 500 steps but turns all time

[gregor]

yes, it is possible.
below is a simple example for a timeout, 5 seconds after the stepper has stopped (and the last stepper destination was set using the encoder) the stepper will move 500 steps.

not tested.

bool destination_encoder;
bool timeout_active;
long stop_time;

void loop() {
  int stepsPerRotaryStep = (motorStepsPerRev * easyDriverMicroSteps) / rotaryEncoderSteps;
  stepper.moveTo(encoderValue * stepsPerRotaryStep);

  bool moving = stepper.run();       //moving will be true when the stepper is moving towards a target.

  if(encoderValue != lastencoderValue)
  {
    lastencoderValue = encoderValue;
    digitalWrite (enablePin, LOW);
    previousMillis = millis();

    destination_encoder = true;    //destination set by encoder.
  }
  else

  {
    //Stepper sleep after 5sec of no data
    unsigned long currentMillis = millis ();
    if (currentMillis - previousMillis>sleepTimer)
      digitalWrite (enablePin, HIGH);
  }
  n = digitalReadFast(encoder0PinA);
  if ((encoder0PinALast == LOW) && (n == HIGH)) {
    if (digitalReadFast(encoder0PinB) == LOW) {
      encoderValue--;
    }
    else {
      encoderValue++;
    }
  }
  encoder0PinALast = n;

 
  if (moving) timeout_active = false;

  //memorize the time when the stepper has stopped moving.
  if (!moving && !timeout_active)
  {
    timeout_active = true;
    stop_time = millis();
  }

  //when the stepper has stopped, the timeout (in this case: 5000ms) has expired,
  //and the last destination was set by the encoder, set a new stepper target.
  if (timeout_active && (millis() - stop_time() >= sleepTimer) && destination_encoder)
  {   
    stepper.move(500); 
    destination_encoder = false;  //destination set by timeout code.
  } 
}

[Edgars Bellins]

Try this but show error 

Arduino: 1.6.1 (Windows 7), Board: "Arduino Uno"

arduino_varbuut_driiz.ino: In function 'void loop()':

arduino_varbuut_driiz.ino:62:5: error: 'destination_encoder' was not declared in this scope

arduino_varbuut_driiz.ino:85:15: error: 'timeout_active' was not declared in this scope

arduino_varbuut_driiz.ino:88:19: error: 'timeout_active' was not declared in this scope

arduino_varbuut_driiz.ino:91:5: error: 'stop_time' was not declared in this scope

arduino_varbuut_driiz.ino:96:7: error: 'timeout_active' was not declared in this scope

arduino_varbuut_driiz.ino:96:47: error: 'stop_time' was not declared in this scope

arduino_varbuut_driiz.ino:96:67: error: 'destination_encoder' was not declared in this scope

Error compiling.

  This report would have more information with

  "Show verbose output during compilation"

  enabled in File > Preferences.

 

Sketch:

////////////////////////////////////////

//Arduino + Optical Encoder + Stepper //

////////////////////////////////////////

 

//      Adi Soffer  2013       //

//    for more info visit      //

// http://adisoffer.tumblr.com //

#include <AccelStepper.h>

//encoder/motor/driver setup

int easyDriverMicroSteps = 16; //2,4,8

int rotaryEncoderSteps = 2800; //setps per rev on your encoder

int motorStepsPerRev = 200; //steps per rev on the motor

int easyDriverDirPin = 16;

int easyDriverStepPin = 5;

int enablePin = 9;

//Sleep Function - to diable ED when not active

long previousMillis = 0;

int sleepTimer = 5000;

int val; 

int encoder0PinA = 2;

int encoder0PinB = 3;

int encoderValue = 0;

long lastencoderValue = 0;

int encoder0PinALast = LOW;

int n = LOW;

AccelStepper stepper(1, easyDriverStepPin, easyDriverDirPin);

void setup() { 

  pinMode (encoder0PinA,INPUT);

  pinMode (encoder0PinB,INPUT);

  pinMode(enablePin, OUTPUT);

  stepper.setMaxSpeed(50000);

  stepper.setAcceleration(1000000000); //try 100, or 1000 and see if it works

bool destination_encoder;

bool timeout_active;

long stop_time;

}

void loop() { 

  int stepsPerRotaryStep = (motorStepsPerRev * easyDriverMicroSteps) / rotaryEncoderSteps;

  stepper.moveTo(encoderValue * stepsPerRotaryStep);

  bool moving = stepper.run();       //moving will be true when the stepper is moving towards a target.

  if(encoderValue != lastencoderValue)

  {

    lastencoderValue = encoderValue;

    digitalWrite (enablePin, LOW);

    previousMillis = millis();

    destination_encoder = true;    //destination set by encoder.

  } 

  else

  {

    //Stepper sleep after 5sec of no data

    unsigned long currentMillis = millis ();

    if (currentMillis - previousMillis>sleepTimer)

      digitalWrite (enablePin, HIGH); 

  }

  n = digitalRead(encoder0PinA);

  if ((encoder0PinALast == LOW) && (n == HIGH)) {

    if (digitalRead(encoder0PinB) == LOW) {

      encoderValue--;

    } 

    else {

      encoderValue++;

    }

  } 

  encoder0PinALast = n;

  

[gregor]

this compiles:

  if (timeout_active && (millis() - stop_time >= sleepTimer) && destination_encoder)

  {    
    stepper.move(500);  
    destination_encoder = false;  //destination set by timeout code.
  }  
}

the variables

bool destination_encoder;

bool timeout_active;

long stop_time;

need to be defined in global scope (not in the setup() function)
also there was a typo, the bold () are wong:

[Edgars Bellins]

No more error, but stepper not make steps after encoder stopping. I think timer switching on when encoder turns, because when i put timer 2000 stepper not turn 1:1 when put 15000 then turns ok. Thank you

////////////////////////////////////////

//Arduino + Optical Encoder + Stepper //

////////////////////////////////////////

 

//      Adi Soffer  2013       //

//    for more info visit      //

// http://adisoffer.tumblr.com //

#include <AccelStepper.h>

//encoder/motor/driver setup

int easyDriverMicroSteps = 16; //2,4,8

int rotaryEncoderSteps = 2800; //setps per rev on your encoder

int motorStepsPerRev = 200; //steps per rev on the motor

int easyDriverDirPin = 16;

int easyDriverStepPin = 5;

int enablePin = 12;

//Sleep Function - to diable ED when not active

long previousMillis = 0;

int sleepTimer = 2000;

int val; 

int encoder0PinA = 2;

int encoder0PinB = 3;

int encoderValue = 0;

long lastencoderValue = 0;

bool destination_encoder;

bool timeout_active;

long stop_time;

int encoder0PinALast = LOW;

int n = LOW;

AccelStepper stepper(1, easyDriverStepPin, easyDriverDirPin);

void setup() { 

  pinMode (encoder0PinA,INPUT);

  pinMode (encoder0PinB,INPUT);

  pinMode(enablePin, OUTPUT);

  stepper.setMaxSpeed(50000);

  stepper.setAcceleration(1000000000); //try 100, or 1000 and see if it works

}

void loop() { 

  int stepsPerRotaryStep = (motorStepsPerRev * easyDriverMicroSteps) / rotaryEncoderSteps;

  stepper.moveTo(encoderValue * stepsPerRotaryStep);

  bool moving = stepper.run();       //moving will be true when the stepper is moving towards a target.

  if(encoderValue != lastencoderValue)

  {

    lastencoderValue = encoderValue;

    digitalWrite (enablePin, LOW);

    previousMillis = millis();

    destination_encoder = true;    //destination set by encoder.

  } 

  else

  {

    //Stepper sleep after 5sec of no data

    unsigned long currentMillis = millis ();

    if (currentMillis - previousMillis>sleepTimer)

      digitalWrite (enablePin, HIGH); 

  }

  n = digitalRead(encoder0PinA);

  if ((encoder0PinALast == LOW) && (n == HIGH)) {

    if (digitalRead(encoder0PinB) == LOW) {

      encoderValue--;

    } 

    else {

      encoderValue++;

    }

  } 

  encoder0PinALast = n;

  

[gregor]

i think i see the problem.
 your code switches off the enable pin of you A4988 driver 2000 ms after the enoder has been changed the last time. my code does not switch the enable pin back on, but when you set a longer sleepTimer value (like 15000) my code has plenty of time to finish before your code switches off the enable pin.
i think this might work:

 if (timeout_active && (millis() - stop_time >= sleepTimer) && destination_encoder)
  {    
    stepper.move(500);  
    destination_encoder = false;  //destination set by timeout code.

    previousMillis = millis();    
    digitalWrite(enablePin, LOW);
  }

[Edgars Bellins]

I think with enable pin is ok, because stepper turn when turn encoder only not move after i stop turn encoder. 

[Edgars Bellins]

Maybe need change tihs place 

if (timeout_active && (millis() - stop_time >= sleepTimer) && destination_encoder)

because i put sleep timer 5000 

turn encoder and after 5 sec when turn encoder stepper turns but slowly