Why isnt my code working?

Projects Programming
1

Im pretty new to arduino, and i wanted to write a code where i control a stepper to do a certain movement (different angles the stepper should drive to) depending on the position of my rotary encoder. Sadly i've runned into some problems pretty early. Getting a value on my serial monitor by turning the rotary encoder is no problem but as soon as i put (Motor.step(2048)) or something else related to the stepper into the loop i can't get a value from my rotary encoder anymore to let the stepper drive somewhere depending of that value the encoder gives me. I hope anyone can help.

#include <Stepper.h>

int Steps = 2048;
Stepper Motor(Steps, 10, 11, 12, 13);

#define outputA 2
#define outputB 3

int counter = 0;
int aState;
int aLastState;


void setup() {
  // put your setup code here, to run once:
  Motor.setSpeed(5);
  
  pinMode(outputA, INPUT_PULLUP);
  pinMode(outputB, INPUT_PULLUP);

  Serial.begin(9600);
  aLastState = digitalRead(outputA);

  for (int i = 2; i <10; i++) {
    pinMode(i, OUTPUT);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  aState = digitalRead(outputA);
  if(aState != aLastState) {
    if(digitalRead(outputB) != aState) {
      counter ++;
    } else {
      counter --;
    }
    Serial.print("Position: ");
    Serial.println(counter);
  }
  aLastState = aState;

  Motor.step(2048);
}

No matter how i put this code for the stepper into the loop, the encoder doesnt work anymore.

2

This is because you can not read your encoder fast enough. You should use a proper encoder Library that uses interrupts, This is a good one
http://www.pjrc.com/teensy/td_libs_Encoder.html

3

After setting Pin 2 a an INPUT_PULLUP you set it to OUTPUT

4

And then you do:-

Why?

5

Keep in mind that the step() method in the Stepper library is blocking. In other words it does not return until it completes the number of steps specified.

You have a couple of choices to minimize blocking:

  1. Only call the step() method with 1 step and control the speed yourself
  2. Use the AccelStepper library which is non-blocking.

You may still want to use an encoder library as @Grumpy_Mike suggested. In any case, the more you can avoid blocking the more responsive your sketch will be.

6

Updated my code to this now but still not working.

#include <AccelStepper.h>
#include <Encoder.h>

Encoder myEnc(12, 13);

AccelStepper stepper; 
void setup()
{  
    stepper.setMaxSpeed(200.0);
    stepper.setAcceleration(100.0);

    Serial.begin(9600);
    Serial.println("Basic Encoder Test:");
}

long oldPosition  = -999;

void loop()
{    
  long newPosition = myEnc.read();
  if (newPosition != oldPosition) {
    oldPosition = newPosition;
    Serial.println(newPosition);
  }
    
    stepper.runToNewPosition(0);
    stepper.runToNewPosition(2048);
    delay(5000);
}

All im getting from the serial monitor is "Basic Encoder Test:
0" right when i upload the programm to the arduino.

7

You actually made it worse!!!

delay(5000) blocks for 5 seconds. Why are you delaying? runToNewPosition() is also a blocking call!

Don't use delay()! In AccelStepper use the moveTo(), setSpeed(), and run() methods. Read the AccelStepper documentation. classAccelStepper

8

Are you using an UNO? If so I would not use pin 13 since the on-board LED is attached to that. Also I am assuming you are not using a driver stepper. If you are not and since you instantiated the stepper object with no parameters then your motor needs to be connected to pins 2, 3, 4, and 5.

For the encoder you need to make sure the pins you are using are usable for interrupts. For example, on an UNO only pins 2 and 3 are capable of interrupting.

9

Thanks everyone. Everything works as it should now and i learned what libraries are! :grinning:

10

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