One accelStepper drives all 4 motors from a CNC v3 stepper shield

Projects General Guidance
1

This is my first post on this forum so please be gentle, I am new to the dark arts of Arduino.
I have encountered this issue and it is driving me mad I have replicated it on an Uno and a Mega 2560, two different CNC v3 Clones and two sets of drivers (A4988 and DRV 8825) and I have removed and reinstalled the accesStepper library.
I have simplified the code as much as possible and just cannot see what the cause is.
When I run this code all 4 motors run, when I use setSpeed(1000) the X motor runs clockwise and all the others run anti-clockwise. When I use SetSpeed(-1000) everything goes anti-clockwise.

#include <Arduino.h>
#include <AccelStepper.h>

const byte PIN_X_STEP = 2;
const byte PIN_X_DIR = 5;
const byte PIN_X_LIMIT = 9;

const byte PIN_Y_STEP = 3;
const byte PIN_Y_DIR = 6;
const byte PIN_Y_LIMIT = 10;

const byte PIN_Z_STEP = 4;
const byte PIN_Z_DIR = 7;
const byte PIN_Z_LIMIT= 11;

const byte PIN_SPINDLE_EN = 12;
const byte PIN_SPINDLE_DIR = 13;
const byte PIN_COOL_EN = A3;

const byte PIN_ABORT = A0;
const byte PIN_HOLD = A1;
const byte PIN_RESUME = A2;

AccelStepper _stepper;

void setup() 
{
  pinMode(PIN_X_LIMIT,  INPUT_PULLUP);
  pinMode(PIN_Y_LIMIT,  INPUT_PULLUP);
  pinMode(PIN_Z_LIMIT,  INPUT_PULLUP);

  pinMode(PIN_SPINDLE_EN,  INPUT_PULLUP);
  pinMode(PIN_SPINDLE_DIR,  INPUT_PULLUP);
  pinMode(PIN_COOL_EN,  INPUT_PULLUP);

  pinMode(PIN_ABORT,  INPUT_PULLUP);
  pinMode(PIN_HOLD,  INPUT_PULLUP);
  pinMode(PIN_RESUME,  INPUT_PULLUP);

  pinMode(PIN_Y_STEP,  OUTPUT);
  pinMode(PIN_Y_DIR,  OUTPUT);

  pinMode(PIN_Z_STEP,  OUTPUT);
  pinMode(PIN_Z_DIR,  OUTPUT);

  digitalWrite(PIN_Y_STEP,0);
  digitalWrite(PIN_Y_DIR,0);

  digitalWrite(PIN_Z_STEP,0);
  digitalWrite(PIN_Z_DIR,0);

  AccelStepper _stepper(AccelStepper::DRIVER,PIN_X_STEP,PIN_X_DIR); 
}

void loop() 
{
  _stepper.setMaxSpeed(1000);
  _stepper.setSpeed(1000);
  _stepper.runSpeed();
}

Any help would be gratefully received.

2

Instead of this:

AccelStepper _stepper;

and this inside setup():

AccelStepper _stepper(AccelStepper::DRIVER, PIN_X_STEP, PIN_X_DIR);

try this once, outside of setup():

AccelStepper _stepper(AccelStepper::DRIVER, PIN_X_STEP, PIN_X_DIR);

There is a good chance that the line inside setup() creates only a local _stepper object, while loop() still uses the global one.

3

Spot on, the declaration in setup() was a duplicate of the previously declared global declaration which would have used default parameters. Many thanks.