Problem controlling a Stepper motor with AccelStepper

Question

I have an Arduino connected to a stepper motor with an Easy Driver as follows:

I am controlling the position of the stepper motor using the Serial. This is my code:

#include <AccelStepper.h>
AccelStepper stepper(1, 9, 8);

void setup()
{  
  Serial.begin(9600);
  stepper.setMaxSpeed(10000);
  stepper.setAcceleration(5000);
}

void loop()
{
  char c;
  if(Serial.available())  
  {  
   int steps = Serial.parseInt();
   Serial.print(steps);
   stepper.moveTo(steps);

  }
  stepper.run();
}

The code works well but I'm facing a problem, when I set a high position value, it starts turning in the opposite direction, like if there was a limit on the steps. Does anyone know why it starts turning to the opposite direction?

I have tried to solve this problem by using:

if (stepper1.distanceToGo() == 0)        
         { 
            stepper1.setCurrentPosition(0);
         }  

so I can set lower values to the serial. But the problem goes back again when the value goes up to the power of 6 (like 1000000).

Any idea?

Thanks!

Answer 1

Ints on vanilla Arduinos are 16 bits, and signed, which means they hold values from -2^15 to +2^15-1, so of course you cannot assign 10^6 to one of them. Use unsigned long (4 bytes), or, better yet, specify the length explicitly by using uint32_t.