StepperDriver.device.nut

class Stepper {
    pinArray = null;
    currentPosition = null;         // 0
    stepsPerFullRotation = null;    // 200
    pin = null;                     // id for pinArray
    delayTime = null;               // seconds
    
    constructor(_firstPin, _secondPin, _thirdPin, _fourthPin, _stepsPerFullRotation, _delayTime)
    {
        pinArray = [_firstPin, _secondPin, _thirdPin, _fourthPin];
        for (local i = 0; i < 4; i++)
        {
            pinArray[i].configure(DIGITAL_OUT);
            pinArray[i].write(0);
        }
        
        stepsPerFullRotation = _stepsPerFullRotation;
        delayTime = _delayTime;
        
        currentPosition = 0;
        pin = 0;
    }
    
    function StepForward()
    {
        currentPosition++;
        pin = (pin + 1);
        if (pin > 3) pin = 0;
        pinArray[pin].write(1);
        imp.sleep(delayTime);
        pinArray[pin].write(0);
    }
    
    function StepForwards(steps)
    {
        for (local i = 0; i < steps; i++)
            StepForward();
    }

    function StepBackward()
    {
        currentPosition--;
        pin = (pin - 1);
        if (pin < 0) pin = 3;
        pinArray[pin].write(1);
        imp.sleep(delayTime);
        pinArray[pin].write(0);
    }
    
    function StepBackwards(steps)
    {
        for (local i = 0; i < steps; i++) {
            StepBackward();
        }
    }
    
    function MoveTo(location)
    {
        local diff = currentPosition - location;
        
        if (diff > 0)
        {
            if (diff < (stepsPerFullRotation/2) StepBackwards(diff);
            else StepForwards(stepsPerFullRotation - diff);
        }
        else
        {
            if (diff > (stepsPerFullRotation/-2) StepForwards(math.abs(diff));
            else StepBackwards(stepsPerFullRotation + diff);
        }
        currentPosition = location;
        imp.sleep(1.0);
    }
    
    function Zero()
    {
        currentPosition = 0;
    }
}

stepper <- Stepper(hardware.pin2, hardware.pin7, hardware.pin5, hardware.pin8, 200, 0.005);