Stop the stepper motor immediately

[Portia-Lin]

Hello everyone. I would like to stop the stepper motor immediately after the limit switch has been triggered. If I call the stop() function, the stepper motor starts to decrease its speed depending on the given acceleration.
I need to stop the stepper motor now, so I use the code:
if (stepper.isRunning()) { stepper.moveTo(stepper.currentPosition()); }
It works. But there is a problem. After I set another position to move again, the stepper motor starts moving at maximum speed without using acceleration. This may cause the stepper motor in my device to jam. Are there any other solutions to this problem?
To set the movement speed, I use the setMaxSpeed() functions, and for the stepper motor movement: run().

[DougF42]

A temporary solution: Derive a subclass from AccelStepper,
(1) override the 'run' function, adding a test for a new 'estopTriggered' flag. IF the flag is not set, then call AccelStepper::run().
(2) create new fucntion estop() that sets this flag, AND sets _stepInterval to 0.
(3) Create new function reset_estop() that clears the flag to restore normal operations.

[lightzero]

create new fucntion estop()
void AccelStepper::eStop() { _speed=0.0; _targetPos=_currentPos; }

[DougF42]

@lightzero - I like your approach - it is much cleaner than my work-around. The estop() function will need one minor addition - also set _stepInterval=0. This will cause runspeed() to return false immediately, (properly indicating no motion) instead of doing another step (if the step interval has elapsed).

Resulting function:
void AccelStepper::eStop() { _speed=0.0; _targetPos=_currentPos; _stepInterval=0 }

[lightzero]

if set _stepInterval=0；the stepper motor starts moving at maximum speed without using acceleration.