This script animates "Box" attached to an curve with MapPathParameter # It can be used for animation of indexing conveyor (start/stop)

attachment-animation-with-pauses.py

# This script animates "Box" attached to an curve with MapPathParameter
# It can be used for animation of indexing conveyor (start/stop)
import FreeCAD as App, FreeCADGui as Gui, Part, time
from PySide2 import QtGui,QtCore

class Animation(object):
    def __init__(self):
        App.Console.PrintMessage('Animation has started\n')
        App.ActiveDocument.recompute()

        self.timer = QtCore.QTimer()
        QtCore.QObject.connect(self.timer, QtCore.SIGNAL("timeout()"), self.my_update)
        self.step_time = 100 # step every 0.05s (50 ms)
        self.wait_time = 1000 # wait 1s on every stop step
        self.timer.start(self.step_time)
        self.val = 0 # start
        self.step = 10 # step value
        self.stop_step = 70 # pause evey 70, distance beetween "conveyor" stop position
        self.end = 2100 # end value, "conveyor" lenght

    def my_update(self):
        valf = 1.0 / self.end * self.val # MapPathParameter can vary from 0 to 1
        App.ActiveDocument.getObject('Box').MapPathParameter = valf #move the box on the path
        self.val = self.val + self.step
        App.ActiveDocument.recompute()
        if (self.val % self.stop_step):
            self.timer.start(self.step_time)
        else:
            self.timer.start(self.wait_time)
        if self.val > self.end:
            # self.timer.stop() #uncomment to stop animation after reaching end value
            self.val = 0.0

    def stop(self):
        self.timer.stop()
        App.Console.PrintMessage('Animation stopped\n')

animation = Animation()

#to stop type animation.stop()