10 V2 V1

`up_and_down.py`

I've included all the code from up_and_down.py below for your reference. Use this code as you answer the questions at the bottom of this page. Note that the backyard_flyer project code uses the term 'state' instead of 'phase' but they refer to the same concept.

import time
from enum import Enum
import numpy as np
from udacidrone import Drone
from udacidrone.connection import MavlinkConnection
from udacidrone.messaging import MsgID

class Phases(Enum):
    MANUAL = 0
    ARMING = 1
    TAKEOFF = 2
    LANDING = 3
    DISARMING = 4

class UpAndDownFlyer(Drone):

    def __init__(self, connection):
        super().__init__(connection)
        self.target_position = np.array([0.0, 0.0, 0.0])
        self.in_mission = True

        # initial state
        self.flight_phase = Phases.MANUAL

        # register all your callbacks here
        self.register_callback(MsgID.LOCAL_POSITION,
                               self.local_position_callback)
        self.register_callback(MsgID.LOCAL_VELOCITY,
                               self.velocity_callback)
        self.register_callback(MsgID.STATE,
                               self.state_callback)

    def local_position_callback(self):
        if self.flight_phase == Phases.TAKEOFF:

            # coordinate conversion 
            altitude = -1.0 * self.local_position[2]

            # check if altitude is within 95% of target
            if altitude > 0.95 * self.target_position[2]:
                self.landing_transition()

    def velocity_callback(self):
        if self.flight_phase == Phases.LANDING:
            if ((self.global_position[2] - self.global_home[2] < 0.1) and
            abs(self.local_position[2]) < 0.01):
                self.disarming_transition()

    def state_callback(self):
        if not self.in_mission:
            return
        if self.flight_phase == Phases.MANUAL:
            self.arming_transition()
        elif self.flight_phase == Phases.ARMING:
            self.takeoff_transition()
        elif self.flight_phase == Phases.DISARMING:
            self.manual_transition()

    def arming_transition(self):
        print("arming transition")
        self.take_control()
        self.arm()

        # set the current location to be the home position
        self.set_home_position(self.global_position[0],
                               self.global_position[1],
                               self.global_position[2])

        self.flight_phase = Phases.ARMING

    def takeoff_transition(self):
        print("takeoff transition")
        target_altitude = 3.0
        self.target_position[2] = target_altitude
        self.takeoff(target_altitude)
        self.flight_phase = Phases.TAKEOFF

    def landing_transition(self):
        print("landing transition")
        self.land()
        self.flight_phase = Phases.LANDING

    def disarming_transition(self):
        print("disarm transition")
        self.disarm()
        self.flight_phase = Phases.DISARMING

    def manual_transition(self):
        print("manual transition")
        self.release_control()
        self.stop()
        self.in_mission = False
        self.flight_phase = Phases.MANUAL

    def start(self):
        self.start_log("Logs", "NavLog.txt")
        print("starting connection")
        super().start()
        self.stop_log()

if __name__ == "__main__":
    conn = MavlinkConnection('tcp:127.0.0.1:5760', 
                             threaded=False, 
                             PX4=False)
    drone = UpAndDownFlyer(conn)
    time.sleep(2)
    drone.start()

SOLUTION:

`Phases.MANUAL`

SOLUTION:

The drone must be in the `LANDING` flight phase.
The drone must be less than 0.01 meters above ground level.

QUIZ QUESTION::

Sort the following methods into the chronological order in which they are called.

ANSWER CHOICES:

Order method is called	Method name
`self.disarming_transition()`
`self.arming_transition()`
`self.manual_transition()`
`self.landing_transition()`
`self.takeoff_transition()`

SOLUTION:

Order method is called	Method name
`self.disarming_transition()`
`self.arming_transition()`
`self.manual_transition()`
`self.landing_transition()`
`self.takeoff_transition()`