Answer Key: EV3 - Switch-Loop Assessment

1. This new Orchard Challenge has obstacles placed throughout the challenge. There were no obstacles in the original Orchard Challenge.

2. The Switch-Loop allows the program to effectively check two sensors (one controlling the switch, the other controlling the loop) at the same time.  So both the obstacle detection with the ultrasonic sensor and the distance traveled with the rotation sensor and be checked simultaneously.

3. The Loop exit control could be controlled by time (number of seconds, or forever) or any other sensor.

4. The robot will not be checking the Rotation Sensor in time and the robot may not stop. The Wait Blocks hold up the program and the Rotation Sensor is only checked at the end of the loop.

5.Ziffle’s program will not detect obstacles constantly.  Since the Move block on the lower branch is set to move for a fixed number of rotations, the robot will move forward this set amount before it checks the Ultrasonic Sensor again.  For continuous obstacle detection, Ziffle needs to set the lower Move block to "On" for duration.

6. The program only run for a few milliseconds, since the loop will only run 10 times and then stop, regardless of the light level.