I completely built the Mindstorms EV3 Spik3r. Missions 1-4 worked fine. However, with mission 5, and using the pre-made program, the robot just keeps backing up, instead of facing the bug, shooting it and then moving towards it. I put the 'bug' right in front (5cm) of the robot, and it backs up. I put the bug a bit further (50cm) in front, and the robot still just keeps backing up.
If I hold the bug in my hand and move it to about 5 cm from the sensor, above it (like a 45 degree angle), then the sensor detects the bug and the robot shoots at it and then tries to crush it. But it seems pretty flaky.
Is there an ev3 program I could download to help me debug this, or at least understand what's going on? Perhaps a program that shows the ultrasonic sensor's reading in real time on the brick so I can move the bug around and see what the readings are?
What else could I try?