Sentry System Integration and Action

1. Sentry SystemIntegration and Action See Teacher Guide for printing instructions

2. What do you do when faced with the following situations? Opening Activity • Suspicious person in the hallway at school • Smell of gas in your home • Lights go out in your classroom • Students fighting in the locker room • Broken bottles found on the playground

3. What do you do when faced with dangerous situations? Opening Activity • In some cases where the danger is immediate, you should take steps to ensure your own safety first • In all cases, the proper response includes alerting a responsible authority figure as soon as possible

4. How should your robot react to situations it detects? Reaction Action • What is your robot’s role and place in the security plan? • This is up to your group to determine • Consider the limitations of your robot • What you can detect • What you can actually tell based on what you detect • Physical limitations • Legal liability – even human security guards have very strict limits on their legal authority! • What are your robot’s priorities for keeping itself safe?

5. Investigation Path (b) • This version of Investigation 3 continues where the Two-Way Communication Sentry System Investigation left off • Groups that chose a One-Way system should use Investigation 3a instead

6. Logistics • The two cooperating groups will continue to work together for this project • The two sentries must perform their own lookout duties, as well as communicate with each other Two of a… Kind Of The two sentries must watch theirown posts, but also listen for alertsfrom the other unit

7. The Sensors Integration and Action:Technical Review

8. Touch Sensor • Detects physical contact • Tells you: • 1 if touched • 0 if not touched Poke, Poke? The cross axle probe inserted intothe end of the Touch Sensor contactincreases its effective range

9. Sound Sensor • Detects Sound • Tells you: • Amplitude (volume) of sound • Low numbers = quiet • High numbers = loud • Can be confused by sounds of different frequencies (pitch) Listen Carefully The Sound Sensor can detect many sounds, from gentle vibrations to jarring collisions

10. Light Sensor • Detects light intensity • Tells you: • The intensity of light detected • Low numbers = dark • High numbers = light • Light on the front can be turned on or off Light the Way The light sensor in Reflected Light modeshines its own light out and measuresthe amount that bounces back

11. Ultrasonic Sensor • Detects distance • Tells you: • Distance to a surface or object in front • Indicates a distance in cm or inches Ro-Bat The Ultrasonic Sensor uses the same basic principle for detecting distance as cave-dwelling bats do.

12. Rotation Sensor • Detects rotation of the motor axle • Tells you: • Amount the axle has rotated in degrees or full rotations • Rotational position of an attached piece* • Linear position of an attached piece* Rotato Chips The Rotation Sensor is built into theInteractive Servo Motors * If you also know the initial position and how the piece is attached, you can calculate this

13. Summary • Detection is not enough. Your robot must also be programmed to respond appropriately to anything it detects. • Furthermore, it must respond to anything the other robot detects! • This investigation is a continuation of the (b) path for two sentries; you will need your previous Investigation 2b program for this • See previous investigations or theAdvanced > Bluetooth section forBluetooth information • The two sentries should work together as partners, in a sensible way!