© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Guard Robot Project

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Opening Activity What are some simple, common sense ways to maintain security in an office building?

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Security Security in an office setting remains important to both individuals and the company –Workers typically leave portable items of moderate value (briefcases, radios, CDs, etc.) at their desks –The company has items of significant value in every office (computers, specialized equipment like cameras) Typical Office Desk Can you spot items that are less secure?

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Security Information is also extremely important to keep safe –Company secrets –Customer information –Employee data –Computer passwords –Credit card information –Legal and other sensitive documents Sensitive Information Sensitive information was hidden in this publicly released document. What if the unmodified version were to be stolen from an unsecured office?

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Security Simple measures can help to reduce “crimes of opportunity” –Report suspicious persons –Keep track of people entering and leaving the building –CLOSE AND LOCK DOORS Open Door It doesn’t matter how many locks you have if you forget to close the door…

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Security Checking doors can be tedious and expensive –How many doors are in your school or home? –How long would it take to check them all? –How much would you have to pay someone trustworthy to check every one of those doors every night, including on weekends? –Could a robot save money here? Door Check Checking all the doors in a facility can take a very long time

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Guard Robot: Programming Review Switch Block Loops GUI image courtesy of Cybermotion

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Switch Block: Ultrasonic Sensor Switch Blocks… allow the program to observe a value, and choose between different paths of code to follow, based on the observed value. Sensor Switch Blocks… check a specified sensor to determine which group of blocks to run. Ultrasonic Sensor Switch Blocks… check an Ultrasonic Sensor reading against a pre-set threshold to decide which blocks to run. If the sensor reading is less than the threshold, the top “near” (flower) branch will run. If the sensor reading is greater than the threshold, the block will run the bottom “far” (mountains) branch. Keep Your Distance Based on the value of the Ultrasonic Sensor, this Switch will either move backward (if the sensor value is less than the threshold), or move forward (if the sensor value exceeds the threshold)

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Infinite Loop The Loop Block runs the blocks inside it over and over again, until a certain stopping condition is met. The infinite loop or “forever” loop has no stopping condition, and therefore will repeat the blocks inside over and over, forever. Back and Forth The loop causes the robot to repeat the forward-then-back motion forever

© 2006 Carnegie Mellon Robotics Academy Designed for use with the LEGO MINDSTORMS ® Education NXT Software and Base Set #9797 Simple practices like closing doors when leaving the office can help to reduce significant security risks It is time-consuming and tedious to check all the doors by hand A robot can potentially save time and resources by performing this task Summary The Ultrasonic Sensor Switch Block lets you choose which code to run based on the value of an Ultrasonic Sensor versus a threshold Loops run the same piece of code over and over again until a certain condition is met