Final Report

1. Final Report Stephen Joo and Daniel Kattan April 16, 2010 ECE 002, Group 8

2. Group 8

3. Introduction • We, Stephen Joo and Daniel Kattan are Group 8 of ECE 002. Throughout the semester, we have learned many things with each lab. We have faced many challenges and through them learned a lot. The different projects in ECE 2 gave us a taste of what’s to come in the next few semesters of engineering here at GW.

4. Sensors Lab • Lab introduced different types of sensors • Taught how to test different sensors to determine optimal range of use as well as how to write program using those sensors Sensors tested: • light sensor • sonar sensor • optical rangefinder • touch sensor These were critical in next project, creating and programming an elevator.

5. Light Sensor results • Provided fairly stable results over the entire spectrum • Useful for wide range of applications • Can reliably detect differences between not only white and black but also different scales of gray • Can be used to detect subtle changes in lighting, not just shift from black to white

6. Rangefinder sensor results • Results somewhat unpleasant because only accurate within certain range • According to results, sensor goes haywire and gives extreme values or values that are indiscernible from those around them (i.e. nonlinear) just outside of small normal range • Makes this sensor ill-suited to all but very crude applications.

7. Sonar sensor results • Results extremely accurate and precise • When we made graph based on data, sensor provided extremely linear graph. • Sensor is ideal for any application for measuring distances since it provides consistent and stable results at any certain distance.

8. Sensor lab conclusion: • Results from these tests greatly influenced which sensors to use for elevator project • We decided to use Because sonar sensor had such linear and stable results, it as primary sensor for elevator • Rangefinder had varied results and felt it would be unreliable for use in project • Didn’t use light sensor either because it had little use in our design

9. Elevator Project • Unique design: using only one sensor, which is sonar sensor • Elevator call buttons were start and stop buttons on Handyboard • Group felt we would have a simpler code by using only one sensor • While somewhat true, the code became more complicated to write than initially anticipated Trials: - rewrote code several times until got it working properly. - had to fine tune timing of the elevator car.

10. Elevator Project (cotd) Design: • simple and easy to construct and was reliable in its operation • streamlined stopping to simply turning off motor • enough friction was built into raising/lowering mechanism to ensure elevator stayed in place whenever motor was off

11. Elevator Project (cotd) • Work on elevator: mostly Daniel Kattan • Work on elevator code: mostly Stephen Joo • We did a lot of work together to ensure that physical elevator would work properly with the code

12. Instrumentation and Circuit Labs • Instrumentation lab exposed us to different instruments used by computer engineers • Oscilloscope used for measuring voltage changing with time and displays it in graphical format • Voltage displayed as sine wave (if AC current) • Used to display most EM waves • Dials on control panel are manipulated to produce unique graph shown on display monitor • Input channels allow cables of two distinct functions via two channels • Oscilloscope includes function generator which can easily change amplitude, frequency, shape of the graph, and more • Allows one to see how things should look before testing his/her circuits

13. Instrumentation Lab (cotd) DC power supply source: - gives varying amounts of power to circuits - used to supply constant voltage to circuit; this voltage can be changed to see how circuit reacts to different voltages - many of these changes are measured using oscilloscope

14. Circuit Lab • In another lab, we used breadboard to build physical circuit and connect it to DC power supply source for power • We measured voltage, current, and resistance at different points around circuit • Lab allowed us to actually see what we learned in class; by actually building and measuring the circuits, we understand better what is going on

15. PSPICE Lab Simulation Program with Integrated Circuit Emphasis: • used for analog and digital circuit design and educational purposes • we designed circuit blueprints via this program by adding various resistors, capacitors, voltage sources, ground, and link them all together into uniform circuit • program allows you to test various circuits to ensure working design before actually building them • by building/testing circuit in PSPICE before physically building it, engineers can try out different designs and save time and money The following two images are circuit designs of various homework problems.

16. PSPICE pictures

17. AM Radio Lab: • Learned how to make own AM radio by soldering and connecting parts from AM radio kit • Learned how to solder correctly • Split up work of soldering parts evenly between two of us so both got practice soldering joints • Once radio was complete, we could use oscilloscope to test frequency of incoming signal.

18. AM Radio Lab (cotd) Problem: - trouble with larger solder joints because soldering iron didn’t get hot enough to melt solder quickly Solution: - soon figured out that if we held soldering iron against joint and wire for minute or two it heats up enough to allow solder to flow evenly over joint • Would have been helpful to have different tips for soldering iron to have greater precision for our work

19. Conclusion • Overall, the projects have helped us become better engineers and better team players • We encountered many problems faced by engineers like coordinating the simultaneous development of hardware and software. • We became better team players through our need to finish projects outside of classtime