Final ReportStephen Joo and Daniel Kattan

April 16, 2010ECE 002, Group 8

Group 8

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.

Introduction

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.

Sensors Lab

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

Light 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.

Rangefinder 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.

Sonar sensor results

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

Sensor lab conclusion:

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.

Elevator Project

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

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

Elevator Project (cotd)

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

Instrumentation and Circuit Labs

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

Instrumentation Lab (cotd)

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

Circuit 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.

PSPICE Lab

PSPICE pictures

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.

AM Radio Lab:

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

AM Radio Lab (cotd)

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

Conclusion