F12: Evil Watchdog

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Revision as of 07:20, 30 November 2012 by Waymond f12 (talk | contribs) (Hardware Design)

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Abstract

The Evil Watchdog takes the responsibilities of a pet guarding a house. It will roam around a predefined environment, avoid obstacles, and sound an alarm whenever foreign motion is detected.

CMPE 146 F12 EWD Evil Watchdog.jpg

Introduction

The objective of this project is to design a vehicle to imitate a guard dog. The following items will be incorporated to accomplish this goal :

  • Motor driven chassis
  • Vehicle will move in a random path detecting motion
  • Vehicle will sound an alarm when motion is detected

Technology used

  • Motion sensor
  • Distance sensor

Team Members and Roles & Responsibilities

  • Waymond Chen: Front motor control and distance sensor programming
  • Hung Vuong: Distance and motion sensor programming
  • Erik Montoya: Backside motor control and programming

Schedule

Starting Ending Planned Activities Actual
Oct 26, 2012 Nov 1, 2012
  • Acquire parts
  • Identify interfaces to be used
  • Identify pin selections
  • Review datasheets
  • Received distance sensors
  • Received motion sensors
Nov 2, 2012 Nov 8, 2012
  • Build chassis
  • Build motors and wheels
  • Test motors and wheels
  • Prepared chassis and wheels
  • Tested motors and steering
Nov 9, 2012 Nov 15, 2012
  • Write PWM driver
  • Control rear wheels
  • Program and test distance sensors
  • Created PWM driver
  • Began controlling rear wheels
  • Successfully tested distance sensors
Nov 16, 2012 Nov 22, 2012
  • Integrate motion sensors
  • Test motion sensors
  • Control/steer front wheels
 
Nov 23, 2012 Nov 29, 2012
  • Integrate alarm system
  • Unite all parts
 
Nov 30, 2012 Dec 6, 2012
  • Testing and design final product
  • Complete and revise project report
 
Dec 7, 2012 Dec 13, 2012
  • Finalize and deliver project
 

Parts List and Costs

The following table will be updated as parts arrive.

ItemSource Cost Ea. Qty. Total
Alarm RadioShack $3.69 x1 $3.69
ARM7 NXP LPC2148 Microcontroller SJValley Engineering $60.00 x1 $60.00
Batteries - AA Costco $1.33 x5 $6.65
Chassis, Motors, and Wheels Fry's Electronics $15.34 x1 $15.34
Distance Sensors (3)* SJValley Engineering $25.00 x3 $75.00
LEDs HSC Electronics $0.35 x2 $0.70
Motion Sensor* Preet Kang      
Motor Controllers (2)* SJValley Engineering $35.00 x2 $70.00
Voltage Regulator - LM7805CV HSC Electronics $1.99 x1 $1.99

*generously provided by Dr. Ozemek and Preet Kang

Design and Implementation

Hardware Design

Original toy car prior to disassembly.
For convenience, a New Bright toy RC car was purchased and disassembled. The motors and wheels were already pre-mounted onto the chassis, allowing electronic parts to control the car. On the chassis, slots above the wheel wells were large enough to house motor controllers while the center of the chassis provided enough room to include a small breadboard and the microcontroller. All wires were shortened to the shortest length possible to reduce clutter.

The sensors, which guided car control, were strategically mounted in front and above the car. This increased visibility of the sensors. Three distance sensors were used to detect obstacles: a left-, a center-, and a right-side sensor was used to determine steering of the vehicle. A front-mounted sensor would seek motion as the car was stopped. Should motion be seen, the piezo buzzer sitting at the front of the car would promptly be sounded.

Hardware Implementation

Software Design

Software Implementation

Testing and Technical Challenges

Conclusion

References