Control of an RC car via an M68HC11 microcontroller

1
Control of an RC car via an M68HC11
microcontroller

• ECE 345 - Senior Design Project
• Paul Whitaker and Robert Swanson

2
Introduction

• Why we chose this project
• Practical applications

3
Project Block Diagram
4
Introduction

• Why we chose this project
• Practical applications

5
Hardware Design

• Transmitter
• Switching circuitry
• Keypad with input encoder
• GPS equipment

6
Analog Switch Operation
Harris HI-300 CMOS Analog Switch
Pads on remote control unit circuit board
Input from Port B of microcontroller

• Output nodes become connected together when the
  input goes high

7
Hardware Design

• Transmitter
• Switching circuitry
• Keypad with input encoder
• GPS equipment

8
Keypad Encoder Operation
National Semiconductor MM54C922 16-Key Encoder
Outputs to microcontroller Port C
Row and column inputs from Grayhill 4x4 Matrix
Output Keypad
9
Hardware Design

• Transmitter
• Switching circuitry
• Keypad with input encoder
• GPS equipment

10
Software Design

• Command output
• Keypad input
• Preset motion sequences
• Time delay subroutine

11
Simplified Software Flowchart
Begin loop
Directional signal?
Send begin motion signal
YES
NO
Sequence signal?
Execute preset motion sequence
YES
NO
12
Project Economics

• Parts
• Labor

13
Parts

• GPS receiver
• Radioshack Jammer
• Motorola M68HC11
• Total parts cost

• 268
• 39
• 199
• 506

14
Labor

• Total person-hours
• Hourly salary
• Labor cost
• Support factor
• Total labor cost

• 160
• 25
• 4,000
• 2.5
• 10,000

15
Project Economics

• Parts
• Labor

• Total cost 10,506

16
Project Accomplishments

• Used a microcontroller in conjunction with
  assembly code to control a complex system
• Gained experience interpreting component
  specifications and datasheets
• Implemented a matrix-style input keypad

17
Educational Benefits

• Improved our analytical abilities by determining
  the functionality of undocumented hardware
• Developed our leadership and teamwork skills
• Gained experience working under project deadlines