What is a Microcontroller?

Computer on a Chip

Microprocessor

Input / Output

RAM and/or ROM

Signal Processing

Microcontrollers Are Everywhere

Automotive Manufacturing Robotics Medical Aeronautics Mobile Devices

ECE 251 – Microprocessors Taught with a

Freescale Microcontroller

MC68HC12 Development Board

$80 Per Board $30 Covered By ECE

Department $50 Cost to Students

Texas Instruments MSP430

Popular TI Microcontroller Low Cost ~ $20 Portable USB Interface Same Relevant Features

as the Freescale Product Superior Development

Software For Students

Why Switch?

Freescale $80 Per Student Aging RS232

Interface CISC Architecture

Lots of instructions

Text Based Development Interface

TI MSP430 $20 Per Student Commonplace USB

Interface RISC Architecture

Few Instructions

Windows Style Visual Development Interface

Development of Labs

Group redesigned labs 3-10 of ECE 251 for use with TI-MSP430

Miguel completed labs 3, 7, 8 & 9 We completed 4, 5, 6 & 10 Also 2 practical exams We revised Miguel’s labs extensively

and wrote solutions Made the labs ready for student use

ECE 251 MSP430 Labs

Lab 3 – Introduction to the MSP430 Lab 4 – Addressing Modes Lab 5 – Subroutines and the Stack Lab 6 – BCD Math Lab 7 – Parallel I/O Lab 8 – Interrupts Lab 9 – Timer Module Lab 10 – A/D Converter

Working With Students

All inexperienced as TAs Had to learn to communicate with

studentsBeing clear about required assignmentsDifferent perspective when writing labs

Had to learn to teach effectively

Issues We Faced No keyboard/console capability (Lab 4) RISC vs. CISC architecture (Lab 6,

Lab 10) Clock inaccuracy (Lab 9) Fewer I/O pins (Lab 10) USB tool only worked on installed

computer

Solutions to Issues

Focused on what MSP430 does have Provided subroutines to students Experimented with different ways to

output to 7-segment display Considered ways to integrate labs

What Didn’t Go So Well

MiscommunicationMeeting timesWhen assignments were due

Students had trouble being responsible for both microcontrollers

What Went Well Gained experience with the MSP430

which will be applied to design project Students enjoyed flexibility of USB Able to use material from the 68HC12

labs Completed lab set if transition is made

(course needs textbook)

What Went Well (Cont.) Interest from Rice University More intuitive development tool Invitation to present at TI developers

conference session on Education Working with Dr. Eads

Future Plans

Design of a self-setting clock which makes use of the WWVB radio signalLocated in Ft. CollinsTransmits to entire US including Alaska and

Hawaii

Makes use of several ECE conceptsAnalog DesignCommunicationsMicrocontrollers

WWVB Broadcast signal cycles every minute Signal contains the following time information

TimeDateDaylight savingsLeap year warningLeap second warning

Design Phase Overview

Receiver/Amplifier

Decoder Clock Display

TI-MSP430

Local Temperature

Sensing

RF remote Temperature

sensing

Extras, Time permitting

Solar Power

Generation

Alarm Capabilities

Design Phase Details

Build receiver circuit for pulse width modulated 60kHz signal

Program MSP430Decode data signalSet clockControl clock time during normal operationAllow for manual setting and time zone

adjustmentOutput to display

Budget

Had no operating costs during semesterApproximate donation of $700 from Texas

Instruments in microcontrollers and development kits

Still have $300 remaining in budget for design phase

Acknowledgements

Thanks to Texas Instruments for the hardware donations

Miguel MoralesHelp getting startedGave assistance when needed

Dr. Bill EadsProvided guidance and practical perspectiveBurgers, brats, beer , fishing & kayaking