Microcontrollers Texas Instruments MSP430

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
students


Being clear about required assignments


Different 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


Miscommunication


Meeting times


When 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 signal


Located in Ft. Collins


Transmits to entire US including Alaska and
Hawaii


Makes use of several ECE concepts


Analog Design


Communications


Microcontrollers






WWVB


Broadcast signal cycles every minute


Signal contains the following time information


Time


Date


Daylight savings


Leap year warning


Leap 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 MSP430


Decode data signal


Set clock


Control clock time during normal operation


Allow for manual setting and time zone
adjustment


Output to display

Budget


Had no operating costs during semester


Approximate 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 Morales


Help getting started


Gave assistance when needed


Dr. Bill Eads


Provided guidance and practical perspective


Burgers, brats, beer

, fishing & kayaking