Download - The University of Tennessee Knoxville GROUP 7

The University of Tennessee KnoxvilleGROUP 7

MSP430 PresentationSaturday, April 22, 2006-Jason Bault-Darren Giles-Nathan Rowe-Trevor Williams

ECE 300 MSP430 Project

MSP430

Presentation Topics Project Objectives Specifications Board Design Pressure Sensor Temperature Sensor Sensor Code Modifications Results and Discussion Conclusion


Objectives

Use the MSP430 chip on a circuit board that uses sensors to detect temperature and pressure

Program the sensor logic into the microprocessor

Apply fundamental circuit knowledge to a practical application of circuit design

Learn how to solder elements to a circuit board


MSP430 Specifications

Low Supply-Voltage Range, 1.8 V to 3.6 V Ultralow-Power Consumption:

Active Mode: 280 A at 1 MHz, 2.2 V Standby Mode: 1.1 A Off Mode (RAM Retention): 0.1 A

16-Bit RISC Architecture,

125-ns Instruction Cycle Time 12-Bit A/D Converter With Internal

Reference, Sample-and-Hold and Autoscan

Feature Integrated LCD Driver for Up to

160 Segments MSP430F449:

60KB+256B Flash Memory,

2KB RAM


Board Design

Resistors and Capacitors were fairly easy to apply with small dabs of solder

Topleft: LCD Was simple to apply to circuit board, used a little solder on each pin through holes

Center: MSP430 chipMost difficult component to install, required preciseness and lots and lots of patience


IESP-12 Pressure Sensor

Detects Force in units of kgf (kilograms force)

Max load of 4.0kgf Life: >= 100,000 cycles @

1.5kgf Operating Temp: +10 to

+40 Celsius Storage Temp: -40 to +70

Celsius Supply voltage: 3-6 VDC Current: 5 mA Max Current: 20 mA Max voltage: 30 VDC


AD590 Temperature Sensor

Low power requirements Voltage supply range of 4 to

30 VDC 1.5 mW @ 5 V @ 25 Celsius

High output impedance from supply voltage drift and ripple Small amount of error from

changing the power supply Electrically durable

With stands forward voltage of up to 44 V and a reverse of

20 V to resist damage


Sensor Code Modifications

Modified sensor read-in code for pressure sensor

Used more accurate scaling coefficient according to our design

Added a filter initializing variable to the first filter sampling instead of the forth. This allows the reading

to display more accurately on the first sample.

float CDEG,FDEG,XIN, Y,SIGK;

bool initializeFilter = false;

const float A = 0.613;

const float B = .19380;

float XIN7, XIN6, XIN5, XIN4, XIN3, XIN2, XIN1;

-------------------------------

XIN = ADC12MEM6 * A * B;

-------------------------------

if(initializeFilter == false){

XIN7 = XIN;

XIN6 = XIN;

XIN5 = XIN;

XIN4 = XIN;

XIN3 = XIN;

XIN2 = XIN;

XIN1 = XIN;

initializeFilter = true;

}


Results & Discussion

Correctly displayed force

Correctly displayed temperature

Correctly displayed output within a reasonable range

Our group did not use a 741 operational amplifier for the gain. Instead we replaced the op amp and the 1K resistor with one 5 k resistor to duplicate the gain of five.


Problems

Soldering Issues- Trouble with pins holding

Programming Issues- Application wouldn’t accept arrays for a more robust filter program

Display Issues- Missing segments at random- Dim display at random

· Believed to be issues with the microprocessor

From Group 7