Bluetooth-enabled Bluetooth-enabled Thermal SensorThermal Sensor

4 December, 20024 December, 2002

Bonnie BenjaminBonnie Benjamin

Kavitha SagiKavitha Sagi

Shelly WistedShelly Wisted

ECE 345 - SchreiberECE 345 - Schreiber

Presentation OverviewPresentation Overview

Project DescriptionProject Description ChallengesChallenges Lessons LearnedLessons Learned QuestionsQuestions AcknowledgementsAcknowledgements

High-levelHigh-levelOverviewOverview

Circuit

Bluetooth LabVIEW

Circuit DetailCircuit Detail

Max 232

Amplifier

Adder

Temp Sensor

PIC16F877

Rectifier

Temp sensorTemp sensor

LM34CHLM34CH Sensor range: Sensor range:

• -50° to 350°F-50° to 350°F Range for project:Range for project:

• 68° to 105°F68° to 105°F 118 mV per °F118 mV per °F 8.44°F per V8.44°F per V

Sensor CalibrationSensor Calibration

Tempterature Calibration

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

30 50 70 90 110 130 150 170

Temperature (°F)

Vo

ltag

e (V

)

Sensor CalibrationSensor Calibrationwith trendlinewith trendline

Tempterature Calibration

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

30 50 70 90 110 130 150 170

Temperature (°F)

Vo

ltag

e (V

)

AdderAdder

Input range:Input range:• -1 to 6 V-1 to 6 V

Shifted range:Shifted range:• -1.72 to 5.28 V-1.72 to 5.28 V

Purpose:Purpose:• 0V = 68°F0V = 68°F• 0.356V = 105°F0.356V = 105°F

AmplifierAmplifier

Gain: 12.5 V/VGain: 12.5 V/V Amplified range:Amplified range:

• -5 to 5 V-5 to 5 V• Saturates at 5V Saturates at 5V

(ideally)(ideally) Purpose:Purpose:

• 0V = 68°F0V = 68°F• 4.3V = 105°F4.3V = 105°F• 0-5V range for PIC0-5V range for PIC

RectifierRectifier

Gain: 1 V/VGain: 1 V/V New range:New range:

• 0 to 5 V (ideally)0 to 5 V (ideally) Purpose:Purpose:

• Acts like clipper (0 – 5 V)Acts like clipper (0 – 5 V)

InverterRectifier

Circuit PerformanceCircuit Performance

Temp vs. Vout

0

1

2

3

4

5

6

60 70 80 90 100 110 120 130

Temperature (°F)

Ou

tpu

t V

olt

ag

e (

V)

Calculated

Measured

Saturation point at 103°

PIC16F877PIC16F877

RS232 StandardRS232 Standard• iSPAiSPA

Data transmissionData transmission• A/DA/D

10 bit conversion10 bit conversion

• USARTUSART Start and Stop BitsStart and Stop Bits Baud rate generatorBaud rate generator

= Fosc/(64(x+1))= Fosc/(64(x+1))

PIC ProgrammingPIC Programming

Basic ProgrammingBasic Programming• L.E.T PicBasic ProL.E.T PicBasic Pro• PICALLPICALL

TestingTesting• A/DA/D• USARTUSART

MAX 232MAX 232

RS 232 StandardRS 232 Standard• Converts voltageConverts voltage

Transmits bits to iSPATransmits bits to iSPA• Data rate of 9600 Data rate of 9600

High-levelHigh-levelOverviewOverview

Circuit Bluetooth LabVIEW

Bluetooth DetailBluetooth Detail

Impulsesoft Serial Port Adapter (iSPA)(from circuit)

Belkin card (PCMCIA card)(on laptop)

iSPAiSPA

Acts as a COM portActs as a COM port• Configure Configure

ServerServer Bits/sec, stop bits, flow Bits/sec, stop bits, flow

controlcontrol Testing FunctionalityTesting Functionality

• Other Bluetooth Other Bluetooth DevicesDevices

• Data TransmissionData Transmission

PCMCIA CardPCMCIA Card

ClientClient Configure as COM Configure as COM

portport• Same baud rate Same baud rate

and stop bits as and stop bits as iSPA iSPA

Data AcquisitionData Acquisition

High-levelHigh-levelOverviewOverview

Circuit Bluetooth LabVIEW

LabVIEW detailLabVIEW detailCOM port

Collect 8 bits

Convert to voltage

Convert to temperature

LabVIEW: D/A ConversionLabVIEW: D/A Conversion

LabVIEW: Final ProgramLabVIEW: Final Program

LabVIEW: Final ProgramLabVIEW: Final Program

ChallengesChallenges

Little knowledge of conceptsLittle knowledge of concepts• BluetoothBluetooth• PIC programmingPIC programming• RS232 standardRS232 standard• Data acquisition from COM portData acquisition from COM port

Wide temperature rangeWide temperature range Ordering from InternationalOrdering from International

Lessons LearnedLessons Learned GeneralGeneral

• Bluetooth StandardBluetooth Standard• LabVIEWLabVIEW• Department ResourcesDepartment Resources• Relating with customer supportRelating with customer support

ElectricalElectrical• Datasheet terminologyDatasheet terminology• Analog circuitsAnalog circuits• Lab equipmentLab equipment

QuestionsQuestions

AcknowledgementsAcknowledgements

•Shaun Anders •Dr. Jennifer Bernhard•Christian Hahn•Paul Leisher•Dan Mast•Henry Schaper•Russ Schreiber•Dr. Gary Swenson•Jim Wehmer

•Belkin•Impulsesoft•Microchip•National Instruments