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
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
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
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