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Autonomous Fire DetectorsAutonomous Fire Detectors
Presented by:
Jason Faulring
October 7, 2002
Project Update
Goals of ProjectGoals of Project
l Rapid development of a prototype boardthat can be adapted to many applications
l Development of embedded software tooperate onboard devices
l Development of PC side software to extractcollected data from boards
l Develop mechanical enclosures for boardsfor field applications
ApplicationsApplicationsl Handheld Thermistor Loggerl Thermocouple Fire loggerl Fire Sentryl Fire Sentry/Data Acquisitionl Lake Drifterl Pond Monitorl Automated Ground Truth Loggerl Air born ATV/APRSl Lake Depth feature loggerl 1 – Wire Weather Station Logger
First Application: Handheld LoggerFirst Application: Handheld Logger
l Acquire precisiontemperature andlocation data
l 64 K memory = 1771sample storage space
l Uses standard GPS unit
l PC application placesdata directly into Excel
Handheld LoggerHandheld Logger
l Precision Thermistor module: self containedunit accurate to 0.01C
l Interfaces with any GPS capable of NMEA0183 output.
lMinimal number of components on boardnecessary for operation
l “Off the shelf” components minimizesdevelopment time
Visual Basic Based ApplicationVisual Basic Based Application
Rugged Fire LoggerRugged Fire Loggerl Utilizes 4 ADC channels
for thermocouple data
l RTC and Position viaGPS
l Field controllable using aPalm Pilot
l Rugged NEMA enclosuresuitable for hostileenvironments
l VB download application
l 12 bit, 8 Channel ADC, 1.22mV/digital count
l Single part thermocouple amplifier with avoltage divider for level conversion
l ADC will accept input from any sensorproducing output levels 0V – 5V
l 16 Pin header allows for easy implementationof a sensor daughterboard if necessary
Rugged Fire LoggerRugged Fire Logger
Rugged Fire LoggerRugged Fire Logger
l Provides a base platform for building a firesentry system
l Utilize other 4 ADC channels to detectother aspects of fire
l Set thresholds for alarm notification
l Add the synthesizer or modem to provide ameans to alert field workers
l Utilize power management circuitry toextend battery life for longer operation
Design MethodologyDesign Methodology
l Utilized existing work done with BasicStamp, rapid development environment
l Utilized existing choices for Thermistor,ADC, Memory and Voice Synthesizer
l Added components for power management,wireless digital data transfer & radio control
l Designed schematic for interfacing of allcomponents
Resulting SchematicResulting Schematic
Surface Mount BoardSurface Mount Board
Full Stuffed BoardFull Stuffed Board
Lake DrifterLake Drifter
l Currently exploring packaging options withRIT ME Dept.
l Defining target sensors to be used
l Looking at pros/cons of using a mooredbuoy or a free-floating package
l Developing a wireless packet basedprotocol for remotely downloading datafrom the device
Wireless CommunicationWireless Communicationl Utilizing MXComm 614 modem chip
l Generates AFSK signal from simple serialdata @ 1200 baud
l AFSK passed wireless via 2 meter amateurradio, can use almost any frequency radio
l AEA PK232 modem used for base stationreceive, may be replaced with single chipmodem
l Half duplex operation allow remote controlof logger
Wireless, contd.Wireless, contd.
SOH SOH KB2WLK ID ID CMD…
Packet Formation
Start ofheader($01)
Call signfor legalamateur
operation(6 bytes)
UnitID
Dest.ID
Command
Wireless, contd.Wireless, contd.
Packet Formation
…16 bytes of data Checksum EOT EOT
Calculated forError Correction
End ofTransmission
($04)
Checksum Poly
051216 xxxx +++
Data to be sent(commands, stored
or live data)
Wireless, contd.Wireless, contd.Command Field
Command PurposeA Acknowledge TransmissionB Dump MemoryC End of MemoryD clear memoryE gets current latitudeF gets current longitudeG gets the current timeH gets the current dateI gets the value for specified AD channel in data fieldJ gets the value for the thermistorK indicates there is data in the data fieldL resend last packet
Wireless, contd.Wireless, contd.
l Initially, non-digipeated protocol
l All transmissions are followed by an ACKpacket by receiver
l Speak when spoken to
l Room for some command set expansion,limited by code space and RAM
BathometryBathometry
l Utilize DGPS and a sonar device to map thebottom of a lake
l Garmin Fishfinder 100 provides depthinformation via a NMEA 0183 sentence
l Very rapid development, got fish finder onFriday morning: Friday afternoon softwareand electronics hardware is ready to run
l Building a library of functions that can beeasily adapted to most applications
Questions and Suggestion forQuestions and Suggestion forother future applicationsother future applications
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