mid-semester presentation senior design i february 24, 2011
TRANSCRIPT
Mid-Semester Presentation
Senior Design I
February 24, 2011
Child Safer Seat
Child Safer Seat Team
Dr. Raymond WintonAcademic adviser
Blake Bennett EE
ProgrammingTechnical
Documentation
Ayman Busaad
EEHardware
Implementation
Hardware Design
Chris Howell EE
Hardware DevelopmentTechnical
Documentation
Kenneth Gustine
EEProgramming
Website design
• Problem
• Solution
• Block Diagram
• Constraints-Technical-Practical
• Trade-off
• Progress
• Timeline
• Questions
Outline
The interior temperature of a car can rise by 20°F within only ten minutes which can cause a child death due to hyperthermia. [1]
Before airbags, 1990 – 1992: 11 deaths due to hyperthermia [1]
After airbags, 2006 – 2009: 108 deaths due to hyperthermia [1]
Problem
Combined a device with a car child seat which can determines when a child is in danger due to extreme temperatures and alerts help if a situation becomes hazardous.The device can alert via text messaging (SMS) to a
number that is programmed into the device.
Solution
Block Diagram
Thermo Sensor
Processor
Power Supply
PressureSensor
Antenna
Technical ConstraintsName Description
Compatibility Device must be compatible with standard cellular networks.
Weight SensingDevice must be capable of detecting the presence of a child weighing at least five pounds in a safety seat.
Temperature SensingDevice must measure ambient temperatures from 30° to 100° Fahrenheit.
Temperature Operation Device must operate from 0° to 180° Fahrenheit.
Battery LifeDevice must have a minimum battery life of three months under normal operating conditions.
Practical Constraints
Type Name Description
Sustainability Maintainability Battery replacement or recharging must be a convenient,intuitive process.
Manufacturability Personalization Device must be programmable with multiple user phonenumbers.
Battery replacement or recharging must be a convenient, intuitive process
Sustainability: Maintainability
Device must be programmable with multiple user phone numbers.
Manufacturability: Personalization
Cellular Network Trade-off
Service Network Price Setup Providers Coverage Storage
GSM Lowest Easy Many Plentiful SIM card
CDMA Medium Complex Many Plentiful None
GSM Trade-OffManufacturer Model Advantages Disadvantages
Telit GC864 PYTHON, ADC/DAC, Price No breakout boardNo antenna connector
Siemens GSM/GPRS modem MD720-3
Everything set up Very Expensive
Telit GE865-QUAD PYTHON, antenna connector, ADC/DAC, Price, breakout board
No on board SIM
Telit GM862-QUAD PYTHON, GPS, on board SIM and antenna connector
Very Expensive
Force Sensitive ResistorAdvantage: Can be easily integrated into child seatDisadvantage: Analog signal transmitted to system
Snap-action Pushbutton SwitchAdvantage: Binary signal transmitted to systemDisadvantage: Maybe difficult to integrate into car seat
Pressure Sensor Trade-Off
Options Advantage Disadvantage
AA batteries •Ease of replacement•Low initial cost
•Ongoing battery cost
Battery Pack •Low maintenance cost•Manufacturer controls battery type
•Higher initial cost•Charging inconvenience
Vehicle Power Supply •No batteries•Smaller device
•Inconvenient to user•External wires•Power stops with removal of keys
Power Source Trade-offs
Temp Sensor Trade-off
Options Disadvantages Advantages
Digital •Higher power consumption
• Easy to Sample• More Accurate• Output less susceptible to Noise
Analog • Less Accurate• Noise susceptibility
• Lower power consumption• Precision only dependent on microcontroller’s ADC
GSM module : Telit GE865 Received, on boardTemp sensor: LM60 Received, on boardAntenna: Received, on boardSIM card holder: Received, on boardPressure sensor: ResearchingPower Supply: Researching
Progress
Progress cont.
Timeline
Time line January Febuary March April
Research
Hardware Testing
Programming
Prototype Testing
Optimizing
[1] J. Null. (2011, January 17) Hyperthermia Deaths of Children in Vehicles. [Online]. Available: http://ggweather.com/heat/
References
Questions