Safety Motion Detector Mid-Semester Presentation Senior Design I October 4, 2011

Safety Motion Detector Team Alden Stennis Jason Smith Programming Sensors Geoff Jakins PCB Design Website PCB Design Sensors Dr. Donohoe Faculty Advisor Electrical Engineer Programming Sensors Electrical Engineer Justin Parker Electrical Engineer

Outline Problem Solution System Overview Constraints Technical Practical Design Choices Progress Timeline

Problem and Solution

Problem Utility workers alone are in the field getting injured and are unable to receive help within a reasonable amount of time. There are approximately 600 deaths yearly from falling accidents in the work field.

Solution Safety Motion Detector – Wrist device monitors user’s movement – Signals the base station when no movement is detected

System Overview (Wrist Device) Motion Sensor Power Supply Transceiver MicrocontrollerInterface

Technical and Practical Constraints

Technical Constraints ConstraintDescription NotificationsVisual displays must indicate the safety status based on the user’s movement. Transmission DistanceThe base station must communicate data with the detection unit up to 200 feet. Battery LifeThe batteries must last for at least 24 hours. Temperature RangeThe SMD must withstand temperatures in the range of -40° to 185° F. Motion Detector Sensitivity Minimal motion, acceleration between -1.5 and +1.5 g 0 with minimum increments of 0.1 g 0 must be detected along one or more axes.

Practical Constraints TypeNameDescription ManufacturabilitySize The dimensions must be no larger than 3” wide, 3”long and 1.5” high SustainabilityRuggedness The wearable device must be capable of withstanding everyday use in the field.

Manufacturability Device must be small in size – Device will be no larger than 3” wide, 3” long, and 1.5” high – Must be wrist wearable to increase efficiency – Must not interfere with the user’s work

Sustainability Must withstand everyday use in the field – Water resistant – Function properly in hot or cold weather conditions Device encasement durability – Strong enough to handle accidental impact

Design Choices

Microcontroller ModelSleep Current PortsVoltageComponent Chosen Pic24FJ64GA10220 nA (Deep Sleep) 2 - UART 2 - SPI 2 - I2C V Pic24HJ32GP2026 mA 1 - UART 1 - SPI 1 - I2C V

Microcontroller ModelSleep Current PortsVoltageComponent Chosen Pic24FJ64GA10220 nA (Deep Sleep) 2 - UART 2 - SPI 2 - I2C V Pic24HJ32GP2026 mA 1 - UART 1 - SPI 1 - I2C V

Motion Detector DeviceProsConsSelection GyroscopeCan sense orientation accurately Cannot detect omnidirectional movement AccelerometerCan sense movement in any direction Cannot detect constant velocity Mercury sensorSimple Design, Small Operating rate is very slow, Cannot measure complete range of motions

Motion Detector DeviceProsConsSelection GyroscopeCan sense orientation accurately Cannot detect omnidirectional movement AccelerometerCan sense movement in any direction Cannot detect constant velocity Mercury sensorSimple Design, Small Operating rate is very slow, Cannot measure complete range of motions

Accelerometer DeviceAxesOutput TypeInput Voltage Selection AD22285-R22Analog3.5 – 6 V MMA7660FCT3Digital2.4 – 3.6 V ADXL3353Analog1.8 – 3.6 V

Accelerometer DeviceAxesOutput TypeInput Voltage Selection AD22285-R22Analog3.5 – 6 V MMA7660FCT3Digital2.4 – 3.6 V ADXL3353Analog1.8 – 3.6 V

Wireless Communication DevicePower Consumption Data RateComplexitySelection ZigbeeVery Low20, 40, and 250 Kbits/s Low WiFiHigh11 and 54 Mbits/s High BluetoothMedium1 Mbits/sHigh

Wireless Communication DevicePower Consumption Data RateComplexitySelection ZigbeeVery Low20, 40, and 250 Kbits/s Low WiFiHigh11 and 54 Mbits/s High BluetoothMedium1 Mbits/sHigh

DeviceCurrent draw (transmitting) Transmission range (Outdoor) Internal Antenna Selection XBee45 mA300 ftyes XBee Pro215 mA1 mileyes XBee Pro - XSC 265 mA6 milesno Zigbee

DeviceCurrent draw (transmitting) Transmission range (Outdoor) Internal Antenna Selection XBee45 mA300 ftyes XBee Pro215 mA1 mileyes XBee Pro - XSC 265 mA6 milesno Zigbee

Progress and Timeline

Wrist Device

Microcontroller

Wrist Device Accelerometer

Wrist Device Transceiver

Wrist Device Notifications

Base Station

Microcontroller

Base Station Transceiver

Base Station Notifications

Timeline AugustSeptemberOctoberNovember Research Ordering Parts Design Programming And Construction Prototype

References [1] "Census of Fatal Occupational Injuries (CFOI) - Current and Revised Data." U.S. Bureau of Labor Statistics. Web. 07 Sept [2] “Pic24FJ64GA102” [3] ”Pic24HJ32GP202” [4] ”AD22285-R2” [5] “MMA7660FCT” [6] “ADXL335” [7] “How does ZigBee compare with other wireless standards?” [8] “Xbee, Xbee Pro, Xbee Pro XSC” Page 5

Safety Motion Detector Mid-Semester Presentation Senior Design I October 4, 2011