Navigational Aid for a Blind Deaf Individual Konrad Ahlin Ben Davidson Bob Evans Jackson Lamp David Sachenik Rob Steigerwald David Yip

Design Goals  Able to communicate effectively with deaf blind individuals  Weight cannot exceed 4 ounces  Must fit within a 4 x 2 x 1 inch volume  Must be reasonably inconspicuous  Will track position using RFID tags  Power must last for ten twenty minute uses  Cost to produce must not exceed $700 *antenna not counted in weight and size requirements

Concerns  Volume Constraints  Weight Constraints  Heat Dissipation  Attaching device to belt  Program Accuracy  PCB Design and Functionality

Size of Components Components Length (in)Width (in)Height (in)Inch cube Microcontroller Reader Keypad Battery Magnetometer

Size of Components Cont’ ComponentsDiamHeightInch cube Side Motor Side Motor Middle Motor TOTAL VOLUME: 3.802

Outer Dimensions Component Length (in)Width (in)Height (in)Inch cube Main Case Component Diam (in)Height (in)Inch cube Side Case Components Inch cube Total Volume: 9.44

Weight of Components ComponentsWeight (oz) MicrocontrollerTBD Reader0.441 KeypadTBD Magnetometer0.028 Battery.77 Side Motor0.229 Side Motor0.229 Middle Motor0.060 Case Total1.18 TOTAL:3.069

Power Consumption RFID Antenna1.5796W*hr Motors W*hr MCU W*hr Magnetometer0.0913W*hr Keypad W*hr Sum W*hr Battery is 3.7V, 1100mA*hr, 4.01W*hr

Heat Analysis – Hand Calculations  Conduction caused by air:  Section of chip 0.1” x 0.1”  A=6.45*10 -6 m 2  Q= -KA (dT/dx)  Q Total =1.6W  Q Part =1.6W/210 = W  K= (about) Wm -1 K -1  dT/dx = Q/(-KA)  dT/dx = /(0.0257*6.45*10 -6 ) = degC/m =649 degF/in =64.9 degF/0.1in Chip Air

Heat – Experimental Results Null hypothesis: Average temperature < 120 deg F 95% Confidence Alpha = 0.05 Mean=113.9 P-Value=1.00 Fail to reject null hypothesis

Heat – Analytical Analysis Case thermal conductivity = 0.2 Wm -1 K -1 Outside case temp set to 20 deg C Top of chip set to 54 deg Celsius (130 deg F) Bottom of chip insulated

1) Region Map 2) Nearest Tag ID(s) 3) Destination 9) Charging Power 20) Off Path 21) Hardware Health 22) Movement Instructions 5) Receive Map Info 12) Record location history 14) Regulate Power Enclosure: Support & Manage Internal Components 7) Receive User Input 13) Calculate path 8) Determine Orientation (Compass) 6) ID current location 11) Compare current to map 16) Calculate next movement instruction 18) Deliver Non-Prompted Information to User Via Haptic Feedback 15) Monitor Hardware Health (MCU: Define Interfaces with Power, User Input, Map Input, RFID Reader, Magnetometer, Output Drive Circuitry) 10) On- Board Power Navigation Loop Battery Life Connectivity of Modular Devices 19) Deliver Prompted Information to User Via Haptic Feedback 23) On Correct Path 24) Button Pushed 25) Estimated Remaining Distance 17) Estimate Remaining Distance 4) User Input Destination Arrival Turn Functional Decomposition

Final Design  Design elements kept from previous years  RFID tag and reader  Keypad input  Changes from previous years  Vibratory haptic feedback  Two motors for directional feedback  One motor in base unit for input confirmation  Modular belt design  Two motors  Base unit with keypad  Separate antenna

Schematic of Build (outer case)

Schematic of Build (Battery)

Schematic of Build (RFID)

Schematic of Build (PCB)

Schematic of Build (Keypad)

Schematic of Build (Cover)

Schematic of Build (Motor Case)

Procedure of Build  Week 1  Motor Testing (without case)  Antenna Testing  PCB Prototyping Board  Week 2  Finalize design and build motor case  Motor Tests (with case)  Testing of Magnetometer  Order Wiring and Belt  Week 3  Order Base Case  Test Keypad

Procedure of Build Cont’  Week 4  Test PCB  Start design for part placement in case  Order spacers and insulation for case  Have developed program to start testing  Week 5  Re-machine Case and continue fitting parts  Test connections and interactions between MCU and other devices  Order PCB  Week 6  Test Durability of general design  Finish Full Build  Week 7  Application testing of device  Week 8 – 10  Presentation Set up

Haptic Feedback Motors Navigation Feedback  Precision Haptic 10mm Vibration Motor - 15mm Type Input Confirmation  Pico Vibe 12mm Vibration Motor - 3.4mm Type

Motor Tests  Volt Step Testing  Orientation Testing  Case Material Testing  Duty Cycle Testing  Applied Force on Case

Motor Testing Results VoltageCurrent (mA)VibratingIntensity Best Orientation no N/A no N/A 0.341no N/A no N/A yeslightN/A yeslightN/A yesmoderateN/A yesmoderateN/A yesmoderateN/A yesmoderateN/A yeshighN/A yeshighN/A 1.3xxx

User Inputs Command/ RequestStep 1Step 2Step 3 Guide to room #??????* Enter 6 Didgit room number* Guide to Closest Bathroom*1* Guide To Closest Water fountain*9* Test Left Motor*4* Test Right Motor*6* Test Center Motor*5* ETA /On-Track*0* Cancel Request## Enter Sleep Mode*#* User Confirm**

Outputs to User (Automated) Output to User Duration of Vibration (s) Time Between Vibrations (s) Frequency (Hz) Duty Cycle (%)Which MotorRepeat Turning Warning Pulse2N/A Turn Side Motor Test on entered testing instruction. Pulses and then turns off Turning Vibration Turn Side Motor Continues to cycle until turn is accomplished or off track instruction is activated Warning Battery Low Both Side Motors Goes throught the cycle till use confirms they understand Warning for Off_Track Center Motor Goes throught the cycle till use confirms they understand Destination Arrival Confirmation Both side Motors Goes through the cycle till use confirms they are in the room

Outputs to User (User Generated) Output to User Duration of Vibration (s) Time Between Vibrations (s) Frequency (Hz) Duty Cycle (%)Which MotorRepeat ETA Center Active on user instruction. Pulses for the number of tags in list still to come Testing Vibrations1N/A Tested Motor Test on entered testing instruction. Pulses and then turns off Number Button Push Confirmation Center Vibrates for number of pulses equal to numeric number of button

Testing of Total Design  Heat  Internal Temperature must be less than 120 degrees Fahrenheit  Drop  Must be fully functional after a free fall drop from 3 feet  Guidance  Must accurately guide an individual from any location on the second floor of Building 9, to any designated location

Testing of Total Design (cont’)  Battery Replacement  Must take less than 1 minute  Charge Time  Charges in 8 hours or less  Power Consumption  Can Run for at least 200 minutes on 1 charge  Removal and attachment of device  Less than 1 minute

P12015: Bill of Materials TypePartManufacturerManufacturer Part #QuantityUnit PriceShipping CostTotal Cost ($) Component 900 MHz 8 dBi Flat Patch Antenna - 4ft SMA Male ConnectoL-com Global ConnectivityHG908P-SM1$54.99$10.95$65.94 Component Precision Haptic 10mm Vibration Motor - 15mm Type model 1Precision Microdrives $7.56 $22.68 Component Precision Haptic 10mm Vibration Motor - 15mm Type model 2Precision Microdrives $7.56 $15.12 ComponentPico Vibe 12mm Vibration Motor - 3.4mm TypePrecision Microdrives $6.48$17.97$24.45 Component 3D Compass and Accelerometer Carrier with Voltage Regulators Pololu Robotics & ElectronicsLSM303DLH1$19.95 ComponentLSM303DLH Tilt Compensated Compass ChipST Micro ElectronicsCOM $6.95$3.86$10.81 ComponentPolymer Lithium Ion Battery mAhSparkfun ElectronicsPRT $11.95 Component16-Bit Ultra-Low-Power MicrocontrollerTexas InstrumentsMSP430F5438A1$12.13 ComponentSmall KeypadFuturlec ElectronicsKEYPADSM1$2.20$4.00$6.20 ComponentSkyeModule M9SkyeTekM9 V ComponentPCB 1$ ComponentIC BATT CHRGR LI+ 1CELLMAXIMMAX1555EZK+TCT-ND2$2.37 $4.74 ComponentIC REG LDO 3.3/ADJ 500MAMAXIMMAX1818EUT33+T2$3.25 $6.50 ComponentIC USB FS SERIAL UARTFTDIFT232RL2$4.50 $9.00 CaseRod, ABS, Beige, 1 In Dia x 1 Ft LGrainger1ZBU61$8.59 Case RIT-1.998$10.00 $19.98 Total Cost:$538.04

Project Timeline

Risk Assessment  MCU Lead Time Taking too long  Motors Vibrating too had for leads  Motors Burning Out  Fails Drop Test  Keypad Lead Time

Questions