navigational aid for a blind individual electrical/ computer engineering team p12015: bob evans...
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Navigational Aid for a Blind Individual
Electrical/ Computer
Engineering Team P12015: Bob EvansJackson LampDavid SachenikDavid Yip
P12016: Curtis BeardAalyia ShaukatDavid TaubmanOliver Wing
Summary
Introduction/Review Power Calculations Battery User Input (Keypad) Microcontroller Navigation Algorithm Schematics Magnetometer RFID Reader/Antenna/Tags Testing Procedures Bill of Materials
P12015: Power Calculations
RFID Reader 1.5796 W*hr
Motors 0.021166667 W*hr
MCU 0.047784 W*hr
Magnetometer 0.0913 W*hr
Keypad 0.083333333 W*hr
*Sum 1.823184 W*hr
*For (10) 20 minute intervals of navigation
Battery is 3.7V, 1000mA*hr, 3.70 W*hr Voltage Output: 3.3V
P12016: Power Calculations
Total Power (mW/hr) Total (mW) Battery Life (%)Total hours of
Life
23.1495 77.165 1.8959 175.8137
236.8721 789.5738 19.3998 17.1823
737.6470 2458.8234 60.4133 5.5175
Battery is 3.7V, 1100mA*hr, 4.01W*hr Voltage Output: 3.3V
*For (10) 20 minute intervals of navigation
Min Usage (mAh) = 23.3833
Min Usage (mWh ) = 77.165
Average (mAh) = 239.2648 Average (mWh) = 789.5738Worst Usage
(mAh) = 745.098Worst Case (mWh)
= 2458.8234
P12016: Battery
Tenergy Li-ion 17500 3.7V 1100mAh 0.71” x 2.09” (Diameter x Height) 1.04 oz. Molex 51021 2-Pin Connector
2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 40
0.5
1
1.5
2
2.5
3
3.5
4
Regulated Output
POK
Battery Voltage [V]
Outp
ut
Volt
age [
V]
Comparison of Voltage Regulation output and POK – Threshold Reached Indicator
User Input (Keypad)
7 Pin Connection Contact rating: 20mA, 24VDC 2.52” L x 2.01” W x 0.28” H 0.26 ounces
Output Pin No.
Symbol
1 ROW 1
2 ROW 2
3 ROW 3
4 ROW 4
5 COL 1
6 COL 2
7 COL 3
Microcontroller Selection
Flow Chart Memory Usage Clock Speeds Approx. Number of Instructions
processes for algorithm
/* performs dijkstras algorithm upon the building graph */"dijkstra(graph *g, int start){ int i,j; bool intree[MAXV]; int distance[MAXV]; int v; int w; int weight; int dist;
for (i=1; i<=g->nvertices; i++) {intree[i] = FALSE; distance[i] = MAXINT; parent[i] = -1; }
distance[start] = 0; v = start;
while (intree[v] == FALSE) { intree[v] = TRUE; for (i=0; i<g->degree[v]; i++) {
w = g->edges[v][i].v; weight = g->edges[v][i].weight; if (distance[w] > (distance[v]+weight)) { distance[w] = distance[v]+weight; parent[w] = v; } }
v = 1; dist = MAXINT; for (i=1; i<=g->nvertices; i++) if ((intree[i] == FALSE) && (dist > distance[i])) { dist = distance[i]; v = i; } }}
Navigation Algorithm
Navigation Algorithm Time Calculation
Type of instruction Cost in cyclesCost in cycles for an N=1000 graph
pre-reserved 0 0“ 0 0“ 0 0“ 0 0“ 0 0“ 0 0“ 0 0
deref, comp, branch 20 20000index, assign 10 10000index, assign 10 10000index, assign 10 10000
increment 6 6000index, assign 10 10
assign 6 6index, comp, branch 20 20000
index, assign 6 6000
Type of instruction Cost in cyclesCost in cycles for an N=1000 graph
index, deref, comp, branch 26 104000index x2, deref x2, assign 30 120000index x2, deref x2, assign 30 120000
index x2, addition, comp, branch 32 128000index x2, addition, comp 32 128000
index, assign 6 24000increment 6 24000
assign 6 6000assign 6 6000
deref, comp, branch 20 80000index x2, comp x2, bool, branch 38 152000
index, assign 10 40000assign 6 24000
increment 6 24000Total: 1062016 cycles
Mapping Data StructuresRFIDTag Representation of an RFID tag. May be implemented as a 64 bit integer.
Tags are stored in an array in FLASH and are referenced with an index value.
StaticNode Basic node in a map graph. Composed of multiple RFIDTags,
destinations, and references to other Nodes using NodeVectors. StaticNodes are stored in an array FLASH and are referenced with an index value.
Elements numTags: The number of tags referenced by this Node. tags: The array of RFIDTag indicies referenced by this Node. numDestinations: The number of destinations associated with this Node. destinations: The array of destinations associated with this Node. numNodes: The number of NodeVectors leading to other nodes
associated with this Node. nodes: The array of NodeVectors leading to other nodes associated with
this Node.
Mapping Data StructuresNode Nodes are used as proxies to the StaticNode structures held in ROM. They
consist of an index value which is used to identify the StaticNode they correspond to as well as a “visited” bit which is used by both the path finding and path following algorithms. An array of these is loaded into memory on system startup in an array which mimics the StaticNode array.
Elements node: The index of the StaticNode this Node represents. visited: The visited status of the node.
NodeVector Represents a link from one node to another. Includes heading and
distance information, which is used to determine edge costs in the navigation algorithm and to direct the user during the path following stage.
Elements node: The index of the Node referenced by this NodeVector. heading: The direction of the referenced node. distance: The distance to the referenced node.
Mapping Data StructuresDestination Structure representing a destination
using an integer identifier and a heading/distance vector.
Elements id: The room number or other
identification code of the Destination. heading: The direction of the Destination
from the host Node. distance: The distance to the Destination
from the host Node.
Memory Requirement Estimate
Tags 300Tag:Node Ratio 2
Avg. Branches:Node 3Avg. Dest:Node 2
Max Branches in Map 8
Structure Struct Size (b) Extra Size (b) Size (b) Instances in RAM Instances in ROM Size in RAM (B) Size in ROM (B)RFIDTag 64 0 64 0 300 0 2400
StaticNode 48 112 160 0 150 0 3000Node 16 0 16 1350 0 2700 0
NodeVector 48 0 48 0 900 0 5400Destination 48 48 0 300 0 1800
Total 2700 12600
MCU Specs
TI MSP430F5438A 16-bit ISA 25 MHz Clock 16 KB SRAM/256 KB FLASH 8 USCI interfaces with support for SPI, I2C,
and other serial protocols 18 Programmable PWM Outputs Extremely low power operation—1.05 mW to
35 mW active mode, 1.1 μW to 300 μW sleep mode
Magnetometer
ST Micro ElectronicsLSM303DLH Tilt Compensated Compass Supply Voltage 3.3V Current in Operating Mode 0.83mA 16-bit data out I2C serial interface
RFID Antenna/Reader/Tags
HperLink Wireless 900 MHz 8 dBi Flat Patch Antenna (HG908P)
Skytek M9 Module Alien Briggs Tag Type ALN-9640 Squiggle Inlay
Block Diagrams/Schematic
USB Interface with Microcontroller USB Transient Suppressor USB Charging Circuit Linear Regulator Keypad RFID Reader PWM (Motors) Magnetometer
Battery & PCB testing
Test Points (TPs) will be placed in the PCB to verify functionality.
Voltage of test points will be measured and compared with their theoretical values.
When the battery is fully charged, all test points should be within +/- 10% of theoretical value.
Example of a TP Table
Test Point (TP) Theoretical Value [V]
Measured Value (When battery is fully charged, falls within +/- 10% of theoretical) [V]
TP1 3.7
TP2 3.3
Keypad Testing
Input Room Numbers/Destinations-Monitor MCU data collection-Feedback from vibrating motors
Powering on/off
MCU Testing
When possible, testing is performed while debugging the MCU.
Navigation algorithm will be tested in the following cases: Known tag ID and destination supplied; path returned in <
1s. Known tag ID and unknown destination supplied; failure
reported in < 1s. Unknown tag ID and known destination supplied; failure
reported in < 1s. Interfaces with other devices will be tested individually
prior to the code being integrated with the main program.
Magnetometer Tests
Correct indication of Northern Direction-With/Without interference(Different areas within building)-Flat surface vs. Tilted at various
angles-Walking motion test
Data interface with microcontroller Power consumption test Heat Dissipation
RFID Reader/Antenna Tests
Antenna Position/Polarity Read distance Optimal reading angles Read Time Power Consumption Test Heat Dissipation
P12015: Bill of MaterialsType Part Manufactuer
Manufacturer Part # Quantity Unit Price Shipping Cost Total Cost ($)
Component900 MHz 8 dBi Flat Patch Antenna - 4ft SMA Male Connecto
L-com Global Connectivity HG908P-SM 1 $54.99 $10.95$65.94
ComponentPrecision Haptic 10mm Vibration Motor - 15mm Type model 1 Precision Microdrives 310-001 3 $7.56 $22.68
ComponentPrecision Haptic 10mm Vibration Motor - 15mm Type model 2 Precision Microdrives 310-002 2 $7.56 $15.12
Component Pico Vibe 12mm Vibration Motor - 3.4mm Type Precision Microdrives 312-101 1 $6.48 $17.97$24.45
Component3D Compass and Accelerometer Carrier with Voltage Regulators
Pololu Robotics & Electronics LSM303DLH 1 $19.95 $19.95
Component LSM303DLH Tilt Compensated Compass Chip ST Micro Electronics COM-09757 1 $6.95 3.86$10.81
Component Polymer Lithium Ion Battery - 1000mAh Sparkfun Electronics PRT-00339 1 $11.95 $11.95
Component 16-Bit Ultra-Low-Power Microcontroller Texas Instruments MSP430F5438A 1 $12.13 $12.13
Component Small Keypad Futurlec Electronics KEYPADSM 1 $2.20 $4.00$6.20
Component SkyeModule M9 SkyeTek M9 V.080527
Component PCB 1 $300.00 $300.00
Component IC BATT CHRGR LI+ 1CELL MAXIMMAX1555EZK+TCT-ND 2 $2.37 $4.74
Component IC REG LDO 3.3/ADJ 500MA MAXIMMAX1818EUT33+T 2 $3.25 $6.50
Component IC USB FS SERIAL UART FTDI FT232RL 2 $4.50 $9.00
Case Rod, ABS, Beige, 1 In Dia x 1 Ft L Grainger 1ZBU6 1 $8.59 $8.59
Case Case RIT - 1.998 $10.00 $19.98Total Cost: $538.04
P12016: Bill of MaterialsPart Manufacturer Mfr P/N Quantity Unit Price
Total Price - All Units
Shipping/Handling
Subtotal
Microcontroller Texas InstrumentsMSP430F5438A 1 N/A N/A
Digital Compass/Accelerometer
Pololu Robotics and Electronics
LSM303DLH 1 $19.95 $19.95
12 Button Keypad (3x4)Futurlec Electronics
KEYPADSM 1 $2.20 $2.20 $4.00 $6.20
Vibrating Motor (#1)Sparkfun Electronics
ROB-08449 4 $4.95 $19.80 $3.56 $23.36
Vibrating Motor (#2)Pololu Robotics and Electronics
1638 4 $3.49 $13.96 $4.95 $18.91
Battery
RFID Reader
Antenna
Elastic Material
IC BATT CHRGR LI+ 1CELL
MAXIMMAX1555EZK+TCT-ND
2 $2.37 $6.50 $0.00 $4.74
IC REG LDO 3.3/ADJ 500MA
MAXIM MAX1818EUT33+T 2 $3.25 $6.50 $0.00 $6.50
IC USB FS SERIAL UART FTDI FT232RL 2 $4.50 $9.00 $0.00 $9.00
Fasteners - Keypad to Housing
McMaster-Carr 4
Fasteners - Housing to Electronics
McMaster-Carr 4
ABS Plus (3D Print Resin)N/A - RIT Provided
N/A - RIT Provided 1.16 $10 $11.60
M2.5 Spacers - 2mm McMaster-Carr 93657A200 4 $0.87 $3.48
M2.5 Spacers - 10mm McMaster-Carr 93657A212 4 $1.07 $4.28
Rocker SwitchSparkfun Electronics
COM-10727 1 $0.50 $0.50
Battery Jumper Wire/Connector
Sparkfun Electronics
PRT-09914 1 $0.95 $0.95