Team Impact
Intelligent Helmet Impact System
Critical Design Review
February 28th, 2008
Amanda Brodbeck
Wei-Chu Liao
Wei-Shen Liao
Chris Mintle
Wei-Chu Liao aka Tom
Chief Technical Officer
Project Statement
Design and prototype an intelligent helmet
that wirelessly transmits real time sensor
data for collection and processing by a base
station.
System Diagram
Analog
SPI
LabVIEW
GUI
SPI
Design Revisions
Modification compare to previous design:
• Temporary accelerometer change
• 30 m indoor wireless transmission range
Hardware Flow Diagram
Hardware
ADXL321
Power
3 Analog
Outputs
8MHz Oscillator
3.3V
5V
USB
8 LEDs
MSP430F169
SPI
UART
A/D
RESET
Temperature
GPIO
JTAG
6 Headers
nRF24L01
SPI
USB
16MHz Oscillator
Outputs
CP2103
Chip
Mini-USB
Connector
PCB
Antenna
Schematic
USB to UART
• Single chip USB to
UART Bridge
(CP2103)
• UART emulator
• Drivers provided
• Mini-USB connector
USB Schematic
Oscillators
•
•
•
•
SMD
Very small profile
8 MHz for MSP430
16 MHz for nRF
Oscillator Schematic
Chris Mintle
Chief Engineering Officer
Accelerometers
• ADXL321
– Operating voltage 3.3V
– Quiescent supply current of
0.49 mA
– Dual axis
– Medium impact (+/- 18g)
• Voltage divider is going to
be needed later on
Accelerometer Schematic
uController
• TI MSP430F169
–
–
–
–
–
–
–
–
Requires 3.3V
600uA Max current draw in active mode
Multi power mode capability
8MHz external crystal oscillator
Port 1 debugging LEDs
Port 3 UART for LabVIEW interface
Port 5 SPI/transceiver communication
Port 6 A/D from accelerometer
uC Schematic
Transceiver
• Nordic nRF24L01
–
–
–
–
–
Requires 3.3V
11.3mA TX /12.3mA RX
2Mbit/s data rate
4 wire SPI interface
2.4 GHz transceiver
• Surface antenna
– Etched on to board
– Range to be tested
Transceiver Schematic
Timing Diagram
Timing Diagram (cont.)
MOSI
MISO
CLK
CSN
CE
Power System
• Voltage regulator (LM1117)
– 5V and 3.3V available on board
• Goal is to have base station powered
through USB
– USB can supply up 100mA
• Helmet will be powered by battery. TBD
Power System Schematic
PCB
Amanda Brodbeck
Chief Strategy Officer
General Software Diagram
Software
MSP430F169
PC
Configuration
LabVIEW
SPI
Sampling
UART
Mini-USB Driver
MSP Configuration
•
•
•
•
•
•
•
Ports
Timing
Power Modes
Sampling
DMA
Master/Slave
Interrupts
SPI
• Interface to transceiver
– Configure transceiver
– Data handling
– Interrupts
Sampling
• A/D timing/sampling
• DMA Handler
• Multiple inputs
UART
• Transmit data to computer for processing
and display
– TX/RX
– Baud rate
Computer Software
• LabVIEW
– Processing data
• Convert signal into meaningful data
– Displaying data on GUI
• Mini USB drivers
Wei-Shen Liao aka Ben
Chief Financial Officer
Division of Labor
Member
Amanda Brodbeck
Tasks and Responsibilities
LabVIEW GUI and UART.
Wei-Chu Liao
SPI, Transceiver, DMA, and USB
interface
Wei-Shen Liao
Sampling, data processing, finances,
and sensor control.
Chris Mintle
Everyone
Schematic, PCB layout, SPI, DMA and
USB interface
Debug, Integration of software,
Documentation
RACI Chart
Amanda
Ben
Chris
Tom
Schematic & PCB
I
A
R
C
SPI & Transceiver
I
C
A
R
LabVIEW Interface
R
C
C
A
Sensors
I
R
C
A
Doc., Debug & Software
Integration
R
R
R
R
R-Responsible C-Consult
A-Accountable I-Inform
Schedule
Milestone I
•
•
•
•
Basic RF link
Sensors communicate with microcontroller
USB communication with computer
Revision 1 of PCB completed and
integrated
• Multi-port sampling
Milestone II
• Basic GUI
• RF data transfer
• Flex PCB schematics and layout ready for
fabrication
• Beginning documentation
Expo
• Working prototype
– Transmit sensor data between base station and
helmet
– Process and display data on LabVIEW GUI
• Documentation completed
– User’s manual
– Technical reference manual
Purchases:
Budget
Part
nRF24L01(Dev. Board)
MSP340F169 (Dev. Board)
MSP340F169 Power supply
nRF24L01 chip
Acclerometer ADXL321 (Dev. Board)
RS232 chip
LM1117(voltage regulator chip)
Oscillator 16MHz
Total Purchases
Expected Purchases for Milestone I:
PCB Rev. 1
1st Order of passive components
Mini-USB port
CP2103 Chip
ADXL321 Chip
Mini-USB cable
Total Expected Purchases for Milestone I
Total Expenses
Fundings:
UROP
EEF
Total Avalible Funds:
Remaining Funds
Experience
Quanity Price
2 $19.95
1 $40.95
1 $3.00
5 $1.60
2 $5.91
2 $0.00
5 $0.00
5 $0.00
Total
$39.90
$40.95
$3.00
$8.00
$11.82
$0.00
$0.00
$0.00
$103.67
1 $104.08
1 $60.00
5 $2.00
5 $2.00
6 $9.00
2 $5.95
$104.08
$60.00
$10.00
$10.00
$54.00
$11.90
$249.98
$353.65
$1,000
$832.00
$1,832
$1,478
Priceless
Questions?