Jeff Burch
Simon Dakermanjian
Mazen Arakji
Jonah Kadish
Derek Smith
Brief Overview
• ECK measures electrical activity of the heart
• 3 electrodes
ECG Data
Circuit Diagram Block One
Block two
Block three
Block Four
Block Five
Block One
• Differential Amplifier• Takes three inputs• Has a gain adjustment
Block Two
• High pass filter• Tried to filter motion
artifact
Block Three
• First LPF• Gain is 1• Cuttoff is 20 Hz
Block Four
• Second LPF• Gain is 2• Cuttoff is the same as
the first LPF
Block Five
• Gain Block of 2
Complete Circuit
Power Issues
• Oscilator 5 V
• Micricontroller 3.6 V
• Transmitter 9 V
• ECG circuit +/- 9V
• Transformer
MicrocontrollerMicrocontroller
• 16 bit RISC processor16 bit RISC processor
• 22 I/O pins22 I/O pins
• 10 bit, 200ksps ADC10 bit, 200ksps ADC
• 4kB program memory4kB program memory
• 256B RAM256B RAM
• USART includedUSART included
Microcontroller ArchitectureMicrocontroller Architecture
• 51 instructions, 7 addressing modes51 instructions, 7 addressing modes• 16 registers, 12 general use16 registers, 12 general use• 6 software configurable power modes6 software configurable power modes• Interrupt-driven I/O, ADC, UARTInterrupt-driven I/O, ADC, UART• Linearly Addressed RAM, Program Linearly Addressed RAM, Program
Memory, and Interrupt VectorsMemory, and Interrupt Vectors• Requires external oscillator for Requires external oscillator for
stability/ADCstability/ADC
Microcontroller LayoutMicrocontroller Layout
Microcontroller InterfaceMicrocontroller Interface
Microcontroller/RFMicrocontroller/RF
9XStream™ 900 MHz Wireless OEM Module9XStream™ 900 MHz Wireless OEM ModuleLong Range
•-110 dBm receiver sensitivity (industry avg. only -93 dBm)
•Up to 1500 ft. (450 m) indoor/urban (900 MHz)
•Up to 7 mi. (11 km) line-of-sight w/ dipole
•Up to 20 mi. (32 km) line-of-sight w/ high gain
Low Power
•150 mA transmit / 50 mA receive current
•Power down current to <26 µA
Very Robust and Sophisticated
•Numerous Communication Options (UART)
Well Priced
•Around $200.00
Communication DetailsCommunication Details
• Perfect Match to Our Requirements
• Stops Us from “Reinventing the Wheel”
• Easily Configured
• Set up for Scalability
Data Packet DetailsData Packet Details
R em ote Sensing U nit 1
Base S tation
LCD
ScrollButton
ScrollButton
Inte
rfa
ce
to
P
C
R em ote Sensing U nit 2
Transceiver ConfigurationTransceiver Configuration
Data FilteringData Filtering
Base Station InterfaceBase Station InterfaceTwo Options
Standard PinsStandard Pins and and
VCC CMOS Levels andVCC CMOS Levels andSCI Interface SCI Interface
Capabilities of the HC11Capabilities of the HC11
BASE STATION
• Current Status– Operating Parts– Tests Performed– Parts Listing
• Future Objectives– Parts to be Added/Replaced– Tests to be Performed
Current Board
schematic
Buffers and Latch
• Buffer– Safeguard for transfer
of bit values
• Latch– Maintains correct
functionality between low order address bits and data bits.
– Also acts as a buffer
EPROM
• 32Kx8 EPROM
• Chip Select Connected to ground
• Pin A15 not terminated
Safety Tests Completed
• Diode Bridge– Incase opposite polarity is applied
• Noise Tests– Before Power Bus– At System Power of HC11(84mV)– Individual Chips
Parts Listing
• Current Components– MC68HC11
– EPROM
– BUFFERS/LATCHES
– 5V REGULATOR
– RESET SWITCH
• Future Components– Xilinx FPGA– SRAM– Bi-directional
Transceiver – LCD
LCD• 20x4• Basic Control Pins
– R/W• 0 = Write, 1 = Read
– E• Enable pin of processor
– RS• Register Select (0 =
Instruction Register, 1 = Data Register)
– D0-D7• Data Pins
Costs
• Current Costs– Micro Controller
(donated)
– Harness: $30
– 3 Transceivers, with 2 RS232 interface: $230
• Future Costs– LCD: $40
Upcoming Plans/Tests
• Test if HC11 can fetch and execute instructions (NO OP NO OP NO OP JMP).
• Implement Xilinx FPGA. Run same basic code.
• Introduce SRAM and use Xilinx for Chip Select. Run same basic code.
• Begin writing useful code.
Basic Chip Select Circuit
A15 A14 D0 D1 D2 D30 0 1 0 0 00 1 0 1 0 01 0 0 0 1 01 1 0 0 0 1
U1
AND2
12
3
U2
AND2
12
3
U3
AND2
12
3
U4
AND2
12
3
U5
NOT
12
U6
NOT
12
Memory Mapping
• Using Pins A15, A14 and A13 for Chip Select
Memory SpaceEPROM FFFF-C000SRAM BFFF-8000
UNUSED 7FFFF-6000UNUSED 5FFF-4000
LCD 3FFF-2000RECEIVER 1FFF-0000
schedual
Future Plans
• Milestone I– Transmitter sends
accurate ECG data
– Writing useful code to process data
• Milestone II– Outputting heart rate to
LCD
Division of Labor
Derek & JeffSensing, digitalizing, and transmitting data
JonahRF CommunicationHelp to link both sides
Simon & MazenReceive, Process, and Output data