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