Group #13Group #13

West Virginia University - LCSEE West Virginia University - LCSEE Department.Department.

Group Members:

Bahassan, Maher

Rosendale, Matt

Rossetti, Anthony

IntroductionIntroduction

What is a repeater?What is a repeater?

What is DTMF?

User AUser AUser B

Transmitted

Transmitted

146.76 MHz

146.76 MHz

Retransmitted = 146.76

Retransmitted = 146.76Transmitted

Transmitted

146.16 MHz

146.16 MHz

User AUser B

DTMF = Dual Tone Multi Frequency

1209 Hz 1336 Hz 1477 Hz 1633 Hz

697 Hz

770 Hz

852 Hz

941 Hz

1 2 3 A

1 2 3 A

4 5 6 B

1 2 3 A

7 8 9 C

* 0 # D

COR & PTT

SIGNAL SIGNAL

AUDIO

ACTIVE/ENABLE

DUPLEXER

Receiver Transmitter

Inside The Simplest Repeater

AUDIO

ACTIVE/ENABLEReceiver Transmitter

SIGNAL SIGNAL

AUDIO AUDIO

Receiver TransmitterControl Control

Telephone Line

DUPLEXER

Receiver

CONTROLLER

Transmitter

PowerSupply

146.16 146.76

Inside A Real Repeater

Controller RequirementsController Requirements• User changeable defined call sign - ID’s every ten minutesUser changeable defined call sign - ID’s every ten minutes

• Telephone InterfaceTelephone Interface

• Inhibits telephone communication after 3 minutes (exception Inhibits telephone communication after 3 minutes (exception emergency calls)emergency calls)

• Remote accessing of controllerRemote accessing of controller

• Watchdog TimerWatchdog Timer

• Courtesy Tones (Half-Duplex)Courtesy Tones (Half-Duplex)

• RF shieldingRF shielding

• Hang TimeHang Time

• Rapid Transmissions (Kirchunking)Rapid Transmissions (Kirchunking)

Should not have inappropriate Should not have inappropriate interference with transmitter and interference with transmitter and

receiver!!!receiver!!!

•New Technology

•Auto-Patch

•Smart Identification

•Remote Shutdown

•“Kirchunking”

•Optically Coupled

Motorola Microprocessor

RelaysRelays

• Opto/Audio Opto/Audio IsolatorsIsolators

• DTMF DecoderDTMF Decoder

• DTMF EncoderDTMF Encoder

• Tone GeneratorTone Generator

• TelephoneTelephone

•Audio AmplifierAudio Amplifier

•MicroprocessorMicroprocessor

•MemoryMemory

•Transmitter/Transmitter/ReceiverReceiver

12 Volt Source

On/OffControl

Audio In: From Receiver or Telephone

Data Signal In Audio Out: To Transmitter Or Telephone

DAH SelectControl Inputs DIT Select

SPACELED Display and Telephone Control

Telephone Status

POWERSUPPLY

IsolationTone

Generator

DTMFDecoder PIC

DTMFEncoder

MixerAmp Isolation

Isolation

Projected Architecture

Transmitter ActivationTransmitter Activation

1Audio In: From Receiver or Telephone

Data Signal In Audio Out: To Transmitter Or Telephone

IsolationPIC Mixer

Amp Isolation

Start

Is COR HIGH?

NO

Set PTT HIGH

Is COR HIGH?

Yes

Courtesy Tones Start Hang TimeSet PTT LOW

Yes

NO

Identification/Courtesy Identification/Courtesy TonesTones

•555/556 Timer•Tone GeneratorTone Generator•PIC•Voice Chip

“W8CUL /R”

dn

2

Audio Out: To Transmitter Or Telephone

PTT

ToneGenerator

PIC

MixerAmp Isolation

Remote AccessRemote Access– DTMF TonesDTMF Tones

Valid PasswordValid Password

1 = Alternates Transmitter State “Off” - 1 = Alternates Transmitter State “Off” - “On”“On”

0 = Permanent Off0 = Permanent Off

– TelephoneTelephone

Valid Ring CountValid Ring Count

5 = Alternate Transmitter State5 = Alternate Transmitter State4-Sec

2-Sec 75 VRMS @ 20HZ

Audio In: From Receiver or Telephone

Data Signal In 3 Audio Out: To Transmitter Or Telephone

Telephone Status Telephone Control

Isolation

DTMFDecoder PIC

DTMFEncoder

MixerAmp Isolation

Isolation Isolation

Initialize Telephone Call

Possible Band-Pass Filters

Callsign ProgrammingCallsign Programming

DAH SelectControl Inputs DIT Select

SPACEENTER

PIC

Interrupt (PB7:PB4)Begin - End = ENTER

Micro-Controller vs. Micro-Controller vs. Personal ComputerPersonal Computer

• VersatileVersatile

• Low-powerLow-power

• High-SpeedHigh-Speed

• Low-CostLow-Cost

• Wide Operating Temperature RangesWide Operating Temperature Ranges

PIC16F877 System FeaturesPIC16F877 System Features

• 40-Pin CMOS Flash Microcontroller40-Pin CMOS Flash Microcontroller

• Operating Speed: DC-20MHzOperating Speed: DC-20MHz

• 10-bit Multi Channel Analog-to-Digital Converter10-bit Multi Channel Analog-to-Digital Converter

• Interrupt Capabilities = 14 SourcesInterrupt Capabilities = 14 Sources

• Temperature range: -40C to 85CTemperature range: -40C to 85C

• Three Timers (Watch Dog)Three Timers (Watch Dog)

• 256 * 8 Bytes of EEPROM256 * 8 Bytes of EEPROM

• 8K * 14 Words of Flash8K * 14 Words of Flash

• Extensive FeaturesExtensive Features

Controller Front View Control Buttons: DIT - DAH - SPACE - IDENTIFY/ENTER

9-inches

Controller Rear View

9-inches

Cinch ConnectorsFor Interface with WVU's Repeater

3-inches

Power

Identification

Red = TransmitGreen = Receive

Power TelephoneEnable

ON

OFF

ON

OFF

6-inches

6-inches

TelephoneInput

RCV TXR

3-inches

12-VDCConnector

OverviewOverview

• Complete System packageComplete System package– CompatibilityCompatibility

– SimpleSimple

– AffordableAffordable

– FunctionalFunctional

– ReliableReliable

Group Members:

Bahassan, Maher

Rosendale, Matt

Rossetti, Anthony

Marconi

•Special Thanks To:

•Dr. Nutter

•Dr. Palmer