Transcript Toroids - SADARS

APRS
Automatic Position Reporting System
By Nicolas - M1HOG
www.M1HOG.com
Introduction
• Disclaimer - Nothing in the talk is warranted as accurate,
optimal or indeed sensible.
• Objectives
• Introduction to APRS and what it can be used for.
• Introduction to the Club project and what it can do.
• Practical - High level talk and equipment walkthrough.
APRS Overview
Automatic Position Reporting System
• Exchange information with other APRS equipped stations
• Call sign
• GPS Position (Altitude / Speed)
• Status Messages
• Comments
• Show Who / What is nearby – Stations repeaters etc.
• Send short Emails via gateways
• Send Messages and Bulletins via APRS network
• Receive or send Weather Reports
• Produce Maps showing stations and messages.
History of APRS
• Based on Packet Radio, developed in the early 80’s
• Small packets of data are transported over the AX.25
protocol using 1200 baud Bell 202 audio frequency-shift
keying(AFSK) on a 2 meter FM Frequency
• KA9Q - Developed software for an early TNC – Terminal
Node controller – Basically a Modem that uses radio
instead of a phone line.
• KA9Q software was later modified to provide a TCP/IP
stack and use a phone line modem. This enabled early
IBM PC’s to access the Internet and was how I first
accessed the Internet.
APRS
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2 meter FM Radio – 144.800
GPS
TNC – Radio Modem – PC required
Tracker/TNC – No PC required
Digipeater
IGate
Radio
• 2 meter FM Radio - 144.800
• Ideally with fixed low level audio input and output
for easy interfacing to a TNC
• Most 2 meter FM radios can be easily adapted
GPS
• Global Positioning System
• Position, speed and altitude
• Typically connected to via a serial lead to a
Tracker…
Terminal Node Controller
• Terminal Node Controller - “Radio Modem”
Traditional TNC Requires a PC
• Tiny Track (TNC + Can send position)
• Open Tracker etc (TNC + Can send position)
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Radios with built in TNC + Tracker
Kenwood D7
Kenwood D700
Yaesu VX-8RA
Tracker
• TNC vs Tracker
• Functions as a “Smart” TNC
Generates the contents of packets
• Typically - GPS plot, Call sign, Messages
With out requiring a PC and separate TNC
• Tiny Track
• Open tracker etc
• May include a display to show packets received
May have various other functions including..
Digipeaters
• A "digipeater" from "digital repeater", digipeaters
receive a packet radio transmission (APRS
packet) briefly store it and then retransmit it on
the same frequency.
• Like voice repeaters, digipeaters are used to
increase the distance a radio packet can travel
• Typically digipeaters enable packets to reach…
IGate
• Sends packets to APRS-IS (Automatic Packet Reporting
System-Internet Service)
• Radio -> TNC -> PC -> Internet connection
• PC Software - APRS4R many others are available
• The APRS data is then be plotted on to maps by various
internet sites…
APRS.FI - M3NQG IGATE
Recent Tracks
G0LGJ
G0LGJ -> M3NQG
M3NQG - Stations Heard
M3NQG - Stations Heard
APRS Review
Automatic Position Reporting System
• Exchange information with other APRS equipped stations
• Call sign
• GPS Position (Altitude / Speed)
• Status Messages
• Comments
• Show Who / What is nearby – Stations repeaters etc.
• Send short Emails via gateways
• Send Messages and Bulletins via APRS network
• Receive or send Weather Reports
• Produce Maps showing stations and messages.
Club Project – Bluetooth TNC
• Based on Open Source hardware and software.
• Draws on Moblinkd, BeRTOS projects
• Provides Tracker, TNC, GPS and iGate functions
APRS Station Comprises
• 2 meter FM Radio – 144.800
• Android App – APRSDroid
• Bluetooth TNC – Our Project!
• Uses Radio to transmit data, not a connection to
the Internet!
Radio
• 2 meter FM Radio - 144.800
• Ideally with fixed low level audio input and output
for easy interfacing to a TNC
• Most 2 meter FM radios can be easily adapted
APRSDroid
APRSDroid
Mobilinkd
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A better user interface for mobile APRS
Low cost — much less expensive than existing
purpose-built APRS gear.
Battery powered and Bluetooth connected.
Excellent performance.
Ready to go with minimal configuration
Mobilinkd TNC
Club Project – Bluetooth TNC
• Simplified version of Mobilinkd design and all
leaded/plug components
• Atmel Micro processor, as used in the Arduino,
and a few supporting parts
• Bluetooth board, to link with APRSDroid etc.
• Can be constructed on Strip/Vero board
• Firmware based on Mobilinkd project
• Configuration and software updates from Android
app
• May be possible to add other features – FT857 –
Freq change prior to TX, power from the radio.
What Next?
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Thoughts and feedback from you
Complete prototype hardware
Test and Demo
Kit and build!
Have more APRS / Packet Stations on the air.
Links
• APRS - http://www.aprs.org/
• APRS.FI – aprs.FI
• BeRTOS - http://www.bertos.org/use/examplesprojects/arduino-aprs
• Mobilinkd – www.mobilinkd.com
• APRSDroid – aprsdroid.org
Thank you !
This presentation is
available at
www.SADARS.org
Nicolas
www.M1HOG.com