1 Why Packet Radio? www.tapr.org • What is the history of packet radio ? • Data packet technology was developed in the mid-1960’s. • Put into practical application in the ARPANET in 1969. • Initiated in 1970, the ALOHANET, based at the University of Hawaii, was the first large-scale packet radio project. • Amateur packet radio began in Montreal, Canada in 1978, the first transmission occurring on May 31st. • This was followed by the Vancouver Amateur Digital Communication Group (VADCG) development of a Terminal Node Controller (TNC) in 1980. 2 Why Packet Radio? (or APRS) www.tapr.org • Sometimes Analog Voice communication can be difficult to understand due to background noise. • Sometimes it takes too long to communicate long names and symbols using voice accurately. • How long would it take to communicate: “Bacitracin Ointment 15mg” in a noisy environment? • Why packet over other modes? Packet has several great advantages over other digital modes: • transparency • error correction • automatic control • Sometimes packet radio can get a signal through when analog modes don’t. 3 What is Packet Radio? Three Basic Components (Experiment 1) 1) Computer 2) Radio 3) TNC (Terminal Node Controller) Option (Experiment 2) Replace TNC with computer software and interface to radio 4 • Choose Radio 1) Verify connection to TNC 2) Verify connection to Sound Card • Choose Interface • TNC – Stand-alone • TNC – Custom dedicated Decision – • Sound Card Interface Options • Choose Computer (We choose Raspberry Pi) • Choose Software • Terminal Tool • Outpost • RMS Express • Etc. 5 • Basic Raspberry Pi Computer Complete • 4 – USB2 Connectors • BCM43438 WiFi and Bluetooth • Low Energy (BLE) on board • Runs on 5 volts through Micro- USB connector • Video – built in HDMI • 40pin extended GPIO • 4 pole stereo output • Software runs on SD Card • Many options available – including color touch screens • Software is a form of LINUX – no cost • Starting cost – about $35 6 My Three Experiments of Operation Using Raspberry Pi Packet Radio or APRS Experiment 1: Using Experiment 2: Using Sound Experiment 3: Using PCB - Standard TNC Card TNC 1. Radio 1. Radio 1. Radio 2. TNC – Heathkit 2. Interface Cable 2. Interface Cable HK-21 3. USB Sound Card 3. PCB-TNC 3. Interface Cable 4. Interface Hardware 4. Software 4. RS232 to 5. Software Raspberry PI Future interface or USB to RS232 Cable 5. Software 7 Check Radio on 145.01 MHz Simplex (Local Packet Frequency) First: Add TNC (Heathkit HK-21) – Because I had one. Development Obtain microphone Pinout on radio Build interface cable Obtain connector information on TNC: (Make Sure between TNC and Radio Input and RS232 See Appendix Components Connect TNC to Laptop Repurposed old 386SX Laptop running Windows 3.1 because it had RS232 Work) Computer ports Used “Terminal” software built in to Use software available Windows 3.1 8 First: Development 1) Hardware Setup 2) Use Terminal Accessory Windows 3.1 4) Turn on TNC Display 6) HELP on REX 5) Connect to REX 3) Set up Serial Port for 7) Stations Heard TNC First Stage – Fully Operational 9 Experiment 1: Using Standard TNC 1. Radio – checked and verified in Slide #9 2. TNC – Heathkit HK-21 – checked and verified in Slide #9 3. Interface Cable – checked and verified in Slide #9 4. Prepare Raspberry Pi – Setup: http://www.qrvtronics.com/CatHAM_Radio/files/M yRaspberryPi.pdf 5. RS232 to Raspberry PI interface: ended up using a USB to RS232 cable (easier to implement). 6. Software: used “gtkterm” for Raspberry Pi 7. See for set-up used: http://www.qrvtronics.com/CatHAM_Radio/files/M yPacketRadio_Experiment_1.pdf 10 Experiment 1: Using Raspberry Pi • Discovered some useful tools built or loadable into the Raspberry Pi 1) VNC software – allows remote control and viewing of the Raspberry Pi over your local network. 2) Gtkterm – terminal for talking to the TNC. (GTKTerm on Raspbian as HyperTerminal alternative.) 3) Adding audio to listen to music on the Raspberry Pi (Ok this has nothing to do with the Experiment 1) 4) Change Screen on Raspberry Pi window 5) Adding a simple screen - display to the Raspberry Pi 11 Working TNC and Raspberry Pi • TNC Advantage: 1) All inclusive box 2) Usually includes a mailbox 3) Easy to set up • TNC Disadvantage: 1) Can be Expensive ($150+) 2) Can use a lot of power 3) Not always compact Three Experiments of Operation Using Raspberry Pi Packet Radio Experiment 1: Using Experiment 2: Using Sound Experiment 3: Using PCB - Standard TNC Card TNC 1. Radio 1. Radio 1. Radio 2. TNC – Heathkit 2. Interface Cable 2. Interface Cable HK-21 3. USB Sound Card 3. PCB-TNC 3. Interface Cable 4. Software 4. Software 4. RS232 to Raspberry PI interface or USB to RS232 Cable 5. Software 13 Experiment 2: Using Sound Card 1. Radio 2. Interface Cable 3. Get audio working on Raspberry Pi 4. USB Sound Card 5. Building a controller/interface adaptor 6. Software 14 Sound Card Operation with Music • Getting the music to work has been a bit of a challenge. • Much of the internet help has been old and outdated. • Sudo apt-get install hamradiomenus was a help. • Completed document for Audio: http://www.qrvtronics.com/CatHAM_Radio/files/MyRaspberryPiSettingUpYo urAudio.pdf 15 Basic Block Diagram Sound Card and Sound Card Interface Replace the TNC The software creates the function that the TNC preforms 16 Working the Experiment • Detailed information: http://www.qrvtronics.com/CatHAM_Radio/files/MyPacketRadio_Exp eriment_2.pdf 17 18 End of Presentation - Questions? • Books • Raspberry Pi 2 Workshop Manual (Haynes) • Raspberry Pi for Dummies (Wiley) • Websites • https://www.raspberrypi.org/learning/soft ware-guide/quickstart/ Books and • https://raspberrypihq.com/ • https://qrvtronics.com/Side_Left_B/MyPA Other Material CKET_Experiments.htm • RS232 Interface ($2.65): https://www.sunsky- Websites online.com/product/default!view.do?subj ect.id=334804 • Raspberry Pi: ($35) • https://www.adafruit.com/product/3775?src=ra spberrypi • OR https://www.newark.com/raspberry-pi/rpi3- modbp/sbc-arm-cortex-a53-1gb- sdram/dp/49AC7637?src=raspberrypi 19 Bibliography • www.tapr.org • M0HPA – for example • http://www.g0hwc.com/raspberry-pi-ham-radio.html • http://f6bvp.org/AX25_BBS_Node_RaspBerry_Pi_install.html • New Raspberry Pi Zero W – Just $10 https://www.adafruit.com/product/3400 20 Appendix HK-21 Pinout Schematic HK-21 Pinout Motorola Microphone Pinout 21 Appendix Puxing Wiring Micro USB Connector 22 Baofeng and Puxing Cable 23.