Short Wave Radio Communications System for Remote Areas via Raspberry Pi 5

Short Wave Radio Communications System for Remote Areas via Raspberry Pi 5

ISSUE: Areas with patchy or no cell access.
SOLUTION: Use of Short Wave Radio and Raspberry Pi 5

Mobile Raspberry Pi with a shortwave radio
into a computer system to both send and receive data.
Let me break it down so you can see the engineering path:



1. Core Concept

  • The Raspberry Pi acts as the controller/computer.
  • The shortwave radio (HF transceiver or SDR) acts as the communications medium.
  • You create a digital link by converting data (text, packets, JSON, etc.) into audio tones or digital modes that can travel over shortwave frequencies.
  • On the receiving end, the process is reversed—decode tones/digital packets back into data.



2. Hardware Setup

  • Raspberry Pi 5 or Pi 4: Portable computer for encoding/decoding.
  • Shortwave Radio Transceiver: e.g., Yaesu, Icom, or a smaller SDR-based unit.
  • Interface Cable: Audio + PTT (push-to-talk) interface to link Pi → Radio (USB sound card or PiHat like AURSINC SHARI, Signalink, or DIY interface).
  • Antenna: Tuned shortwave antenna (dipole, loop, whip).
  • Optional UPS/Battery: To make it mobile and field-ready.



3. Software Options

You need software to encode and decode digital data for shortwave.
Popular approaches:
  • FLDIGI – Digital modem software (supports modes like PSK31, RTTY, Olivia, etc.).
  • JS8Call – Messaging over HF (optimized for weak signals).
  • Direwolf – TNC for packet radio (AX.25 protocol).
  • Pat Winlink – Email/data over HF using Winlink system.
  • Custom Python scripts – Encode data into audio tones (with libraries like sounddevice or pyaudio), then send/receive via radio.



4. Data Flow (Patch Into Computer System)

  1. Computer System (could be a server, cloud, or local app) generates a message (JSON, text, or command).
  2. Raspberry Pi:
    • Encodes message into digital tones.
    • Keys the radio (PTT) and transmits.
  3. Shortwave Radio sends data over HF.
  4. Receiving Station:
    • Radio receives tones.
    • Raspberry Pi (or PC) decodes tones back to digital data.
    • Data is passed to the system (e.g., REST API, database, dashboard).

This creates a low-bandwidth, long-range data link that works even without the internet.




5. Real-World Use Cases

  • Emergency Communications (EMCOMM) – Send status packets, GPS, or text without the internet.
  • Remote Nodes – Your Empire Node could check in daily with status logs.
  • Mesh/Relay Systems – Multiple Pi + radio stations can form a distributed HF data net.
  • IoT Over HF – Sensors (weather, soil, etc.) in remote areas send updates back via Pi + radio.



6. Limitations

  • Slow data rate – Think 50–300 baud typical, much slower than Wi-Fi or LTE.
  • Legal Requirements – Depending on power/frequency, may need an amateur radio license.
  • Error Handling – HF is noisy, so you’ll want error correction protocols (JS8Call, Olivia, or custom checksum).
 
Flynn's Thoughts on the Use Cases for Shortwave and Raspberry Pi communications for say deep country trucks out of cell range.

  • Use of touch screens for driver feed back.
  • Use of LED screens that might scroll for easy heads up display.
  • Design communication protocol and training video.
  • Use of Python and MSSQL connected to enterprise systems.
  • Use of Speakers and tones so the drivers can clearly understand transitions points or "canned" audio alerts.
 
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