While being highly focused on developing the Kenyan LoRa network I’m also looking at other modes of establishing communications in a disaster situation. Here is one of them that I’m also looking at setting up. It is an amateur radio data transceiver hotspot, capable of handling all digital amateur radio communication modes, including email, SMS, and various digital data protocols. It’s a low-cost, portable system is built around a Baofeng UV-5R handheld radio and an inexpensive Raspberry Pi Zero 2 Wireless computer, connected via an all-in-one radio interface cable. The system operates using the DigiPi amateur radio software, which transforms the setup into a self-contained data hotspot, enabling users to send and receive messages, including SMS and Windlink email via the Pat client, even when entirely offline or without internet access. The device’s potential as a powerful, low-power, and crucial communication tool, particularly in scenarios where conventional infrastructure has failed has caught my attention.
DigiPi is specialised amateur radio software, provided as an SD card image, designed to handle data transmission over Radio Frequency (RF). It is preconfigured as an all-in-one solution for various communication needs. While DigiPi is software, its functionality is typically demonstrated in a budget hardware build that includes: a Raspberry Pi Zero 2 W computer:
- an SD card to load the DigiPi software image
- a Ham radio all-in-one-cable (AIOC)
- a radio transceiver (like the Beofeng UV-5R)
Contents
Functionality and Purpose
DigiPi is software for building a budget-friendly, low-power radio data transceiver hotspot. When loaded onto an SD card and run on a Raspberry Pi computer, it turns a connected radio (such as a Baofeng UV-5R) into a data hotspot. Baofeng UV-5Rs are every common in the Kenyan context being used for everything from farm management to flying operations. A Ham radio license is required (requirements can be obtained from RSK) to own and operate a Baofeng UV-5R.
Key operational characteristics of a DigiPi setup include:
• Standalone Operation: The system is completely portable and can be operated entirely offline, without reliance on the internet or external power (if using a USB battery pack). This makes it suitable for off-grid or post-apocalyptic/prepper scenarios.
• Web Interface: DigiPi provides a self-hosted web client, allowing users to access and manage the system using any Wi-Fi device or web browser connected to the hotspot.
Supported Communication Modes and Services
DigiPi supports many different types of messages and protocols, enabling a variety of communication solutions. The specialized image supports protocols including FT8, JS8Call, and APRS (Automatic Packet Reporting System). These protocols facilitate services such as IM (Instant Messaging), email, and SMS (Short Message Service).
Specific communication features include:
1. APRS Web Chat: DigiPi facilitates APRS packet operations via a web chat service, which can be started through the self-hosted interface.
◦ The web chat interface provides a simple texting interface, making amateur radio operations straightforward.
◦ APRS is described as a global packet radio network, operating on VHF (144.39 in America or 144.8 in Europe).
◦ Users can send messages to other radios or phones, for instance, by setting an alias for a phone number to send an SMS via RF.
2. Email (Pat Windlink Client): DigiPi integrates the Pat Windlink email client software.
◦ Pat transforms the Raspberry Pi into a website that provides a full-blown email interface (including an inbox, outbox, and composition features).
◦ When the Pat Windlink email client is activated, it fires up an AX.25 25 node networking system on VHF frequencies (e.g., 1450 frequency mentioned in one context).
◦ This system allows users to compose and send emails to call signs or actual email addresses over RF, and to connect to Windlink email servers to check messages.
3. Networking Capabilities: Networking features such as APRS Packet Radio network IGate and node services can be configured through the web interface.
Accessibility and Community
The DigiPi software image is essential for developing a standalone or off-grid communication solution.
• Download: The software is available for download at digipi.org.
• Community: The developer, KM6LYW Radio, offers a copy of the DigiPi SD card image to every patron of the channel, leading to thousands of users possessing Digipies.