APRS

Open the APRS tab. HAMORA connects to the APRS-IS network over the internet and asks only for stations near your active operation, or your station: 50, 100 or 250 km around it (100 km to start).

• HAMORA connects as a listener, with your callsign and the ending -HM, so it can’t clash with your own tracker or IGate. No APRS passcode is needed, because HAMORA never sends anything.
• APRS-IS doesn’t send history, so the status says how many stations were heard since you opened it.
• The connection runs only while HAMORA is open, and reconnects by itself. Offline, you see the last stations, marked Cached.

APRS-IS servers are run by volunteers. They see your callsign and the area you asked for: its centre is rounded to about 1 km.

A dark street map fills the screen, centred on you, with range rings, Maidenhead grid squares and dotted trails for moving stations. The streets come from OpenStreetMap through OpenFreeMap: no map account, and the map sees only the area you look at. Offline, the streets stay blank, but your rings, grid and stations still show.

• The buttons beside the map open Nearby and Messages. The settings button picks the source (All · APRS-IS · RF, with counts), the radius and the filters, and shows the connection.
• Type chips filter mobile, fixed, weather, object, digipeater and IGate stations. Advanced filters set how fresh a station must be (15 minutes to 24 hours) and which RF source to show.
• Nearby markers are grouped into numbered circles: tap one to list its stations. Tap a station for its card, and All details for everything it sent.

Station detail

A station shows only what it sent: position, speed, course, altitude, comment, weather, telemetry, its recent track and its packets. The packet path is shown as reported, which isn’t an exact route. Log QSO opens a new QSO with the station’s callsign (without the SSID) and grid; you choose the band and mode, and nothing is saved until you save it.

Advanced APRS is free for everyone.

• Messages. Messages to your exact callsign and SSID appear under “To me”, with a banner and an unread count. Other messages heard are listed separately. They’re kept on your phone only, up to 1,000 messages and 30 days, and you can clear them.
• No replies. HAMORA can’t reply to or acknowledge a message, so the sender won’t get an acknowledgement.
• Tracks of moving stations: up to 24 hours for stations heard on RF.
• Weather (only the values a station sends) and telemetry, named and scaled when the station publishes its definitions.
• Objects and items, with removed ones marked.

With HAMORA Bridge and Dire Wolf, HAMORA also shows the stations your own radio hears. They’re labelled “Heard by your station”, never mixed up with APRS-IS, which is “received over the internet, not by radio”.

What you need

• HAMORA Bridge on a Raspberry Pi, Linux computer or Mac (its installers are being tested).
• A radio tuned to your area’s APRS frequency, such as 144.390 MHz in North America and Malaysia or 144.800 MHz in Europe. Check your region’s band plan.
• The radio’s audio going into the computer: a radio with a built-in USB sound card, or a USB sound card with an audio cable.

Step 1. Install Dire Wolf

Dire Wolf (opens in a new tab) is a free program that turns the radio’s APRS sounds into data. Install it on the Bridge computer:

sudo apt install direwolf

brew install direwolf

Step 2. Copy the receive-only settings

1. Open the Bridge’s setup page and its APRS section. It shows a receive-only Dire Wolf configuration to copy.
2. Save it in your home folder as a text file named direwolf.conf.
3. Change the ADEVICE line to your sound card. On a Raspberry Pi, arecord -l lists them: card 1 is plughw:1,0.

Leave out any lines that make Dire Wolf transmit, such as MYCALL, beacons, digipeating or IGate. Without them, Dire Wolf only listens.

Step 3. Start Dire Wolf

direwolf -c ~/direwolf.conf

When it says it’s ready on port 8001, the Bridge finds it by itself within 30 seconds. Set the radio’s volume so Dire Wolf’s “audio level” shows about 30 to 50.

What you see

• The RF view’s Heard by my station shows stations and packets today and the RF sources that are active, including stations that sent no position.
• Distances are to reported positions. A packet passed on by a digipeater can come from far beyond your radio’s range.
• RF data stays between your Bridge and your phones. It’s never uploaded anywhere.

HAMORA never transmits APRS on RF or APRS-IS: no beacons, positions, messages, replies, acknowledgements, objects, digipeating or IGate. HAMORA Bridge never writes to your TNC.