gpredict-vrn76-bridge

A bridge between Gpredict (or another rigctld-compatible client) and the VR-N76 handheld transceiver. It connects to the radio over Bluetooth Classic SPP/RFCOMM and provides a local rigctld-compatible TCP server.

Requirements

• Linux
• Go 1.20 or later
• Qt 6 Widgets, pkg-config, and a C++17-compatible compiler for the GUI build
• sdptool (optional; used to discover the SPP channel. If unavailable, the bridge tries RFCOMM channel 1.)

Build and test

make build
make test

Run

Start with the graphical interface:

./gpredict-vrn76-bridge -address <MAC_ADDR_OF_VNR76>

The GUI displays connection status and RX/TX frequencies. Click Connect VR-N76 to connect to the radio. The rigctld-compatible TCP server starts when the program starts.

Run without the GUI and attempt to connect to the radio immediately:

./gpredict-vrn76-bridge -headless

Example with explicit settings:

./gpredict-vrn76-bridge \
  -address 38:D2:00:01:2F:3A \
  -host 127.0.0.1 \
  -port 4532 \
  -headless

Options

Option	Default	Description
-address	38:D2:00:01:2F:3A	VR-N76 Bluetooth address
-host	127.0.0.1	TCP server bind address
-port	4532	rigctld-compatible server TCP port
-rx-frequency	437800000	Initial RX frequency in Hz
-tx-frequency	145990000	Initial TX frequency in Hz
-transport	classic-raw	Radio transport; classic-raw and classic use SPP/RFCOMM. BLE is unsupported.
-rfcomm-channel	0	Explicit SPP RFCOMM channel (1–30); 0 attempts SDP discovery
-verbose	false	Enable debug logging
-headless	false	Run without the Qt window and immediately attempt to connect to the radio

For the complete options list, run ./gpredict-vrn76-bridge --help.

Connect Gpredict

By default, the bridge listens only on the local machine at 127.0.0.1:4532. Configure Gpredict (or its rigctld connection) to use that host and port. To make the server reachable from other machines, set -host accordingly and secure access to the TCP port.

Notes

• If sdptool is unavailable or SPP channel discovery fails, the bridge tries channel 1. You can set a channel explicitly with --rfcomm-channel.
• RX and TX frequencies are specified in hertz.