Packages Svxlink Gpio

svxlink-gpio

Lets SvxLink key a radio and read squelch through GPIO pins

• Version recorded: 24.02
• Categories: echolink-repeaters
• Upstream: https://www.svxlink.org
• Install after: svxlink-server

What it does

Scripts and configuration that let SvxLink use general-purpose I/O pins -- on a Raspberry Pi or similar -- for push-to-talk, squelch detection and other control lines, instead of a serial port's handshake lines.

Why you would want it

A Pi at a repeater site has GPIO and often no serial port worth using. This is what lets the controller key the transmitter and read a COS line directly from the header, which is both simpler and more reliable than a USB serial adapter at an unattended site.

Before it will work

A board with GPIO, and level shifting or opto-isolation between it and the radio -- 3.3 volt logic connected directly to a radio's control lines is how boards die. Permission to access the GPIO device, which is a group membership on most systems.

How it installs

• apt: svxlink-gpio

Known problems

Direct electrical connection between a computer's GPIO and a transmitter is the part to get right: RF finds ground loops, and an unisolated PTT line at a repeater site is a reliable source of intermittent faults that look like software. Pin numbering conventions differ between board revisions and libraries, which is the commonest configuration error.

Keeping it current

• probe: apt policy
• strategy: apt_upgrade

Where to get help with the software itself

Tobias Blomberg, SM0SVX -- part of the SvxLink project.

Source: catalog/packages/svxlink-gpio.yaml