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.