Ryan Malloy
6881489bf6
What the Raspberry Pi time-server guides get wrong on a Pi 4, with the measurements. The headline artifact is a four-line pps-gpio patch: PREEMPT_RT force-threads IRQ handlers, and pps-gpio takes its timestamp inside its handler, so the realtime kernel puts a scheduler between the electrical edge and the clock. IRQF_NO_THREAD takes RMS offset from 2468 ns to 199 ns. - kernel/ the patch - dashboard/ live status page (position hidden by default) - docs-site/ the write-up (Astro/Starlight, brass, no tutorial section)
14 lines
503 B
Plaintext
14 lines
503 B
Plaintext
# Copy to .env. Nothing site-specific belongs in the Makefile.
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PI=deploy@gps-ntp.local
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KEY=~/.ssh/id_ed25519
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APPDIR=/opt/gpsntp-dashboard
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# Only needed if you front the dashboard with TLS via `make caddy`.
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DOMAIN=clock.example.internal
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CERT_SRC=$(HOME)/.certs/clock.example.internal
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# hidden (default) | coarse (~11 km) | exact
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# The receiver knows exactly where it is. `hidden` keeps that out of the page —
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# and out of any screenshot you post. Think before you change this.
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GPSNTP_POSITION=hidden
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