~/writing/tags
#go
4 posts
The frozen clock that nobody noticed
A GPS-disciplined NTP server stopped being disciplined, and every monitor stayed green. The giveaway was a freq_ppb value that repeated byte-for-byte across three seconds, which a live servo never does.
130 frames per second, derived from a wire
I built a Go daemon that drives a music visualizer on a Pi, then found out the frame rate wasn't mine to pick. The LED protocol had already decided it. The real work was a latency budget I had to measure before the lights felt locked to the music.
One socket for the whole subnet
A host scanner that opened a raw socket and a goroutine per host fell over on anything bigger than a /24. The rewrite uses one socket and two goroutines no matter how many hosts, with an ARP fast path and an unprivileged fallback.
My weather station lies about the sun
A cheap Ecowitt station reports UV and solar radiation that read high and jump around. The repeater that forwards it to Weather Underground smooths and scales those channels first, and never lets a slow upstream API stall the station.