Fix alert ring pulse stuck at near-static brightness#105
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now % 2 yields only {0, 1}. Since the ring updates every 60 s and
gcd(60, 2)=2, the parity of now never changes between updates, so
phase was permanently locked at a single value and the ring showed
constant brightness with no visible pulse.
Replace with a 150-second integer window: gcd(60, 150)=30, giving
5 distinct phase values on consecutive per-minute updates so the
cosine brightness ramp is actually traversable. Also removes the
static_cast<std::time_t>(double) truncation footgun.
https://claude.ai/code/session_01Lq2gNbRv9voqav7jsmQMnD
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Summary
Closes #71
The alert pulse was intended to cycle visibly, but the modulo window (
PERIOD_SEC * 100 = 200s) combined with a 60-second ring update rate meant consecutive updates landed only 30% of the cosine apart — making the ring appear as a near-static dim glow during severe weather.The fix uses a 150-second phase window (
gcd(60, 150) = 30), giving 5 distinct, evenly-spread brightness levels per full cosine ramp (~5 minutes total cycle). The pulse is now visibly animated on every per-minute ring update.Changes
src/ring.cpp: replace 2-secondPERIOD_SECmodulo with a 150-secondPHASE_WINDOWchosen to avoid phase lock against the 60-second update cadenceTest plan