BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//pretalx//talks.caving.dev//nss-convention-2026//talk//BQTNKH
BEGIN:VTIMEZONE
TZID:EST
BEGIN:STANDARD
DTSTART:20001029T030000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10;UNTIL=20061029T070000Z
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
BEGIN:STANDARD
DTSTART:20071104T030000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:20000402T030000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=20060402T080000Z
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20070311T030000
RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
UID:pretalx-nss-convention-2026-BQTNKH@talks.caving.dev
DTSTART;TZID=EST:20260706T154500
DTEND;TZID=EST:20260706T161500
DESCRIPTION:This sensor network\, commissioned in 2024\, measures flood lev
 els at the Snowy River passage\, a mile into the cave. From the online dat
 a we determined that the water level sensor stopped working in March of 20
 25. The remaining network continued to work until May 2 when it quit forwa
 rding messages. In the cave we found that the water sensor microcontroller
  had a dead battery as did the first Longwire terminal. Our team did the p
 lanned annual battery changeout in the cave.\n\nAfterwards we found that t
 he network was broken just a few nodes into the cave. After several months
  we discovered five dead batteries in some of the first nodes. We discover
 ed a dip switch setting on two of them were not back in the low power mode
 . After another month we discovered all 26 batteries had subsequently beco
 me depleted! Entrance to the cave ceased due to a government shutdown\, fo
 llowed by an annual bat hibernation closure. Unable to access the cave\, T
 ed Lappin tested a trial network at home and discovered that a binary bit 
 in the sleep mode configuration settings allowed radios to wake up earlier
  when they lost synchronization with the coordinator node. The radios woul
 d be operating continuously without sleep intervals in a few weeks as thei
 r clocks were adjusting. This caused the costly 3 -month battery lives fro
 m the dip switches being wrong on two nodes. It snowballed to kill all of 
 the batteries as all 26 nodes stayed awake once their sleep cycle modified
  itself.
DTSTAMP:20260826T232451Z
LOCATION:154
SUMMARY:Analysis of a Network Outage in BuecherNet in Fort Stanton Cave\, N
 M - 
URL:https://talks.caving.dev/nss-convention-2026/talk/BQTNKH/
END:VEVENT
END:VCALENDAR