A website,
hosted on an ESP32.

This entire site runs on a chip with 520 KB of RAM. Every page, every sensor reading, served by a microcontroller. Sign the guestbook or view the source.

Visitors
Uptime
Signal
Memory Used
CPU Temp
SD Card
Temperature
Humidity
Heat Index
eCO₂
VOC
Altitude
Last updated stale
...

Sensors are inside a sealed frame, so readings reflect the enclosure, not the room.

Now Today Total Cost CO2
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Today
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May 10, 2026
Refreshed the photo carousel. The current framed shot now shows the device with the DS3231 and nameplate added over the past couple weeks, with the April 19 mounting-day shot kept as the second slide. New boot video too: sharper, tighter cut, no audio track. Hero image on the GitHub repo got the same treatment.
May 8, 2026
/chronicle got a few quality-of-life updates. Today's in-progress entry shows above the archive, refreshing as the chip writes more of the day. Filter chips slice the archive to just milestones, records, anomalies, busy days, or quiet days. Each entry has a share button, and arrow keys step between days on entry pages. Guestbook translation got smarter too: better source-language detection so casual English no longer trips the translate button, and previously-untranslatable diacritic-less Czech, Polish, and Italian now translate correctly.
May 6, 2026
Chronicle entries now align to the chip's local timezone instead of UTC, so each day's entry covers the chip's actual day from where it's running. The chip also notices when one of its sensors stops working, retires it, and writes a chronicle entry about the loss. Behind the scenes, archive folders moved to a year-grouped layout so the chip can run for decades without slowing down. Firmware 1.4 also drops the boot-time CSV migrations to free flash for future features; pre-1.3 installs need to flash 1.3 first.
May 4, 2026
Added /chronicle: a daily entry the chip writes about itself. Auto-generated from sensor readings, visitors, and weather, archived from today onward. Each midnight the day's snapshot freezes into a permanent entry. Five starter templates pick the right shape for the day (busy, quiet, anomaly, milestone, generic), and there's a permalink for every entry.
May 3, 2026
Snake got its own page. Same game, with two leaderboards now: today's top scores and the all-time top ten. Strong scores cross to all-time on their own. Each top entry has a watch button that plays back the actual game. Past quarters move to a Hall of Fame archive so the leaderboard stays fresh.