Show HN: A subtly obvious e-paper room air monitor https://ift.tt/ThPJXOq

Show HN: A subtly obvious e-paper room air monitor In the cold season we tend to keep the windows closed. The air gets "stale": humidity often rises above 60 %, which can harm our wellbeing and promote mould. At the same time the CO₂ level in the air increases, which impacts our ability to concentrate. So I built a room air monitor that stays unobtrusive as long as everything is in the green zone, but becomes deliberately noticeable once thresholds are exceeded. For my personal love of statistics I also visualise the measurements in a clear dashboard. https://ift.tt/BVxbaG9 November 18, 2025 at 10:14AM