Is It Dry Yet?

Original Article ↗ Hacker News Discussion ↗

Fed up with “dumb” laundry appliances, several commenters describe using smart plugs, Home Assistant, vibration or temperature sensors, and Tasmota-flashed devices to detect when washers and dryers finish and send phone notifications, all while keeping control local and avoiding cloud lock‑in. Others weigh the pros and cons of buying built‑in “smart” machines versus retrofitting dumb ones, raising concerns about reliability, inductive load safety, cost, and the hassle of complex home‑automation setups. A sizable side thread contrasts automated drying with low‑tech options like clotheslines and indoor racks, highlighting how climate, humidity, housing conditions, and convenience shape what actually works in practice.

Detecting When Laundry Is Done

  • Popular approach: plug dryer/washer into a smart plug that reports power usage to Home Assistant; trigger a “finished” notification when draw drops below a small threshold for N minutes.
  • Variants discussed: countdown timers that reset while power > X W, excluding short heater cycles; tracking an “operational state” entity (Off / Drying / Finished).
  • Alternatives when power monitoring is impractical or risky:
    • Vibration sensors (Zigbee, YoLink, etc.) stuck on machine; automations fire when vibration starts/stops.
    • Temperature sensor on exhaust duct; alert when temp falls below a threshold for some time.
    • Old hacks: using a laptop’s accelerometer on top of the dryer; or just a mechanical kitchen timer.

Smart Appliances vs DIY Automation

  • Some prefer buying smart washers/dryers that send notifications, noting price deltas of ~€100 over “dumb” units.
  • Others dislike built-in “smart” features: unreliable moisture sensors, incomplete drying, or features locked behind apps.
  • Home Assistant is praised for flexibility (including Apprise notifications), but criticized as complex, YAML-heavy, and poorly documented for simple tasks.
  • Some argue much of consumer IoT is superficial, cloud-tied, and not designed for serious local automation.

Dryers vs Air-Drying

  • Several argue the “smart” solution is to avoid dryers: lines, racks, indoor pulley systems, balconies; lower wear on clothes and no electricity.
  • Counterpoints: hanging is tedious, can cause stiff towels and wrinkles, and is hard in small, damp, or very humid homes (mold, musty smell).
  • Debate over climate:
    • Some say clothes dry fine indoors or even at –20°C; cold air is often dry and sublimation works.
    • Others in cold-and-humid regions report clothes never fully dry and smell bad.
    • Ventless vs vented dryers and home ventilation strongly affect indoor humidity.

Electrical & Safety Considerations

  • Concern about using generic smart plugs with inductive loads; risk of relay damage if switching motors on/off.
  • Some note that if the smart plug never interrupts power (only measures), the risk is lower.
  • Suggestions: high-power smart switches (e.g., geyser-rated), external relays, or avoiding clamps on 240V two-leg circuits unless measuring a single conductor.

Miscellaneous Reactions

  • Some are satisfied with built-in buzzers/jingles; others can’t hear them from basements/garages or while wearing headphones.
  • A subset sees all this as overkill versus a phone/physical timer, while others value the project as fun and educational.
  • The generated cover art drew both praise (aesthetic effort) and critique (large file size, obvious AI style, perceived low effort).