Ask HN: What have you built with ESPHome, ESP8266 or similar hardware

Hacker News Discussion ↗

Home automation and retrofits

  • Many use ESPHome/ESP8266/ESP32 as glue for Home Assistant: garage doors, gates, blinds, projector/screen, rangehoods, standing desks, coffee makers, kettles, hot tubs, heat pumps, Mitsubishi mini-splits, window curtains, fans, and irrigation systems.
  • Common pattern: intercept existing controls (IR, RF, RS-232, Modbus, relays) instead of replacing whole devices.
  • Some caution about writing to poorly documented Modbus devices and about safety when working near fuel or mains power.

Sensors and environment monitoring

  • Popular projects: CO₂ monitors (often NDIR sensors like SCD30 or Senseair S8), temperature/humidity/pressure sensors, water/heat meters, pond and fish monitoring, fuel/oil tank level, industrial air compressor usage, and solar/energy systems.
  • Some report SCD30 as low‑drift; others experience drift needing continuous recalibration.
  • Concerns raised about ESP32 ADC reliability and noisy PIR motion sensors; 24GHz radar praised as more accurate.
  • Data is typically sent via MQTT, HTTP, or directly to InfluxDB, often logged/visualized on Raspberry Pis or similar.

Displays, e‑ink, and status boards

  • Numerous e‑ink and LED display projects: “newspaper,” calendars, weather dashboards, Todoist boards, wall clocks (including GPS‑backed NTP server), Minecraft player meters, stock tickers, train/transport boards, uptime indicators, and “internet reliability” LED strips.
  • Emphasis on low‑power designs (sleep modes, long battery life) and NTP time sync.
  • Some prefer rolling their own LED control with FastLED; others highlight WLED as a powerful ready‑made option.

Access control and presence

  • Projects include RFID door systems, adjustable bed and casino/arcade/paywall controllers, hot tub and chicken coop doors, and DIY smart locks and doorbells.
  • Bluetooth‑based presence: ESPresense, BLE‑to‑WiFi repeaters, phone/watch beacons, and room‑level localization. Results are mixed; room detection works “ok,” but high‑precision indoor positioning seen as hard, with UWB mentioned as better but not implemented.

Toys, art, and whimsical builds

  • Many playful builds: cat toys (including for blind pets), bubble‑blowing drones, interactive model houses and flats, music boxes with RFID cards, VR body trackers, LED “fire,” wandering‑hour clocks, laser mazes, arcade coin injectors, “on‑air” signs, tomato clocks, and “emergency food buttons.”
  • Thread shows strong enthusiasm for ESP‑class boards as cheap, versatile platforms; ESPHome praised for eliminating much boilerplate, though some still prefer custom firmware or MicroPython for full control.