ESP32 Portable IoT Weather Station

A portable, battery-friendly weather station built with ESP32 and DHT22, running as a Wi-Fi Access Point with a modern web interface. No internet required — connect directly to the ESP32 AP and view live data.

Screenshot

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✨ Features

• Access Point Web Server
  • Runs as standalone AP (default SSID: ESP32-Weather, password: weather123)
  • AP auto-restarts if it drops (AP Guard)
• Sensor
  • DHT22 connected to GPIO 4 (configurable)
  • Reads every 10 seconds
  • Computes Heat Index (Steadman)
• Modern Web UI
  • Responsive design (mobile + desktop)
  • Large centered KPIs for Temperature, Humidity, Heat Index
  • System stats: Chip, Cores, Revision, CPU MHz, Flash, Heap (in KB)
  • Sensor status indicator (ONLINE / OFFLINE)
  • Built-in Serial Monitor view with Clear button
• Robustness
  • Hardware watchdog using ESP-IDF v5 API
  • Non-blocking loop (millis()-based timers, minimal delay)
  • Periodic AP keep-alive

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🛠 Hardware

• Board: ESP32 (tested on LOLIN32 v1.0.0)
• Sensor: DHT22
• Connections:
  • DHT22 VCC → 3.3V
  • DHT22 GND → GND
  • DHT22 DATA → GPIO 4 (default)

Optional: Li-Ion/Li-Po battery (many LOLIN boards support charging directly).

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🚀 Build & Upload

1. Clone this repo or download the .ino sketch.
2. Open in Arduino IDE.
3. Select Board: LOLIN32 or ESP32 Dev Module.
4. Select correct Port.
5. Upload.
   (Press BOOT during upload if required by your board.)
6. Open Serial Monitor (115200 baud) to see simple DHT22 status logs.

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🌐 Usage

1. Connect to Wi-Fi AP:
   • SSID: ESP32-Weather
   • Password: weather123
2. Open browser at http://192.168.4.1/.
3. UI will display:
   • Temperature, Humidity, Heat Index (large centered cards)
   • System stats (chip, cores, revision, flash, heap total/free/used in KB)
   • Sensor status pill
   • Serial Monitor logs with Clear button