README.md

MicroPython ESP32 BLE Demo

A lightweight MicroPython demo showing how to:

• Expose a Nordic UART Service (NUS) over BLE
• Control the onboard LED
• Read temperature & humidity from an HDC1080 sensor

Ideal for prototyping sensor-to-mobile IoT applications.

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📋 Prerequisites

• Hardware

  • Wemos ESP32 D1 Mini (or any ESP32 board)
  • HDC1080 temperature & humidity sensor
  • Optional: external red LED on GPIO 2

• Software

  • MicroPython Firmware: esp32-idf4-20210202-v1.14.bin
  • Library HDC1080: hdc1080.py
  • Tool to upload files: ampy or the built-in WebREPL
  • Android: Serial Bluetooth Terminal

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⚙️ Installation

1. Flash MicroPython firmware onto your ESP32:

   esptool.py --port /dev/ttyUSB0 erase_flash
   esptool.py --port /dev/ttyUSB0 write_flash -z 0x1000 esp32-idf4-20210202-v1.14.bin

2. Copy files to the board:

   ampy --port /dev/ttyUSB0 put main.py
   ampy --port /dev/ttyUSB0 put hdc1080.py

3. Reset the ESP32. It will start advertising as ESP32.

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🚀 Usage

1. Open your BLE terminal app and connect to ESP32.

2. Send one of these commands:

   Command	Action
   red_led	Toggle the red LED (GPIO 2)
   read_temp	Read temperature (°C) & get a notification
   read_hum	Read humidity (%) & get a notification

3. You’ll receive responses ending with \n.

4. Watch the onboard LED blink when disconnected, solid when connected.

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🔍 Wiring

ESP32 D1 Mini        HDC1080 Module
---------------       ----------------
GPIO 21 (SDA)   ───>   SDA
GPIO 22 (SCL)   ───>   SCL
GND             ───>   GND
3V3             ───>   VCC

GPIO 2 (optional) ──(LED)─> GND

📄 License

This project is licensed under the MIT License.