# ESP32 Washing Machine Activity Notifier

This project turns an ESP32 into a smart device that monitors a washing machine's activity using vibration and light sensors and sends notifications when a cycle starts and finishes. It also displays the current status on an OLED display.

## Features

- **Vibration Sensing:** Detects machine operation by monitoring vibrations.
- **Light Sensing:** Detects the machine's internal light to determine if the door is open.
- **Status Display:** Shows real-time sensor data and device status on a small OLED display.
- **Notifications:** Sends start and stop notifications to a `ntfy.sh` topic.
- **WiFi Connectivity:** Connects to your local WiFi network.

## Hardware Requirements

- ESP32 development board
- SW-420 vibration sensor module (or similar)
- BH1750 light sensor module
- SSD1306 128x64 OLED display (I2C)
- Breadboard and jumper wires

## Pinout

| Component              | Pin on ESP32 |
| -------------------    | ------------ |
| Vibration Sensor       | GPIO 4       |
| I2C SCL (OLED, BH1750) | GPIO 22      |
| I2C SDA (OLED, BH1750) | GPIO 21      |

### Wiring Diagram

```
+-----------------+      +-----------------+      +-----------------+      +-----------------+
| ESP32 Dev Board |      | Vibration Sensor|      |  BH1750 Sensor  |      |   OLED Display  |
+-----------------+      +-----------------+      +-----------------+      +-----------------+
| 3.3V            |----->| VCC             |----->| VCC             |----->| VCC             |
| GND             |----->| GND             |----->| GND             |----->| GND             |
| GPIO 4          |----->| OUT             |      |                 |      |                 |
|                 |      +-----------------+      |                 |      |                 |
| GPIO 22 (SCL)   |------------------------------>| SCL             |----->| SCL             |
| GPIO 21 (SDA)   |------------------------------>| SDA             |----->| SDA             |
+-----------------+                               +-----------------+      +-----------------+
```

## Setup & Usage

1.  **Install Libraries:**
    - Open the Arduino IDE and go to `Sketch` > `Include Library` > `Manage Libraries...`.
    - Install the following libraries:
        - `Adafruit SSD1306` by Adafruit
        - `Adafruit GFX Library` by Adafruit
        - `BH1750` by Christopher Laws

2.  **Configure the Code:**
    - Copy `secrets_template.h` to a new file named `secrets.h` in the same directory.
    - Open `secrets.h` and populate `SECRET_WIFI_SSID`, `SECRET_WIFI_PASSWORD`, and `SECRET_NTFY_TOPIC` with your WiFi credentials and desired `ntfy.sh` topic.
    - The `secrets.h` file is ignored by git to keep your credentials safe.

3.  **Upload the Code:**
    - Connect your ESP32 board to your computer.
    - Select the correct board and port in the Arduino IDE.
    - Click the upload button.

4.  **Deploy the Device:**
    - Place the vibration sensor on the washing machine where it can detect vibrations from the spin cycle.
    - Place the light sensor inside the machine's drum to detect the internal light.

## Code Explanation

The code is structured as follows:

- **Includes and Definitions:** Includes the necessary libraries for WiFi, I2C devices, and the display. It also defines pins, thresholds, and other constants.
- **`setup()`:** Initializes serial communication, I2C, sensors, the OLED display, and connects to WiFi.
- **`loop()`:** This is the main part of the program.
    - It continuously reads the values from the vibration and light sensors.
    - It implements a non-blocking logic using `millis()` to check if the sensors have been in a certain state (e.g., vibration active or light level high) for a continuous period of 5 seconds.
    - It updates the overall device state (`isDeviceActive`) based on the individual sensor states.
    - If the device state changes, it calls `sendNotification()`.
    - It calls `updateDisplay()` to show the latest data.
- **`sendNotification()`:** Sends a POST request to the configured `ntfy.sh` topic with a message.
- **`updateDisplay()`:** Manages the OLED display. It clears the screen and prints the current status of the sensors and the device. It also implements a scrolling feature to cycle through the displayed information every 2 seconds.