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.