knockSensor

This project demonstrates how to use an ESP32 to read data from a DHT11 temperature and humidity sensor, and an SW-18010P knocking sensor. The data is sent to a web server over WiFi and to a BLE characteristic.

Table of Contents

• Hardware
• Libraries
• Setup
• Usage
• Code Overview

Hardware

• ESP32 Dev Board
• DHT11 Temperature & Humidity Sensor
• SW-18010P Knocking Sensor

Libraries

This project uses the following libraries:

• DHT Sensor Library
• ArduinoBLE Library
• WiFi
• ESPAsyncWebServer

Setup

1. Connect the DHT11 sensor:
   • Data pin to GPIO 13
   • Power and Ground pins to 3.3V and GND
2. Connect the SW-18010P knocking sensor:
   • Data pin to GPIO 16
   • Power and Ground pins to 3.3V and GND
3. Install the required libraries in your Arduino IDE:
   • DHT Sensor Library
   • ArduinoBLE Library
   • WiFi
   • ESPAsyncWebServer
4. Configure WiFi credentials in the code:
   • const char* ssid = "your_SSID";
   • const char* password = "your_PASSWORD";

Usage

• Upload the code to your ESP32 board.
• Open the Serial Monitor to check the connection status and sensor readings.
• Connect to the ESP32 over WiFi and navigate to the IP address shown in the Serial Monitor to see the web page displaying sensor data.
• Use a BLE client to connect to the ESP32 and read the sensor data via the BLE characteristic.

Code Overview

Libraries and Definitions

#include "DHT.h" #include <BLEDevice.h> #include <BLEServer.h> #include <BLEUtils.h> #include <WiFi.h> #include <WebServer.h>

• DHT.h: For reading temperature and humidity data from the DHT11 sensor.
• BLEDevice.h, BLEServer.h, BLEUtils.h: For BLE communication.
• WiFi.h: To connect to WiFi.
• WebServer.h: To create a web server for displaying sensor data.

Global Variables

WiFi credentials:

const char* ssid = "your_SSID"; const char* password = "your_PASSWORD";

Sensor values:

String temperature = "N/A"; String humidity = "N/A"; String knocking = "Nikdo neklepe";

Functions

• getTimeAgo(): Returns the time elapsed since the last data update.
• handleRoot(): Serves the HTML page displaying sensor data.
• setup(): Initializes the sensors, WiFi, web server, and BLE.
• loop(): Reads sensor data, updates the BLE characteristic, and handles web server requests.

Additional Notes

• The web server refreshes every second to display updated sensor data.
• BLE characteristic updates with the latest sensor values every second.