Baby Monitor System

Author: Catalin Lucian Patrascu
Email: catalinptr3@gmail.com
Master: SRIC

Introduction

The baby monitoring system provides a way for parents to track the baby's sleeping environment by tracking the light levels, the sound and the temperature. When a certain threshold is reached the system alerts the parents by email. The system also stores the sensor data and generates weekly reports for the parents.

Architecture

Hardware

ESP-WROVER-32 board
Analog sound sensor module
DHT11 temperature and humidity sensor
Cables

Setup

Wiring scheme

Software

Arduino IDE
Blynk cloud desktop and mobile

Code Snippets

2 pins are used for the 2 sensors: 4 and 34

#define DHTPIN 4
#define DHTTYPE DHT11
#define SOUND_ANALOG_PIN 34

Sensor reading and writing

void sendSensorData() {
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  int soundLevel = analogRead(SOUND_ANALOG_PIN);  

  if (isnan(temp) || isnan(hum)) {
    Serial.println("Failed to read from DHT sensor");
    return;
  }

  Serial.printf("Temp: %.1f °C | Humidity: %.1f %% | Sound: %d\n", temp, hum, soundLevel);

  Blynk.virtualWrite(V1, temp);
  Blynk.virtualWrite(V2, hum);
  Blynk.virtualWrite(V3, soundLevel);

Event generation

  if (temp > 21) {
    Blynk.logEvent("high_temperature", "Temperature too high!");
    Serial.println("Temp big enough");
  }
  if (hum < 30) {
    Blynk.logEvent("low_humidity", " Humidity too low!");
  }
  if (soundLevel > 40) {
    Blynk.logEvent("high_noise", "High noise level detected!");
  }
}

App

Blynk is a tool that lets you build and manage your own IoT projects easily. It was used to create custom dashboards on the desktop and mobile app.

With it I added gauges that I dragged onto the screen and use to control or check the devices from anywhere. Blynk connects everything over Wi-Fi, so you get real-time updates and control without needing to mess with complex setups. It was used to alsop send notifications over email and in-app

Functionalities

In this project, the ESP32 collects data from a DHT11 sensor to measure temperature and humidity, and from a sound sensor to check noise levels. It sends that data to the Blynk app, where you can see live values on your phone using gauges and other widgets.

You can also set up notifications — for example, get an email if the temperature gets too high or if there’s too much noise. Everything works over Wi-Fi, so you can monitor things remotely without being near the device.