Published June 8, 2025

IoT-Based Energy Meter with Extended Functionalities

A smart energy meter with real-time monitoring, IoT control, and extra features like auto lighting, LCD, and USB output.

IntermediateFull instructions providedOver 1 day156

IoT-Based Energy Meter with Extended Functionalities

Things used in this project

Hardware components

DFRobot FireBeetle ESP32 IOT Microcontroller (Supports Wi-Fi & Bluetooth)

SparkFun Low Current Sensor Breakout - ACS712

Texas Instruments 555 Timers Ultra Low Voltage

LDR, 5 Mohm

General Purpose Transistor NPN

Adafruit RGB Backlight LCD - 16x2

Texas Instruments BOOSTXL-DRV8301 DRV8301 3-phase brushless DC Motor Drive BoosterPack

Seeed Studio Grove - 2-Channel SPDT Relay

Rotary potentiometer (generic)

LED (generic)

Capacitor 100 µF

Resistor 10k ohm

Jumper wires (generic)

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Digilent Mastech MS8217 Autorange Digital Multimeter

Solder Wire, Lead Free

Power Supply, Soldering Station

Story

Methodology

This section outlines the approach, tools, and processes used to develop the Smart Home Control System. The project integrates multiple engineering disciplines, including analog electronics, power electronics, embedded systems, and IoT, to create a robust and flexible smart home power management solution. The methodology covers the hardware design, software development, and system integration aspects required to bring this project to life.

1. System Design and Architecture

The project was designed as a modular system with the following core components:

Power Supply Unit (PSU): Converts 220V AC to 5V DC using a rectifier and a switched-mode power supply (SMPS) circuit to power the ESP32 and other components.

Power Supply Unit (PSU): Converts 220V AC to 5V DC using a rectifier and a switched-mode power supply (SMPS) circuit to power the ESP32 and other components.

Power Monitoring and Control: Utilizes a ZMPT101B voltage sensor and a current sensor to measure power consumption.

Power Monitoring and Control: Utilizes a ZMPT101B voltage sensor and a current sensor to measure power consumption.

Automatic Lighting Control: Implements an LDR (Light Dependent Resistor) circuit in a voltage divider configuration connected to the base of an NPN transistor. This configuration allows the light to turn on or off based on ambient brightness levels, acting independently of the ESP32 and relying solely on analog electronic behavior.

Automatic Lighting Control: Implements an LDR (Light Dependent Resistor) circuit in a voltage divider configuration connected to the base of an NPN transistor. This configuration allows the light to turn on or off based on ambient brightness levels, acting independently of the ESP32 and relying solely on analog electronic behavior.

Signal Generation: A 555 timer is configured in astable mode to generate continuous clock pulses, which can be used for timing or triggering purposes in the circuit. This timer operates as a standalone analog module, without any dependency on the microcontroller.

Signal Generation: A 555 timer is configured in astable mode to generate continuous clock pulses, which can be used for timing or triggering purposes in the circuit. This timer operates as a standalone analog module, without any dependency on the microcontroller.

IoT Integration: The ESP32 microcontroller serves as the main control and communication unit, enabling Wi-Fi connectivity and real-time data transmission to the Blynk platform for remote monitoring and control.

IoT Integration: The ESP32 microcontroller serves as the main control and communication unit, enabling Wi-Fi connectivity and real-time data transmission to the Blynk platform for remote monitoring and control.

User Interface and Utilities: An LCD display is included to show system parameters locally, and a USB output is provided for mobile device charging. A potentiometer allows voltage tuning in the booster module, offering adjustable output for various devices.

User Interface and Utilities: An LCD display is included to show system parameters locally, and a USB output is provided for mobile device charging. A potentiometer allows voltage tuning in the booster module, offering adjustable output for various devices.

2. Hardware Development

Power Supply Design: A robust 220V AC to 5V DC converter was developed using a bridge rectifier, filter capacitor, and a switched-mode power supply (SMPS). This unit ensures efficient and safe voltage regulation to operate the ESP32, sensors, and additional modules.

Power Supply Design: A robust 220V AC to 5V DC converter was developed using a bridge rectifier, filter capacitor, and a switched-mode power supply (SMPS). This unit ensures efficient and safe voltage regulation to operate the ESP32, sensors, and additional modules.

Sensor Integration: The ZMPT101B voltage sensor and a current sensor are connected to the analog input pins of the ESP32. These sensors provide real-time measurements of electrical parameters, which are processed and visualized remotely.

Sensor Integration: The ZMPT101B voltage sensor and a current sensor are connected to the analog input pins of the ESP32. These sensors provide real-time measurements of electrical parameters, which are processed and visualized remotely.

Lighting Control: A standalone automatic lighting system was designed using an LDR in a voltage divider configuration with an NPN transistor. This circuit independently controls the lighting based on ambient brightness and operates purely through analog electronics, without relying on the ESP32.

Lighting Control: A standalone automatic lighting system was designed using an LDR in a voltage divider configuration with an NPN transistor. This circuit independently controls the lighting based on ambient brightness and operates purely through analog electronics, without relying on the ESP32.

Clock Signal Generation: A 555 timer IC is configured in astable mode to provide a continuous clock pulse. This circuit functions autonomously and serves as a timing reference or trigger in the system.

Clock Signal Generation: A 555 timer IC is configured in astable mode to provide a continuous clock pulse. This circuit functions autonomously and serves as a timing reference or trigger in the system.

Display and Output Features: An LCD display module is included for local visual feedback of system states. Additionally, a USB port provides convenient charging for mobile devices, drawing power from the main SMPS.

Display and Output Features: An LCD display module is included for local visual feedback of system states. Additionally, a USB port provides convenient charging for mobile devices, drawing power from the main SMPS.

3. Software Development

The software for the ESP32 was developed using the Arduino IDE, incorporating Wi-Fi setup, sensor data acquisition, and communication with the Blynk platform for seamless IoT integration. To ensure efficient and reliable data transfer, MQTT protocols were implemented, reducing latency and enhancing communication stability. The Blynk platform was configured for real-time data visualization, allowing users to monitor and control smart home components remotely through a mobile app, providing a user-friendly interface for managing the entire system.

4. System Integration and Testing

Integration Testing: All modules were tested individually, then assembled onto a unified board. Integration tests were conducted to ensure communication across all parts.

Integration Testing: All modules were tested individually, then assembled onto a unified board. Integration tests were conducted to ensure communication across all parts.

Power Efficiency Testing: The power supply was tested for stable voltage output under different loads, ensuring safe operation of the ESP32 and sensors.

Power Efficiency Testing: The power supply was tested for stable voltage output under different loads, ensuring safe operation of the ESP32 and sensors.

Subfunction Validation: Independent analog circuits like the LDR-based light controller and 555 timer module were verified for standalone operation, ensuring reliability without digital interference.

Subfunction Validation: Independent analog circuits like the LDR-based light controller and 555 timer module were verified for standalone operation, ensuring reliability without digital interference.

Final Assembly: Components were organized and enclosed in a protective case, considering layout, airflow, and insulation for long-term stability and safety.

Final Assembly: Components were organized and enclosed in a protective case, considering layout, airflow, and insulation for long-term stability and safety.

5. Deployment and Evaluation

Field Testing: The system was deployed in a simulated home environment where power usage was monitored, lighting responded to changes in ambient light, and mobile control was tested successfully.

Field Testing: The system was deployed in a simulated home environment where power usage was monitored, lighting responded to changes in ambient light, and mobile control was tested successfully.

User Feedback: Initial users confirmed ease of use, clarity of data visualization, and usefulness of added functions like USB charging and automatic lighting.

User Feedback: Initial users confirmed ease of use, clarity of data visualization, and usefulness of added functions like USB charging and automatic lighting.

6. Challenges and Solutions

Power Noise Management: Filtering capacitors and regulated components minimized ripple and electromagnetic interference.

Power Noise Management: Filtering capacitors and regulated components minimized ripple and electromagnetic interference.

Wi-Fi Stability: Auto-reconnect features were programmed into the ESP32 to maintain reliable cloud communication.

Wi-Fi Stability: Auto-reconnect features were programmed into the ESP32 to maintain reliable cloud communication.

System Isolation: Analog subfunctions were designed to work independently to ensure robustness and minimize microcontroller dependency.

System Isolation: Analog subfunctions were designed to work independently to ensure robustness and minimize microcontroller dependency.

7. Future Improvements

Adding energy analytics using AI for predictive power management.

Adding energy analytics using AI for predictive power management.

Integrating voice control or mobile notifications for enhanced user experience.

Integrating voice control or mobile notifications for enhanced user experience.

Expanding the system to control more devices with advanced power measurement and automation.

Expanding the system to control more devices with advanced power measurement and automation.

Schematics

Code

code

#define BLYNK_TEMPLATE_ID "given from blynk"
#define BLYNK_TEMPLATE_NAME "given to blynk"
#define BLYNK_AUTH_TOKEN "given from blynk"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <EmonLib.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// WiFi credentials
char ssid[] = "name of your wifi";
char pass[] = "password of your wifi";

// Pin configuration
const int ledPin = 27;     // LED 1
const int ledPin2 = 13;    // LED 2
const int voltagePin = 34; // ZMPT101B
const int currentPin = 35; // ACS712

// Calibration values
const float voltageCalibration = 75.0;
const float currentCalibration = 20.0;

// Virtual pin assignments
#define VPIN_LED     V1
#define VPIN_LED2    V4
#define VPIN_CURRENT V2
#define VPIN_VOLTAGE V3

// LCD setup (change I2C address if needed)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Create instances
EnergyMonitor emonVoltage;
EnergyMonitor emonCurrent;
BlynkTimer timer;

void setup() {
  Serial.begin(115200);
  
  // Set LED pins as output
  pinMode(ledPin, OUTPUT);
  pinMode(ledPin2, OUTPUT);

  // Connect to WiFi + Blynk
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

  // Sensor initialization
  emonVoltage.voltage(voltagePin, voltageCalibration, 1.7);
  emonCurrent.current(currentPin, currentCalibration);

  // LCD initialization
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");

  // Read sensors every second
  timer.setInterval(1000L, readSensors);
}

// Handle LED 1 (GPIO 27) from Blynk V1
BLYNK_WRITE(VPIN_LED) {
  int state = param.asInt();
  digitalWrite(ledPin, state);
  Serial.print("LED 1 set to: ");
  Serial.println(state);
}

// Handle LED 2 (GPIO 13) from Blynk V4
BLYNK_WRITE(VPIN_LED2) {
  int state = param.asInt();
  digitalWrite(ledPin2, state);
  Serial.print("LED 2 set to: ");
  Serial.println(state);
}

// Sensor reading + LCD + Blynk update
void readSensors() {
  emonVoltage.calcVI(1000, 2000);
  float Vrms = emonVoltage.Vrms;
  float Irms = emonCurrent.Irms;

  // Filter noise
  if (Vrms < 10) Vrms = 0;
  if (Irms < 0.2) Irms = 0;

  // Debug
  Serial.print("Voltage: ");
  Serial.print(Vrms, 1);
  Serial.print(" V\tCurrent: ");
  Serial.print(Irms, 2);
  Serial.println(" A");

  // Send to Blynk
  Blynk.virtualWrite(VPIN_VOLTAGE, Vrms);
  Blynk.virtualWrite(VPIN_CURRENT, Irms);

  // Display on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("V: ");
  lcd.print(Vrms, 1);
  lcd.print(" V");

  lcd.setCursor(0, 1);
  lcd.print("I: ");
  lcd.print(Irms, 2);
  lcd.print(" A");
}

void loop() {
  Blynk.run();
  timer.run();
}

Credits

gaxil

7 projects • 5 followers

wameedh scientific club

IoT-Based Energy Meter with Extended Functionalities

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Methodology

1. System Design and Architecture

2. Hardware Development

3. Software Development

4. System Integration and Testing

5. Deployment and Evaluation

6. Challenges and Solutions

7. Future Improvements

Custom parts and enclosures

schematics

Schematics

schematics

Code

code

Credits

gaxil

Comments

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IoT-Based Energy Meter with Extended Functionalities

IoT-Based Energy Meter with Extended Functionalities

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Methodology

1. System Design and Architecture

2. Hardware Development

3. Software Development

4. System Integration and Testing

5. Deployment and Evaluation

6. Challenges and Solutions

7. Future Improvements

Custom parts and enclosures

schematics

Schematics

schematics

Code

code

Credits

gaxil

Comments

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