Smart Energy Meter Using ESP32 & Blynk (Blynk Notification)

Description

The ESP32 Smart Energy Meter is an advanced IoT-based electricity monitoring system designed for accurate real-time measurement of voltage, current, power, total energy consumption (kWh), and electricity cost.

This upgraded version solves the common startup instability issue found in many DIY energy meters. A built-in warm-up stabilization filter eliminates garbage readings during boot, ensuring accurate and reliable measurements from the moment the system becomes active. Even with AC mains ON and no load connected, the device maintains near-zero current and power readings.

Components Required

• ESP32 Development Board
• ZMPT101B Voltage Sensor
• ACS712 Current Sensor (30 Amp)
• 16×2 I2C LCD Display (SDA, SCL Enabled)
• 5V DC Adapter or USB supply
• Push Button
• Output AC Socket
• 1.5sqmm AC wires

Blynk Dashboard Settings

Datastreams

You need to make exactly same datastreams like that.

Device Widgets

Assign same widgets for each and every datastreams to sync.

After setting up the datastreams and widgets, upload the code by putting your own blynk and wifi credentials.

Then apply these:

Enter the exact same voltage value by measuring with your multimeter at the “Voltage Value” field.

Enter the exact same current value printed on the load at the “Current Value” field.

Enter the exact same power value printed on the load at the “Power Value” field.

Finally click on the “Calibrate” button for start the calibration.

Note: If the calibration failed or the current and power value is showing zero or unwanted, then just interchange the input plug or wires direction. Make sure the ACS712 gets only phase voltage (not neutral).

*Important Instructions

• Make sure to setup Blynk IoT dashboard properly and extract Blynk Template Name, Template ID, and Blynk Authentication Token from there. If you will not provide all three credentials to the code, Blynk will not connect to the ESP32 and also LCD will not show anything.
• Also make sure to provide correct WiFi Name And Password to the code. If you will not provide the credentials to the code, The system cannot connect with WiFi netowrk and also LCD will not show anything. So the system will be offline.
• Make sure you need to provide your 2.4GHz WiFi network name only. ESP32 cannot work with 5GHz network.

Specificatios

• 80% Real-time RMS AC Voltage Monitoring
• 80% Accurate RMS Current Measurement
• Real Power (Watt) Calculation
• kWh Energy Tracking with EEPROM Storage
• Electricity Cost Calculation (Customizable Tariff)
• Calibration System
• No-Load Accurate Detection
• 16×2 I2C LCD Display with Multi-Page View
• Button Control (Page Switch / Reset / Calibration)
• WiFi-Based IoT Monitoring via Blynk
• Daily Automatic Energy & Cost Notification at 12 AM

Smart IoT Integration

The system integrates seamlessly with the Blynk IoT platform, allowing users to:

• Monitor voltage, current, and power remotely
• Track total energy usage in real time
• View electricity cost updates
• Trigger manual auto calibration from the dashboard
• Receive daily usage and billing notifications automatically

Improved Accuracy & Stability

Unlike traditional DIY energy meters, this version includes:

• Startup warm-up sampling filter
• Smooth signal processing algorithm
• EEPROM-based calibration storage
• Stable readings even during power fluctuations

These enhancements make it suitable for long-term real-world energy monitoring applications.

Applications

• Home Energy Monitoring
• Smart IoT Projects
• Electrical Lab Experiments
• Energy Consumption Analysis
• DIY Smart Meter Development
• Educational Demonstrations

Safety Notice

This device works with AC mains voltage. Proper electrical safety precautions must be followed during installation and operation.