DIY Real-Time Energy Monitoring Device using ESP32

A comprehensive power consumption monitoring system that measures voltage, current, instantaneous power, and energy consumption in real-time using ESP32 microcontroller and sensor modules.

Table of Contents

• Overview
• Features
• Components Required
• Hardware Setup
• Software Setup
• Circuit Diagram
• Code Explanation
• Assembly Instructions
• Calibration Process
• Usage
• Troubleshooting
• Contributing
• License

Overview

This project creates a smart power consumption monitoring device that can be inserted between any AC appliance and wall socket to measure real-time energy consumption. The device displays voltage, current, instantaneous power, and cumulative energy consumption on an OLED display, cycling through different screens automatically.

Original Tutorial: DIY Real-Time Energy Monitoring Device using ESP32

Features

• Real-time monitoring of voltage, current, and power consumption
• Multi-screen display showing different parameters
• Energy consumption tracking with units calculation
• Automatic screen switching every 5 seconds
• Calibration support for accurate readings
• Compact design with 3D printed enclosure
• Safe isolation up to 4000V with ZMPT101B sensor

Components Required

Component	Quantity	Description
ESP32 WROOM 32D Module	1	Main microcontroller
HI LINK 5V 3W SMPS	1	Power supply module
0.96" 128X64 I2C OLED Display	1	Display unit
ZMPT101B Voltage Sensor	1	AC voltage measurement
ACS712 20A Current Sensor	1	Current measurement
220V AC 3 Pin Socket (Male)	1	Input connection
220V AC 3 Pin Socket (Female)	1	Output connection
3D Printed Casing	1	Protective enclosure

Hardware Setup

Pin Connections

ESP32 Pin	Component	Connection
Pin 34	ZMPT101B	Analog Output
Pin 36 (VP)	ACS712	Analog Output
Pin 21 (SDA)	OLED Display	I2C Data
Pin 22 (SCL)	OLED Display	I2C Clock
5V	All Components	Power Supply
GND	All Components	Ground

Power Supply Connections

• HI-Link SMPS: Connected in parallel with AC Live and Neutral
• ZMPT101B: Input terminals connected in parallel with AC supply
• ACS712: Connected in series with AC Live wire
• All components: Powered by 5V output from HI-Link module

Software Setup

Required Libraries

Install the following libraries through Arduino IDE Library Manager:

1. Adafruit GFX Library
2. Adafruit SSD1306 Library
3. ZMPT101B Library (Custom - download from GitHub)
4. ACS712 Library (Custom - download from GitHub)

Library Installation Steps

1. Open Arduino IDE
2. Go to Tools → Library Manager
3. Search and install Adafruit libraries
4. For custom libraries:
   • Download ZIP files from GitHub repositories
   • Go to Sketch → Include Library → Add .ZIP Library
   • Select downloaded ZIP files

Library Includes

#include "ZMPT101B.h"
#include "ACS712.h"
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

Circuit Diagram

AC Live ──┬─── ZMPT101B Input ─── ESP32 Pin 34
          │
          └─── ACS712 Input ────── ACS712 Output ─── Load
          
AC Neutral ─── ZMPT101B Input ─── Load

HI-Link SMPS:
AC Live/Neutral ─── Input
5V/GND ─── ESP32 & Sensors Power

I2C OLED:
SDA ─── ESP32 Pin 21
SCL ─── ESP32 Pin 22

Code Explanation

Key Functions

• setup(): Initializes sensors, display, and calibration
• loop(): Main execution loop for data acquisition and display
• displayVoltCurrent(): Shows voltage and current readings
• displayInstPower(): Shows instantaneous power consumption
• displayEnergy(): Shows cumulative energy consumption
• displayUnits(): Shows energy units consumed
• CalibCurrent(): Calibrates current sensor zero point
• CalibVoltage(): Calibrates voltage sensor zero point

Display Screens

The device cycles through 4 different screens:

1. Voltage & Current (V and A)
2. Instantaneous Power (W or kW)
3. Energy Consumption (Wh, kWh, etc.)
4. Units Consumed (Based on energy consumption)

Assembly Instructions

1. 3D Print the enclosure using provided STL files
2. Solder all connections according to the circuit diagram
3. Test the circuit on breadboard before final assembly
4. Use heat shrink and insulation tape for safety
5. Fit components into the 3D printed casing
6. Secure all connections and close the enclosure

Calibration Process

Initial Calibration Required

Before first use, calibrate both sensors:

1. Uncomment calibration functions in setup():

   //CalibCurrent();
   //CalibVoltage();

2. Upload code with one calibration function active at a time

3. Ensure no voltage/current is present during calibration

4. Note the zero point values displayed

5. Update zero points in the code:

   voltageSensor.setZeroPoint(2621);  // Update this value
   currentSensor.setZeroPoint(2943);  // Update this value

6. Comment out calibration functions and upload final code

Usage

1. Connect the device between wall socket and appliance
2. Power on - the device will start automatically
3. View readings on the OLED display
4. Screens change automatically every 5 seconds
5. Monitor real-time energy consumption

Reading Interpretation

• Voltage: AC voltage in Volts (V)
• Current: AC current in Amperes (A)
• Power: Instantaneous power in Watts (W) or Kilowatts (kW)
• Energy: Cumulative energy in Wh, kWh, etc.
• Units: Energy consumption units for billing

Troubleshooting

Common Issues

1. Display not working: Check I2C connections and address (0x3C)
2. Incorrect readings: Perform sensor calibration
3. No power: Verify HI-Link SMPS connections
4. Sensor noise: Check grounding and shielding

Threshold Values

The code includes threshold values to filter noise:

• Voltage threshold: 55V (below this, voltage = 0)
• Current threshold: 0.15A (below this, current = 0)

These can be adjusted based on your specific requirements.

Safety Considerations

⚠️ Warning: This project involves mains AC voltage (220V). Take proper precautions:

• Use proper insulation and enclosure
• Test thoroughly before use
• Ensure proper grounding
• Use appropriate fuses and protection
• Follow local electrical codes

Contributing

Feel free to contribute to this project by:

• Reporting bugs
• Suggesting improvements
• Adding new features
• Improving documentation

License

This project is open-source and available under the MIT License.

---

Project Source: CircuitDigest - DIY Real-Time Energy Monitoring Device

Disclaimer: This project is for educational purposes. Use at your own risk and ensure compliance with local electrical regulations.