Smart Energy Meter Telemetry System

A real-time IoT telemetry platform for a cost-effective 3-phase smart energy meter, built using embedded firmware, custom binary communication protocols, Apache Kafka, and a Flutter dashboard. The system continuously measures electrical parameters, streams telemetry with low overhead, and provides live monitoring with persistent storage.

---

Features

• Real-time monitoring of:

  • Voltage (RMS)
  • Current (RMS)
  • Power
  • Energy

• Custom binary UART communication between ATmega328P and ESP8266

• Custom 20-byte binary TCP protocol for efficient telemetry transmission

• Apache Kafka–based event-driven streaming pipeline

• Live Flutter dashboard via WebSockets

• MongoDB persistence for historical analytics

• NTP-based timestamp synchronization

• Modular and scalable architecture

---

Architecture

                +-------------------------+
                |     Smart Energy Meter  |
                |      (ATmega328P)       |
                +-------------------------+
                           |
                           | Binary UART
                           |
                           ▼
                +-------------------------+
                |        ESP8266          |
                | Wi-Fi + TCP Client      |
                +-------------------------+
                           |
                 Custom Binary TCP
                           |
                           ▼
                +-------------------------+
                |    Node.js TCP Server   |
                |   Binary Packet Parser  |
                +-------------------------+
                           |
                           ▼
                    Apache Kafka
                  meter-readings topic
               ┌────────────┴────────────┐
               ▼                         ▼
        MongoDB Consumer         WebSocket Consumer
               │                         │
               ▼                         ▼
      Historical Storage        Flutter Dashboard

---

Technology Stack

Embedded

• ATmega328P
• ESP8266
• Arduino C++
• SoftwareSerial
• SerialTransfer

Backend

• Node.js
• Apache Kafka
• KafkaJS
• TCP Sockets

Database

• MongoDB

Frontend

• Flutter
• WebSockets

---

Telemetry Flow

1. ATmega328P samples voltage and current.

2. RMS voltage, RMS current, power, and cumulative energy are calculated.

3. Measurements are packaged into a compact binary packet.

4. Packet is transmitted to ESP8266 over UART.

5. ESP8266 appends timestamp and meter ID.

6. ESP8266 sends a 20-byte binary packet over TCP.

7. Node.js parses the packet and publishes telemetry to Kafka.

8. Kafka streams data to:

   • MongoDB consumer (storage)
   • WebSocket consumer (live dashboard)

---

Custom Binary TCP Protocol

Each telemetry packet is 20 bytes.

Offset	Size	Field
0	4 bytes	Timestamp
4	4 bytes	Meter ID
8	2 bytes	Voltage
10	2 bytes	Current
12	4 bytes	Power
16	4 bytes	Energy

Compared to an equivalent JSON message, the binary protocol significantly reduces payload size, making it suitable for resource-constrained IoT devices and real-time telemetry.

---

Project Highlights

• Developed firmware for a 3-phase smart energy meter
• Implemented custom UART and TCP binary protocols
• Built a Kafka-based event-driven telemetry pipeline
• Enabled real-time Flutter dashboards
• Designed for low-overhead telemetry transmission
• Persistent storage using MongoDB
• Timestamp synchronization using NTP

---

Repository Structure

.
├── firmware/
│   ├── atmega328p/
│   └── esp8266/
│
├── backend/
│   ├── tcp-server/
│   ├── kafka-consumer-websocket/
│   └── kafka-consumer-mongodb/
│
├── flutter_app/
│
└── README.md

---

Future Improvements

• TLS-secured TCP communication
• Automatic device registration
• OTA firmware updates
• Packet checksum and CRC validation
• MQTT support
• Grafana dashboards
• Alerting for abnormal power consumption
• Multi-meter fleet management

---

Key Concepts Demonstrated

• Embedded Systems
• IoT
• Binary Protocol Design
• TCP Networking
• Event-Driven Architecture
• Apache Kafka
• Real-Time Streaming
• WebSockets
• Flutter
• MongoDB
• Distributed Systems

This README clearly communicates both what the project does and why its architecture is technically interesting, making it suitable for GitHub and for recruiters reviewing your portfolio.