IoT Smart Energy Meter Using ESP8266 & PZEM-004T Module | Voltage & Current Protection

Build a complete IoT Smart Energy Meter Using ESP8266 and PZEM‑004T v3.0 with professional voltage/current protections, automatic relay cut‑off, dual 20×4 I2C LCD pages, and a beautiful violet/dark animated Web UI. Learn wiring, code, thresholds (OV/UV/OC), JSON API, and how to fix LCD “random characters” and stale readings by full‑line rendering and safe NaN handling. Perfect for home and lab monitoring.

What you’ll learn:
✅ Hardware: ESP8266 (NodeMCU), PZEM‑004T v3.0, low‑trigger SSR, 20×4 I2C LCD, page button
✅ Protections: Over Voltage, Under Voltage, Over Current with auto relay cut (manual/auto modes, latching)
✅ Web Dashboard: Live readings, manual controls, thresholds with persistence, animated AC mains indicator
✅ Code Quality: Two‑decimal formatting, units after values, null-safe JSON, robust LCD padding to prevent artifacts
✅Troubleshooting: Clear stale values on mains loss, fix LCD artifacts, avoid NaN in JSON

📌 Code & Circuit Diagram:
ESP8266+LCD Code: https://circuitdiagrams.in/shop/smart...

ESP32+LCD Code:
https://circuitdiagrams.in/shop/smart...

ESP32+OLED Display Cose:
https://circuitdiagrams.in/shop/smart...


Custom Project Enquiry: https://circuitdiagrams.in/custom-iot...

🔧 Components Used:
ESP8266 NodeMCU Board: https://amzn.to/4nOcl8w
DC to DC Step Down Module: https://amzn.to/4425jWm
20x4LCD Display (I2C Module): https://amzn.to/4hWrtiK
PZEM-004T Sensor: https://amzn.to/3WOyiZX
5V Relay Module: https://amzn.to/4qXIBc8
Veroboard: https://amzn.to/487liF6

📸 Gear Used:
Camera: Sony Alpha ZV-E10M2K (16-50mm Power Zoom Lens) [https://amzn.to/4rePypn]
Tripod: DIGITEK DPTR 895VD [https://amzn.to/42y7Cjd]

📌 Chapters
00:00 – Intro & demo
00:37 – Custom Project
00:54 – Components Required
02:58 – Wiring (ESP8266, PZEM‑004T, SSR, LCD)
07:03 – Testing Our System
10:09 – Protections (OV/UV/OC) and auto cut logic
12:50 – High Load Testing
14:03 – Outro

👉 If you enjoy IoT, ESP32, and Arduino projects, don’t forget to Like 👍, Share ↗️, and Subscribe 🔔 to Circuit Diagrams for more tutorials!

📱 Connect & Follow:
🌐 Website: https://www.circuitdiagrams.in
🐙 GitHub: https://github.com/tanmoykundu80
📘 Facebook:   / circuitdiagrams  
📸 Instagram:   / circuitdiagrams  
📌 Pinterest:   / creativescanner8481  
✉️ Email: info@circuitdiagrams.in

📌Hashtags:
#ESP8266 #PZEM004T #SmartIoTEnergyMeter #IoTACEnergyMeter #IoTEnergyMeter #EnergyMeter #IOTProjects #ArduinoIDE #SmartHome #ElectronicsProjects #DIYElectronics #ESP32Projects #overvoltageprotection #undervoltageprotection #overcurrentprotection #voltagecurrentprotectionsystem