D Trend – Learn Electronics, Tech & Innovation

  🎯 Build Your Own RFID Attendance System Using Arduino + ESP32 + Google Sheets 📅 By Dinesh | Tech DIY Projects | May 2025     🚀 Introduction Have you ever wanted to build a smart attendance system that logs student or staff attendance directly into Google Sheets in real time? In this tutorial, I’ll show you how I created a WiFi-connected RFID attendance system using: ✅ Arduino UNO (for RFID + DFPlayer) ✅ ESP32 (for WiFi + Google Sheet logging) ✅ Google Apps Script (to act as a cloud database) Let’s dive in! 🧠 Project Concept Here’s how the system works: User scans an RFID card . Arduino detects the card, plays a welcome sound using DFPlayer, and sends the name to ESP32. ESP32 receives the name via serial and logs it to a Google Sheet using a webhook . Done! The name and timestamp are saved in the cloud. 🧰 Components Used Component Quantity Arduino UNO 1 ESP32 (DevKit v1) 1 MFRC522 RFID Reader 1 RFID Tags/Cards 2+ DFPlayer Min...

  🌞 DIY Arduino Solar Tracker with Motor Control – Complete Guide 🔧 Overview: This project uses Light Dependent Resistors (LDRs) to track the sun's position and adjust the orientation of a solar panel using two servo motors . Additionally, based on the sunlight intensity, it controls a motor using two buttons – ideal for automating a solar-powered device like a water pump. 🧰 Components Required: Component Quantity Description Arduino Uno 1 Microcontroller board Servo Motor (SG90/MG90) 2 For horizontal and vertical rotation LDR (Light Sensor) 5 For detecting sunlight intensity and direction 10kΩ Resistors 5 Pull-down resistors for each LDR Push Buttons 2 For controlling motor direction DC Motor 1 Can be used for pumping or rotation purposes NPN Transistor (optional) 1 For driving higher power motors Diode (1N4007) 1 For back EMF protection Power Supply (9V/12V) 1 To power the motor       Breadboard + Jumper Wires            ...