Plug the RFID module into the breadboard with enough space around it. Connect the VCC pin to the Arduino's 3.3V (not 5V), and GND to the ground rail. For the data connections, wire SDA to Pin 10, SCK ...

A simple IoT-based system that monitors room temperature in real-time using a NodeMCU and temperature sensor. Data is sent to a server via Wi-Fi, stored in a MySQL database, and displayed on a web ...