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 ...

The PCF8574_LH library provides a simple interface for controlling the PCF8574 I/O expander using the I2C communication protocol. It allows you to read and write values to the PCF8574's registers, ...

A low-power, compact keypad module based on the STM32L010K4T6 microcontroller. This project includes a 12-button keypad interfaced with a host MCU via I2C or UART, designed to serve as a mini keyboard ...