modules

The 5V 700mA isolated switch power supply module is an AC-DC Step-Down converter.

The Lithium battery protection board is a small size board that provides protection against short-circuit, overcharge and overdischarge. The board comes with pre-soldered Nickel strips which makes it a ready-to-use module with 18650 cells.  

The 5V Step-Up Power Module Lithium Battery Charging Protection Board or the Power bank module contains a single chip that has multiple applications.

Due to limited pin resources in a microcontroller/microprocessor, controlling an LCD panel could be tedious. Serial to Parallel adapters such as the I2C serial interface adapter module with PCF8574 chip makes the work easy with just two pins.

The 8x8 Dot Matrix Display Module has a MAX7219 driver IC and an 8x8 LED Matrix.

Dog Barking Sound Module is a good quality sound output module with contact points for triggering the dog sound to the speakers.