The MQ4 is used in gas leak detection equipment in the consumer and industrial markets, this sensor is suitable for detecting CH4 , natural gas , LNG , avoiding exposure to alcohol, kitchen smoke and cigarette smoke . Sensitivity can be adjusted by potentiometer

The Vma449 integrates the Voice Recorder ISD1820 and Playback CI to record a single message up to 20 seconds long. The recorded message is stored in the analog flash memory that keeps the message stored even in the event of a power failure. The module has an integrated microphone to record your message and buttons for recording, partial playback or full reproduction of the message functions.

This AA boost module integrates with TI's TPS61032 auxiliary chip, which is capable of producing 5V 1A with input above 1.8V . The only difference between V1 and V2 is to change the output current from 2A to 1A.

Infrared Obstacle Sensor E18-D80NK

The Vma210 Expansion Board is designed to allow easy access to the interface pins of an Arduino Nano. Each DIO pin or analog pin on the Nano is brought to an appropriate header.

The Arduino WTV020-SD MP3 Module is a voice recording module with 1GB SD Card storage capacity. You can upload WAV and AD4 format files that conform to FAT formatting. It supports 6KHz to 32KHz, being 36KHz for AD4 files and 6-16KHz for voice sampling rate (Audio Sampling).

The Motor Driver de Stepper DRV8825 is a Module Indicated for Control of Stepper Motors of 3D Printers and CNC Equipment, With Current Regulation by Trimpot. The Module Accepts Power between 8.2V and 45V and can supply up to 1.5A per Phase, Supporting Micro Resolution up to 1/32 Steps. It has current and temperature overload protection.

This Module is a Rotary Incremental Encoder. It encodes the shaft rotation signal and outputs the signal by electronic pulse. The Grove –Encoder is a module of the Grove series and has a standard Grove interface. When you need to add a knob to your project, for example a volume knob for a speaker, a selection panel or a digital input, this should be your first choice.