It is a great kit to new users and geeks who have sparkling ideas. You can choose to do soldering in the soldering area.  Access to a BlueSMiRF socket for wireless communication between Arduinos

• 100% SainSmart brand new and high quality.
• Support range: 0-57mm, Supports round, square and irregular objects. It can hold various regular and irregular shapes.
• You can use small flat-nose pliers to hold good objects, convenient for grinding and drilling, convenient and practical.
• Material: Aluminum alloy.

This is a great solution for your prototype, even suitable for all devices that support HDMI and the HDMI Mini Connector. 

• A must buy connector for Raspberry Pi Zero, it can convert one of the ends of your HDMI Cable into a HDMI Mini Connector on Pi zero
• Gold plated plug, sturdy design
• Suitable for all devices that support HDMI and the HDMI Mini Connector

This is a Bluetooth V4.0 Hi-Fi 2x50W Headphone Amplifier

The SainSmart 4-Axis Robotic Arm is designed to be both an amazing toy and an engaging teaching tool.  Modeled to simulate a full-scale palletizing robotic arm, the SainSmart Arm comes with a basic code to test and also allows users to customize their own procedures.  With a range of up to 300 mm (nearly 12”) and 4 axes of freedom, the 3 copper-gear servos allow for incredible flexibility in movement, and can even be precisely controlled using the 9-axis accelerometer gyro controller.  The arm can exactly mimic your own movement!  Unleash that childlike creativity and experience the wonder of robotics today!

Motion Translation

The remote controller and its integrated accelerometer gyroscopes accurately translate the motion of your hand into the movement of the robotic arm.  You’re in full control!

Precise Control

Arm movement is produced by responsive, precision servos.  Motion is snappy and the delay is minimal!

Customizable

The Arduino-compatible microprocessor is fully customizable.  Use the basic code provided to start, and then create your own custom programs!

This is MPPT 10A 12/24V Tracer 1215BN Solar Battery Charge Controller Regulator

• Innovative MPPT technology
• Peak conversion efficiency of 98%
• High tracking efficiency up to 99%
• Several seconds tracking speed
• Die-cast aluminum design and nature cooling
• Temperature compensation
• Diversified load control to meet different requirements
• Four battery type options: Sealed, Gel, Flooded, and USER
• Intelligent lighting and timer control for solar lighting system
• Energy statistics function
• RS485 ports with MODBUS communication protocol
• Optional PC monitoring software and remote meter for real-time monitoring and battery management parameter setting
• Field upgradable firmware

This is MPPT 20A Solar Charge Controller 150V Solar Panel PV input, Tracer 2215BN 

• Innovative MPPT technology
• Peak conversion efficiency of 98%
• High tracking efficiency up to 99%
• Several seconds tracking speed
• Die-cast aluminum design and nature cooling
• Temperature compensation
• Diversified load control to meet different requirements
• Four battery type options: Sealed, Gel, Flooded, and USER
• Intelligent lighting and timer control for solar lighting system
• Energy statistics function
• RS485 ports with MODBUS communication protocol
• Optional PC monitoring software and remote meter for real-time monitoring and battery management

Smart-MPPT series intelligent MPPT solar controller is programmable and especially for solar light system.The charging efficiency is about 20% higher than the traditional PWM controller, which can make the cost of the whole system much lower.

• Innovative Max Power Point Tracking(MPPT) technology, tracking
• efficiency >99%
• Full digital technology, high charge conversion efficiency up to 98%
• 12V/24V system voltage automatic recognition
• 5 stages time can be adjusted
• Can read parameters and running status
• Liquid and GEL battery for selection
• Four stages charge way: MPPT, boost, equalization, float
• Day/Night threshold can adjust automatically
• Remote Unit to configure, with LCD display
• IP67, Strong and durable aluminum case
• Full automatic electronic protect function

MQ-135 module is widely used in air quality control equipments for buildings/offices, are suitable for detecting of NH3,NOx, alcohol, Benzene, smoke,CO2 ,etc

• Wide detecting scope
• Fast response and High sensitivity
• Stable and long life
• Simple drive circuit