This semiconductor gas sensor detects the presence of combustible gas and smoke at concentrations from 300 to 10,000 ppm. The sensor's simple analog voltage interface requires only one analog input pin from your microcontroller.
This 4WD wheeled enclsoed robot is equipped with 42mm motors, a motor controller, 10 inch tires, and Spektrum remote control. By default, the robot handles up to 20lbs of additional payload and travels 320 ft/min.
The 4 Power is a shield for Arduino that can control until 4 DC motors and one extra resistive load of your choice. To user it just connect one power supply of until 46V (Max 1A per motor) connecting the terminals Vcc and GND.