DFRobot Gravity Expansion Shield and Sensors for Arduino - DFRobot DFR0265 The DFRobot Expansion Shield introduced to the market the famous colour-code for sensors and actuators input and output. The 3-pin format for Signal Voltage and Ground is extremely useful especially when used altogether with the increasingly large range of modules sensors and devices that just simply plug in. The board includes power input for salvaged power supplies or laboratory power supplies and an Xbee socket for multipurpose wireless connectivity such as RF wireless Bluetooth. This version includes a hardware voltage setting via a jumper to allow compatibility with a larger range of components operating at 3.3V like Raspberry pi Due and others. It also includes a Servo external power output with a protective diode enabling you to control a large range of servos from your Arduino. This version also features a convenient switch that lets you program your ATmega328 boards like UNO while you have another serial device connected like an Xbee. Switch it program it and get it back up and running with another switch. You don't need to disassemble your hardware or wiring.