An Arduino UNO has a limited number of GPIO pins - but what if it is not enough? The GPIO expansion shield specifically designed for Arduino UNO-type boards. This shield greatly expands the GPIO resources to 36 pins in total, including 14 digital pins, 6 analog pins and 16 I2C pins. In addition digital and analog pins include the DFRobot "Gravity" interface, giving you in-line power and ground pins and saving you having to connect millions of jumper wires for a single sensor.
Arduino Digital Pins: 14, D0 - D13
Arduino Analog Pins: 6, A0 ~ A5
I2C to GPIO Digital Pins: 16, P0.0 ~ P0.7; P1.0 ~ P1.7
I2C Port: 1
UART Port: 1
Power Supply: 5 VDC / External Power Supply (jump cap switch)