BMP180 Barometric Pressure Sensor altimeter You'll need to grab either

You'll need to grab either 2 or 4 of those

high-speed embedded memories and an extensive range of enhanced peripherals and I/Os

an LED must be used with a resistor to limit or 'choke' the amount of current flowing through the LED - otherwise the LED could burn out

It can control both AC and DC appliances such as Solenoids

with duplex communication speeds of up to 424 kb/s

BMP180 Barometric Pressure Sensor altimeter You'll need to grab eitherMeasuring the absolute pressure of the environment using a digital barometer such as this has some interesting applications. By converting the pressure measured into altitude, you have a reliable sensor for determining the height of your robot, plane or projectile! Using a sensor as capable as the BMP180 you can achieve accuracy of 1m, with noise of only 17cm in ultra high resolution noise. The device will operate at only 0. 3uA meaning low current