Weather board consist of SCP1000 barometric pressure sensor, TEMT6000 ambient light sensor, sensitive SHT15 humidity sensor, directly readable over USB. You can immediately tell what the current pressure, humidity, ambient light level, and temperature is. Graphed over time you can watch weather fronts move in and the rain come down.

Logic level converter by SparkFun is a small device that safely steps down 5V signals to 3.3V and steps up 3.3V to 5V. This level converter also works with 2.8V and 1.8V devices.