You’ve bought an Arduino starter kit, you’ve followed all the basic guides, but now you’ve hit a stumbling block - you need more bits and bobs to realise your electronics dream. Luckily, if you have an Arduino board, you can simply stack functionality on top in the form of Shields. Shields are specifically designed for the Uno board to be the same shape and pin alignment; you simply plug them on, and you have instant upgrade of functionality.