If, however, they don't seem to be a great fit for your needs, there are several other small Arduino boards you can use instead, including the Micro (18 by 48 mm), MKR Zero (25 x 61.5 mm) and MKR ...

However, the Arduino can achieve several things that a Raspberry Pi can't. Arduino and Raspberry Pi models are both affordable, and there are many Raspberry Pi projects that won't break the bank .