Open hardware would not be where it is today without Arduino and Raspberry Pi boards. Compact, powerful, and mostly open source, both Arduinos and Rasp Pis offer a level of functionality in a small footprint that simply did not exist a decade ago. To casual observers, the two may seem interchangeable, but when the time comes to choose which to develop a project around, your choice can make the difference between success and failure. While some overlap exists, at the very least matching the hardware to the project and your intentions can determine how complicated your device can become.

Many do-it-yourselfers make this choice on the advice of friends – which is fine, so long as their friends' knowledge is as extensive as it sounds. The problem is, people tend to advocate what they know. For this reason, researching the differences between Arduinos and Rasp Pis is generally the safer and most efficient approach. What follows is a general overview of the capacity of both and the purposes for which they are most suited.

SBCs vs. Microcontrollers

While both Arduinos and Rasp Pis are sometimes described as nano computers, only Rasp Pis are computers in the same sense as a laptop or a workstation. Technically speaking, Rasp Pis are single-board computers (SBCs) [1], offering basic computer functionality on a single circuit board. Just what that functionality is has shifted since the first Rasp Pi was released in 2009 and still depends partly on the model. Currently, the fastest Rasp Pi has a 1.4GHz processor, slightly less than that of entry-level Chromebooks, but many times faster than any Arduino. Depending on the model, a Rasp Pi's peripherals can include an Ethernet port, aluminum heat sinks, and LAN and Bluetooth support. Memory is either on-board or provided by an online microSD card. Additional functionality can be added using Hardware Attached on Top (HATs) [2] for purposes like high-resolution displays and sound cards – a development that technically plays fast and loose with the definition of an SBC.

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