Exploring Arduino, 2nd Edition

Appendix A: Deciphering Datasheets and Schematics

At the heart of all Arduinos is a microcontroller (or MCU for short). This appendix does not summarize the features of every microcontroller in every Arduino, but it does provide a brief guide to reading and understanding datasheets. Specifically, it examines elements of the Microchip (previously Atmel) ATmega328P (the MCU used in an Arduino Uno). In addition to understanding component datasheets, learning how to read the key parts of a schematic is a critical skill. This appendix investigates the schematic for the Arduino Uno, so that you can get a better idea of how an Arduino actually works.

Reading Datasheets

One of the most important skills that you can develop as an engineer is the ability to read datasheets. Just about any electronic component that you can buy has an associated datasheet that contains information about the technical limits of the part, instructions on how to use its capabilities, and so forth.

Breaking Down a Datasheet

Consider the datasheet for the Microchip/Atmel ATmega328P, for instance. Recall that the ATmega328P is the MCU used in the Arduino Uno and many Arduino clones. To find the datasheet for most parts, you can just perform a Google search. For example, to find the datasheet for the ATmega328P, just search for ATmega328P datasheet on Google and look for the first PDF link from the manufacturer's website (microchip.com in this case). The datasheets for the MCUs used in official Arduino boards ...