Original Circuit Diagram: Arduino UNO R3 Now, have a look at our favorite Arduino UNO to find out the AVR chip inside. It is ATMega328P-PU, a low-power version of the traditional ATMega328-PU. The P ...

and an Arduino Uno R3 with an ATmega328P. To do that, he took a bench PSU, added a filter circuit to it, went through the entire ADC range for each board, took a large number of samples at ...

[Rafael] just made a little library that allows you to interface these modules to the Atmega328p-based Arduino UNO in order to gain some memory space. His work was actually based on the great ...

The Arduino Nano and Uno are equipped with very similar processors (the chip that essentially serves as the brain of the board). The Nano features an ATmega328, while the Uno sports an ATmega328P.