Raspberry Pi Pico vs Arduino Nano: Which Is Better?

The Raspberry Pi Pico and the Arduino Nano are two of the most popular compact microcontroller boards in the maker world. Both are small, affordable, and capable — but they are built on very different architectures and serve subtly different use cases. Choosing between them comes down to understanding what each does best.

This guide puts the Pico and the Nano head-to-head across every important dimension: processor, memory, GPIO, programming environment, power consumption, cost, and ideal applications. By the end, you will know exactly which board to reach for on your next project.

Overview

Arduino Nano

The Arduino Nano is a compact version of the Arduino Uno, based on the ATmega328P microcontroller (same chip as the Uno) running at 16 MHz with 5V logic. It was introduced in 2008 and has become one of the most-cloned and widely-used Arduino form factors. The Nano measures just 45mm x 18mm and fits directly onto a breadboard, making it ideal for compact prototype circuits.

The newer Arduino Nano Every uses the ATmega4809 (more flash and RAM) and the Nano 33 series adds IoT connectivity (Wi-Fi, Bluetooth, IMU), but the classic Nano with ATmega328P remains extremely popular due to the vast library of compatible code and tutorials.

Raspberry Pi Pico

The Raspberry Pi Pico was released in January 2021 as the first microcontroller board from the Raspberry Pi Foundation, featuring their in-house RP2040 chip. The RP2040 is a dual-core ARM Cortex-M0+ processor running at up to 133 MHz with 264KB of SRAM and 2MB of external flash storage. It operates at 3.3V logic.

The Pico W variant (released 2022) adds Wi-Fi and Bluetooth via the Infineon CYW43439 chip, making it capable of IoT applications.

Processor Comparison

This is where the gap between the two boards is most stark. The ATmega328P in the Arduino Nano is an 8-bit processor running at 16 MHz — a classic, proven architecture that has powered countless projects. It executes simple operations quickly and with extremely predictable timing.

The RP2040 in the Raspberry Pi Pico is a dual-core 32-bit ARM Cortex-M0+ running at up to 133 MHz — roughly 8 times faster clock-for-clock, and with far more capable 32-bit operations. The dual-core architecture allows one core to handle time-critical tasks (like stepper motor control or signal generation) while the other runs application logic.

For most basic projects (reading sensors, controlling LEDs, driving small motors), both processors are more than capable. The Pico's advantage becomes significant in computationally intensive tasks: fast signal processing, running machine learning inference (TinyML), complex mathematical operations, or managing multiple tasks simultaneously.

Memory Comparison

Arduino Nano (ATmega328P)

• Flash: 32KB (program storage)

• SRAM: 2KB (working memory)

• EEPROM: 1KB (persistent storage)

The 2KB of SRAM is a significant constraint. Complex programs that use large arrays, strings, or deep call stacks can run out of SRAM surprisingly quickly. This is one of the most common beginner mistakes with Arduino: 'Why does my program crash or behave strangely? — Out of SRAM.'

Raspberry Pi Pico (RP2040)

• Flash: 2MB (program storage — 64x more than Nano)

• SRAM: 264KB (working memory — 132x more than Nano)

• No EEPROM (emulated in flash)

The Pico's memory advantage is transformative. You can run programs with large lookup tables, store significant amounts of data in RAM, use MicroPython (which has considerable overhead), and develop more complex applications without hitting memory walls.

GPIO and Hardware Interfaces

Arduino Nano GPIO

The Nano offers 22 digital I/O pins (including 6 PWM capable), 8 analog input pins with 10-bit ADC, hardware I2C, hardware SPI, and hardware UART. It runs at 5V logic, which makes it directly compatible with many legacy sensors and modules without level shifting.

Raspberry Pi Pico GPIO

The Pico offers 26 multi-function GPIO pins, 3 of which are ADC-capable (12-bit ADC, higher resolution than Nano's 10-bit), 2 hardware I2C buses, 2 hardware SPI buses, 2 hardware UART ports, 16 PWM channels, and a unique PIO (Programmable I/O) system — 8 state machines that can implement virtually any digital interface protocol in hardware without CPU involvement.

The PIO system is a genuine innovation. It can implement WS2812 LED control, I2S audio, stepper motor drivers, or custom serial protocols at hardware speed, freeing the main CPU cores entirely.

Note: The Pico operates at 3.3V logic. Connecting 5V signals directly to Pico GPIO pins can damage the RP2040. Level shifting is required when interfacing with 5V devices.

Programming Environment

Arduino Nano: C++ with Arduino IDE

The Arduino Nano uses the familiar Arduino C++ environment. Thousands of libraries, millions of tutorials, and decades of community knowledge. If you are following an Arduino tutorial online, the Nano is almost certainly compatible with the code as-written.

Raspberry Pi Pico: MicroPython or C/C++

The Pico supports two main programming approaches. MicroPython is an implementation of Python 3 designed to run on microcontrollers — easier to write, faster to prototype, and accessible to anyone with Python experience. The official MicroPython firmware for the Pico makes it extremely approachable for beginners with Python backgrounds.

Alternatively, the Pico can be programmed in C/C++ using the Pico SDK — more complex but offers maximum performance and access to all hardware features. The Arduino IDE also supports the Pico through the earlephilhower core, allowing Arduino-style C++ code to run on the RP2040.

Power Consumption

The Arduino Nano with ATmega328P draws approximately 15–20mA in active mode at 5V. In deep sleep mode, this drops to under 5 microamps — excellent for battery-powered applications.

The Raspberry Pi Pico draws approximately 25–35mA in active mode at 3.3V. With both cores active and at 133 MHz, this can rise to 90mA. Sleep modes can reduce consumption to very low levels, but the RP2040's sleep architecture is more complex than the AVR's simple sleep modes.

Cost

Both boards are extremely affordable. The official Arduino Nano retails for around $20 USD, though compatible clones cost $2–$4. The Raspberry Pi Pico retails for $4 USD — remarkably cheap for its capabilities. The Pico W (with Wi-Fi) is $6 USD.

Which Should You Choose?

Choose Arduino Nano When:

• You are following existing Arduino tutorials and want maximum code compatibility.

• You are interfacing with 5V sensors and modules and want to avoid level shifting.

• You need the ultra-low-power deep sleep modes of the ATmega328P.

• Your project requires precise, easy-to-implement timing with Arduino's well-tested timing functions.

Choose Raspberry Pi Pico When:

• You need significantly more processing power, memory, or multiple cores.

• You prefer Python programming (use MicroPython on the Pico).

• Your project requires many PWM outputs, multiple hardware serial ports, or custom digital protocols via PIO.

• You want built-in Wi-Fi at an extremely low cost (Pico W at $6 is hard to beat).

Conclusion

The Arduino Nano is a battle-tested classic — familiar, broadly compatible, and perfect for straightforward projects where 5V compatibility and the Arduino ecosystem matter. The Raspberry Pi Pico is a newer, more powerful platform offering dual-core processing, much more memory, innovative PIO hardware, and Python support at a lower cost.

For pure beginners with no Arduino experience, either is a great starting point. For makers who outgrow the Nano's memory and processing limitations, the Pico is a natural upgrade. Many experienced makers keep both in their toolbox.

For more board comparisons and project guides, visit the Circuit Diary Projects page and browse our full blog at the Circuit Diary Blog.