Source: https://mokxi.com/learn/arduino-uno-vs-esp32-vs-pico Updated: 2026-09-27 Learn # Arduino Uno, ESP32 or Raspberry Pi Pico: which to start with Written by the Mokxi team, updated September 27, 2026 Sign up free or see every lesson - 192 parts on the bench - 25 boards running now - 1.00x real time, on every board Click to open it in the editor The same blink program every board ships, on the ESP32: its own LED on GPIO 2 and a wired LED on GPIO 4. These three boards cover most of what beginners and students buy, and each is the right first board for someone. The short answer: start with an Uno if you want the gentlest path and the most tutorials, an ESP32 if your project needs WiFi, and a Pico if you want the most speed and memory for the least money. The rest of this page is the reasoning, so you can decide for your own project. The circuit above is a classic ESP32 DevKit running blink, and the buttons further down open the same program on an Uno and on a Pico. It is worth doing: the three sketches are the same five lines, and the only differences are the pin numbers and the voltage the LED sees. That is the first thing to know about all three. They are programmed the same way in the Arduino environment, so what you learn on one carries over. ## The three boards in numbers Arduino Uno R3: an 8-bit ATmega328P at 16 MHz with 32 KB of flash and 2 KB of RAM. 5 V logic, 14 digital pins of which 6 do PWM, 6 analog inputs with a 10-bit converter, one UART, and hardware I2C and SPI. No wireless. ESP32 (the classic ESP32-WROOM on a DevKit board): a dual-core 32-bit processor at up to 240 MHz with about 520 KB of RAM and typically 4 MB of flash. 3.3 V logic, PWM on almost any pin, 12-bit analog inputs, WiFi and Bluetooth, touch-sensing pins and a deep sleep mode for battery projects. The newer ESP32-C3 is a single RISC-V core at 160 MHz with WiFi and Bluetooth LE. Raspberry Pi Pico: an RP2040 with two Cortex-M0+ cores at 133 MHz (125 MHz by default), 264 KB of RAM and 2 MB of flash. 3.3 V logic, PWM on every pin, three 12-bit analog inputs, and eight PIO state machines that can generate or read almost any digital protocol in hardware. No wireless on the plain Pico; the Pico W adds WiFi and Bluetooth. ## Which one for which person Choose the Uno for a first course or a younger learner. Its 5 V pins drive LEDs and most hobby modules directly, it survives a lot of wiring mistakes, and nearly every beginner tutorial and kit is written for it. Its limits are memory and speed: a project with a color display or a lot of data runs out of 2 KB of RAM quickly. Choose the ESP32 when the project talks to a network: a sensor that posts readings, a device with a web page, anything you control from a phone. It is also cheap. The costs are 3.3 V logic, which means care with 5 V modules, a more complicated pin map with some pins you must not use, and an analog input that is noisier than the Uno’s. Choose the Pico for value and headroom, or if you want to learn MicroPython as well as C++. It is typically the cheapest of the three, its documentation from Raspberry Pi is excellent, and PIO lets it do tricks the others cannot, like driving LED strips or extra serial ports entirely in hardware. Like the ESP32, it is a 3.3 V board. ## The 5 V versus 3.3 V question This is the difference that damages real parts. The Uno’s pins work at 5 V. The ESP32 and the Pico work at 3.3 V and their pins are not 5 V tolerant, so feeding 5 V into one, from an Uno’s output or a 5 V sensor, can destroy that pin. The fix is a voltage divider or a level shifter. Going the other way usually works: 3.3 V is high enough for most 5 V inputs, though not all. It also changes resistor values. An LED on a 3.3 V pin with a 220 ohm resistor runs at roughly 6 mA instead of the 13 mA you get on an Uno, so it looks dimmer. A 150 ohm resistor brings it back up. ## What Mokxi models on each, honestly You can try all three boards here without buying any, and it is fair to say what that covers. The Uno is the most complete: the whole ATmega328P with its timers, UART, ADC, interrupts and sleep, though its I2C and SPI run in software here. The ESP32 DevKit runs one of its two cores, with GPIO, UART, a timer, ADC1 and LEDC PWM; its second core, Bluetooth, touch pins, deep sleep and ADC2 are not modeled, and WiFi is a simulated network with no real internet. The Pico runs one core with GPIO, PWM, UART and its timer; its second core, PIO, ADC, I2C and SPI hardware are not modeled. So for learning to wire and code a first project, all three work well here. For deep sleep current, PIO programs, touch sensing or real radio range, you need the physical board. There is also an STM32 Blue Pill on the site, a fourth option popular with people heading towards professional embedded work, and the Blue Pill register page shows what programming it close to the hardware looks like. ## Questions Is the ESP32 better than an Arduino? Faster, with more memory and with WiFi, yes. Easier for a complete beginner, usually not: the 3.3 V logic and the more complicated pin rules trip people up. Many people learn on an Uno and move to an ESP32 for their first connected project. Can I use the Arduino IDE with an ESP32 or a Pico? Yes. Both have Arduino cores you add through the Boards Manager, and most sketches written for an Uno compile for them with only pin numbers changed. Which board is best for MicroPython? The Pico, whose official documentation is written around MicroPython, with the ESP32 a close second. The classic Uno does not have the memory to run it. Mokxi runs C++ on all three, not MicroPython. Which is best for battery projects? Any of them can be, but the ESP32’s deep sleep, drawing microamps between wake-ups, makes it the usual choice for a battery sensor that reports over WiFi. A bare Uno board wastes power on its regulator and USB chip even when the processor sleeps. Related ## Keep going Blink an LED on the ESP32-C3, Step by Step Raspberry Pi Pico PWM: Slices, Channels and 1 kHz STM32 Blue Pill Blink with Registers, Not pinMode Arduino Simulators Compared: An Honest Roundup The Arduino simulator The ESP32 simulator The Raspberry Pi Pico simulator Every board Mokxi models ## Build this for real Open the editor, change a value and watch the number move with it. Nothing to install, and no account needed. Start building Open the editor