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Arduino vs Raspberry Pi: which should you start with?
They look alike on a shop page, but they are different kinds of machine. Here is what that means once you try to make something move.
The short answer. An Arduino is a microcontroller: it runs one program, starts the instant it gets power, and is very good at reading sensors and driving motors. A Raspberry Pi is a small Linux computer: it runs an operating system, Python and camera software, and is good at "thinking" jobs like computer vision.
For a first robotics project, start with an Arduino. Add a Raspberry Pi (or a laptop) later, when your robot needs a camera, Wi-Fi or heavier code.
The one difference that matters
Think of a robot as a body and a brain. The Arduino is the nervous system: it reacts in microseconds, reads a light sensor or a knob directly, and keeps a servo steady, with nothing else running that could get in the way. It has no operating system, no desktop and no files. You write a sketch on your computer, upload it over USB, and the board runs that sketch every time it powers on.
The Raspberry Pi is the brain. It boots Raspberry Pi OS (a version of Linux), connects to a monitor, keyboard and Wi-Fi, and runs many programs at once. That makes it great for recognizing objects in a camera feed or hosting a web page to control your robot, but the operating system can pause your program at any moment, so precise timing is harder.
Side by side
Four common boards. The Arduino Uno R3 is the classic beginner board; the Uno R4 Minima is its current, faster version. The Raspberry Pi Pico 2 is the Raspberry Pi company's own microcontroller, which is closer to an Arduino than to a Pi 5.
| Arduino Uno R3 | Arduino Uno R4 Minima | Raspberry Pi Pico 2 | Raspberry Pi 5 | |
|---|---|---|---|---|
| What it is | Microcontroller | Microcontroller | Microcontroller | Single-board computer |
| Chip | ATmega328P, 8-bit, 16 MHz | Renesas RA4M1, 32-bit Arm Cortex-M4, 48 MHz | RP2350, 32-bit dual-core, 150 MHz | Broadcom BCM2712, quad-core 64-bit Arm Cortex-A76, 2.4 GHz |
| Memory | 2 KB SRAM, 32 KB flash | 32 KB SRAM, 256 KB flash | 520 KB SRAM, 4 MB flash | 1 to 16 GB RAM, plus a microSD card or SSD for storage |
| Operating system | None | None | None | Raspberry Pi OS (Linux) |
| Usual language | Arduino C++ | Arduino C++ | MicroPython or C/C++ | Python, plus almost any language |
| Analog inputs | 6 | 6 | 3 | None built in (needs an add-on ADC chip) |
| Pin voltage | 5 V | 5 V | 3.3 V | 3.3 V (not 5 V tolerant) |
| Power | USB or 7 to 12 V barrel jack | USB-C or 6 to 24 V input | Micro-USB or 1.8 to 5.5 V | USB-C, 5 V at up to 5 A (official 27 W supply) |
| After power on | Runs your code at once | Runs your code at once | Runs your code at once | Boots the OS first; shut it down properly |
Specs from the makers' product pages and datasheets (see sources). Prices change often, so we left them out; microcontroller boards cost much less than a Pi 5 once you add its power supply and storage.
Pick Arduino when your robot needs to…
- Read sensors and drive motors directly. Ultrasonic distance sensors, line followers, servos and motor drivers all have well-tested Arduino libraries and wiring guides.
- Run on batteries. A microcontroller draws far less power than a Linux computer, and you can switch it off at any time without harming anything.
- React with exact timing. Balancing, counting wheel turns or generating steady pulses is easier when nothing else is running.
- Teach the basics. With one LED, one button and ten lines of code, a beginner sees exactly how code turns into something physical. That is why most robotics classes, including ours, start here.
Pick Raspberry Pi when your robot needs to…
- See. Camera-based tasks such as following a colored ball or recognizing objects with OpenCV need a real processor and memory.
- Talk to the internet. Wi-Fi, a web dashboard or streaming video are all built in on a Pi.
- Run bigger software. Python libraries for AI, data logging to files, or ROS 2 (the framework many research robots use).
- Be a computer too. Plug in a screen and keyboard and it is a full desktop for learning Linux and Python.
Or use both
Many real robots split the work: a Raspberry Pi (or a laptop) handles the camera and decisions, and an Arduino handles the motors and sensors. The two talk over a USB cable as a serial connection, with the Pi sending simple commands like "turn left 20 degrees" and the Arduino doing the precise part.
A laptop can play the brain role too. In our Vision Robotics camp, for example, students track a ping pong ball with a USB webcam and OpenCV running on their laptop, and the laptop tells a pair of servos where to point.
Four mistakes beginners make
- Wiring a 5 V sensor straight into a Raspberry Pi pin. Pi pins are 3.3 V and can be damaged by 5 V. Use a level shifter or a voltage divider, or pick a 3.3 V sensor.
- Powering motors from the board. Motors pull much more current than a board pin can give, which causes resets or worse. Use a motor driver and a separate battery, with the grounds connected.
- Pulling the plug on a Pi. Cutting power while Raspberry Pi OS is writing can corrupt the SD card. Shut it down first.
- Expecting a Pi to read a knob. A potentiometer or many simple sensors give an analog voltage, and the Pi has no analog inputs. An Arduino reads it with one line of code.
Our recommendation
For a middle schooler or anyone new to electronics: buy an Arduino Uno (R3 or R4) starter kit with a breadboard, jumper wires, LEDs, a servo and an ultrasonic sensor. Work through the official examples, then build something that moves. Once you can make a robot drive and avoid a wall, you'll know exactly why you might want a Raspberry Pi for the next one.
Sources
- Arduino Uno R3 and R4 Minima specs: docs.arduino.cc/hardware/uno-rev3 and docs.arduino.cc/hardware/uno-r4-minima
- Raspberry Pi 5 specs and power supply: raspberrypi.com/products/raspberry-pi-5
- Raspberry Pi Pico 2 specs: raspberrypi.com/products/raspberry-pi-pico-2
- Raspberry Pi GPIO voltage: Raspberry Pi hardware documentation
Spotted a mistake? Email hello@sparkobotics.com and we will fix it.