Arduino projects for beginners, in the order they build on each other
- 192parts on the bench
- 25boards running now
- 1.00xreal time, on every board
Most lists of beginner Arduino projects are a pile of photos. This one is a path: twelve projects in an order where each one adds a single new idea to the last, from one blinking LED to a keypad door lock. Every project on it runs in your browser, on the real sketch, with a tutorial that has the wiring table and the code explained.
The traffic light above is number three. It is running now on a simulated Arduino Uno; press the button on the breadboard to ask to cross. You do not need a kit to start, and when you do buy one, the parts lists below are the parts in a typical starter kit.
Week one: outputs and inputs
1. Blink an LED. One LED, one 220 ohm resistor, pin 13. You learn pinMode, digitalWrite and delay, and why the resistor is there. Start with the blink tutorial.
2. A button that works. A pushbutton on an input with the internal pull-up, and the debounce that stops one press counting as five. You learn digitalRead, INPUT_PULLUP and why pressed reads LOW. The button debounce tutorial covers it.
3. A traffic light with a crossing button. Four LEDs, a button and a sequence, with the button on an interrupt so a press is never missed. You learn to structure a program in phases, which is most of what real firmware is. The traffic light tutorial walks through it.
4. Blink without delay. Two LEDs at two different rates, which delay() cannot do. You learn millis() timing, the idea every project after this one uses.
Week two: analog in, analog out
5. A dimmer. A potentiometer on A0 sets the brightness of an LED on pin 9. You learn analogRead, which turns a voltage into 0 to 1023, and analogWrite, which is PWM. The potentiometer tutorial has it running.
6. A night light. A light-dependent resistor in a voltage divider fades a lamp up as the room goes dark. You learn that most analog sensors are a resistor that changes, read through a divider.
7. A servo fader. A slide potentiometer sets the angle of a hobby servo. You learn to use a library and to map() one range onto another. The servo tutorial explains the pulse.
8. A thermometer. A TMP36 on A0 and the temperature on a 16x2 LCD, in Celsius, with the one line that adds Fahrenheit. You learn to turn a voltage into a real unit, and the one offset everyone forgets.
Week three: sensors, sound and displays
9. A parking sensor. An HC-SR04 ultrasonic ranger and a buzzer that beeps faster as the wall gets closer. You learn to time an echo in microseconds and turn it into distance.
10. A metronome. A piezo clicks a beat and two buttons change the tempo. You learn how a note is a square wave, and to read buttons while you wait.
11. An electronic die. A button rolls a number onto a seven-segment display. You learn that a display is just seven LEDs, and a segment font that says which ones make each digit.
12. A keypad lock. A 4x4 keypad, a relay and an RGB LED: type 1234 then # and the door lamp clicks on. You learn to scan a keypad matrix and keep track of what has been typed so far, which is where beginner projects end and real ones start.
How to use this list
Open each project, press Run, and play with it before you read anything. Then read the tutorial, and change one thing: a delay, a pin, a threshold. Breaking it on purpose and fixing it teaches more than any amount of reading. Every tutorial ends with a Common mistakes section, and those are the mistakes you will make on real hardware too.
If you are working toward a science fair, projects 6, 8 and 9 each make a good start, because they measure something. The science fair page has project ideas that go further.
After project 12, the natural next steps are a joystick or an OLED display for a small game, an L293D to drive a motor both ways, or an ESP32 to put a project on WiFi. Each of those has a tutorial of its own, built the same way, with the circuit running at the top.
Everything here runs in a Chrome tab, including on a school Chromebook, so a class can work through it without a kit per student. When you move to real hardware, every sketch is standard Arduino code, and each tutorial says where the simulator differs from the board on your desk.
What you need to buy, if anything
Nothing, to start. To build all twelve on a desk, a typical Uno starter kit covers most of it: an Uno, a breadboard, jumper wires, LEDs, 220 ohm and 10 k resistors, pushbuttons, a potentiometer, an LDR, a piezo and a servo. The TMP36, the HC-SR04, the LCD, the seven-segment display and the keypad are in many kits and cost little on their own from US electronics suppliers such as Adafruit, SparkFun or Digi-Key.
Questions
What is the easiest Arduino project for a beginner?
Blinking an LED: one LED, one resistor and three lines of code. It teaches the loop every other project uses. After that, a button, then a traffic light.
Can I do Arduino projects without buying a kit?
Yes. Every project on this page runs in a browser simulator on the real sketch, free and with no account needed. Buy the parts when you want to build the one you like best.
How long does it take to learn Arduino?
Working through these twelve projects, a few each week, covers the core of it: digital and analog input and output, timing, libraries and simple displays. Real projects build on exactly those.
Keep going
Build this for real
Open the editor, change a value and watch the number move with it. Nothing to install, and no account needed.