ArduinoStudio

Getting Started: Your First Arduino LED Project

Build a visual sequence that blinks the built-in LED on your Arduino Uno R3, 20 times.

Looking for one task, such as Wi-Fi, the phone app or sharing? How to Use ArduinoStudio has short steps for each one.

Prerequisites

Rather describe it than build it? Type “Blink the LED on pin 13 every second” into the AI Builder on an empty project, review the plan, and apply it. This guide builds the same project by hand, so you know what every block does.

Watch how (2 min): Start your first projectWatch how (2 min): Build logic with blocks and press PlayThe same project, narrated.

What We’re Building

A sequence that turns the built-in LED (pin 13) on for 1 second, then off for 1 second, repeated 20 times. The sequence looks like this:

Loop (20 repeats)
  └─ Standard LED → pin 13, ON
  └─ Wait → 1000ms
  └─ Standard LED → pin 13, OFF
  └─ Wait → 1000ms

Step-by-Step

1
Create a new project
Log in to app.arduinostudio.com and click the + button on your dashboard to create a new project.
2
Add a Loop
On the canvas, click the + button on your sequence. Switch to the Actions tab and click Loop. Click the Loop to open its settings and set Times to 20. Click Save.
3
Add LED ON inside the Loop
Click the + button on the Loop component. In the Components tab, open LED and click Standard. Click the new Standard LED block to open its settings:
SettingValueWhy
Digital pin13Pin 13 has a built-in LED — no wiring needed
Off/OnOnTurn the LED on
Brightness100%Leave it. Pin 13 isn’t a PWM (~) pin on an Uno, so the panel greys Brightness out and the LED runs at full brightness
ModestaticNothing to change: Mode shows “Coming soon” and stays at static. The Wait blocks do the timing
4
Add a Wait (1000ms)
Click + after the LED component. Switch to Actions tab and click Wait. Set Time to 1000 ms. This keeps the LED on for 1 second.
5
Add LED OFF
Click + after the Wait. Add another Standard LED. Set pin to 13 and Off/On to Off. Click Save. This turns the LED off.
6
Add another Wait (1000ms)
Click + after the LED OFF. Add a Wait with 1000 ms. This pauses 1 second before the loop repeats.
7
Connect your board
Plug your board into USB and click the plug icon in the toolbar. Choose Cable (COM port), then Add a board… — the browser shows a port picker; choose your board. A board you added before is listed as its own port row. If the picker closes with no board in it, the app lists what to try (a data cable, closing the Arduino IDE or Serial Monitor, the CH340 driver on Windows) with a Try again button. Connecting runs nothing yet. (On Firefox/Safari, run the Bridge, click the plug icon, choose More ways to connect… and use the Browser-agnostic — for Firefox/Safari/etc. row instead.)
8
Flash Firmata (first time only)
If the board does not have compatible Firmata firmware, follow the setup wizard to upload it from the browser on an Uno R3, a Nano (old or newer bootloader) or a Mega 2560. This replaces the existing sketch and lets ArduinoStudio drive the board live. Repeat this setup if you later upload a different sketch.
9
Press Play
Right after the board connects, a prompt under Play says Press Play: it runs on your board now. Click Run on my board, or close it with Not now and click Play when you are ready. Your Arduino’s built-in LED will blink — 1 second on, 1 second off, 20 times. You just controlled real hardware from your browser!

Your Sequence Should Look Like

#ComponentSettings
1LoopTimes: 20
2↳ Standard LEDPin: 13, On
3↳ Wait1000ms
4↳ Standard LEDPin: 13, Off
5↳ Wait1000ms

What Just Happened?

When you pressed Play, ArduinoStudio sent commands from your browser to the Arduino over USB using Web Serial and Firmata. The Loop ran 20 times: LED on, wait 1 second, LED off, wait 1 second. After the initial firmware setup, changing your visual sequence does not require uploading a new sketch. On Firefox and Safari, the Bridge relays the commands.

If the LED does not blink

  • Check that both LED blocks use pin 13, with the first set to On and the second to Off.
  • Make sure the sequence is ticked under Choose Sequences, or click the blue play bubble at the start of the sequence to run just that one. If only the Virtual Board changes, check that the physical board is connected in USB direct mode.
  • Try a USB data cable and close other programs using the same serial port, such as the Arduino IDE’s Serial Monitor. On Windows, a Nano or Uno clone with a CH340 chip needs the WCH driver installed once before it appears in the port list.
  • If the port is unavailable on a managed computer, ask your administrator to check serial-device permissions.

Next Steps

  • Try a Servo — Add a Servo component to move a motor arm
  • Add a sensor — Use a Photoresistor or Button to make interactive sequences
  • Use Check — Put a Check right after a sensor block. In the simulator and over USB direct, when the Check fails that pass stops there; through the Bridge, the input block waits until the Check is true. Either way, the blocks after it run only when the condition is true
  • See the wiring — Click 2 Wiring to see the circuit on a breadboard, build it wire by wire, and check your real board with EyeBuild. See the Wiring guide
  • Build a control panel — Click 3 App to add buttons and sliders that run your sequences. See the App Builder guide
  • Read the code — Click Arduino code in the toolbar to see this project as an Arduino sketch, and change the delay(1000); lines to watch the Wait blocks follow. See Dev mode
  • Share your project — Make it public and share the link. It starts running as soon as it opens
  • Watch the rest — The video tutorials go on from here: Loops and Checks, the App, Wiring, USB, ESP32 Wi-Fi, the phone app, the AI, the code and sharing. In the app, the ? buttons open the same videos

Build a smart room on an ESP32 in the live demo, in the preview with no board, account or install: open the demo