Run the Built-in Blink Example
Open, compile, and upload your first working sketch.
Run the Built-in Blink Example is a free Arduino & IoT Academy lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Arduino & IoT Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
The Hello World of Hardware
Every maker starts with Blink, the classic first sketch. It makes the onboard LED flash, proving your whole setup works. 💡
Open the Examples
The IDE ships with ready-made sketches under File then Examples. You do not even have to type anything yet.
Find Blink
Go to Examples, then Basics, then Blink. The IDE opens the complete code in a fresh window for you.
Look at setup
The setup block runs once at startup. Here it tells the built-in LED pin to act as an output.
void setup() {
pinMode(LED_BUILTIN, OUTPUT);
}Look at loop
The loop block repeats forever. It turns the LED on, waits, turns it off, waits, then starts over.
void loop() {
digitalWrite(LED_BUILTIN, HIGH);
delay(1000);
digitalWrite(LED_BUILTIN, LOW);
delay(1000);
}What HIGH Means
Writing HIGH sends voltage to the pin, lighting the LED. Writing LOW removes it, turning the LED off.
What delay Does
The delay call pauses the program for the given milliseconds. Here 1000 means a full one-second wait.
Compile It
Click Verify to compile Blink. A clean run with no red errors means the code is ready to upload.
Upload It
Press Upload to flash Blink onto the board. Watch the tiny lights flicker as the code transfers over USB.
Watch It Blink
The orange onboard LED now flashes on and off once per second. You just made hardware do your bidding. 🎉
Make It Yours
Change both delay numbers to 200 and upload again. The LED blinks faster, proving the code is truly under your control.
Quick Check
Let's check how to speed the blink up.
Recap
You opened Blink, read setup and loop, uploaded it, and tuned the delay. Your first smart device is alive. 🎉
Frequently asked questions
Is the “Run the Built-in Blink Example” lesson free?
Yes — the full text of “Run the Built-in Blink Example” is free to read here on the web, and the Arduino & IoT Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Arduino & IoT Academy course, upgrade to CoddyKit PRO.
What will I learn in “Run the Built-in Blink Example”?
Open, compile, and upload your first working sketch. You practise Arduino & IoT Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Arduino & IoT Academy?
No prior experience is required. Arduino & IoT Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Run the Built-in Blink Example” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Arduino & IoT Academy lesson?
Yes. Every Arduino & IoT Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Tour of the Arduino Uno
- Installing the Arduino IDE
- Pick Board & Port, Then Upload
- Run the Built-in Blink Example