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Intro to Arduino

Code Challenge

Blink Those Big Brown Eyes!



10 minutes
Computer Science

This activity introduces a simple look at existing computer code and challenges you to change it. No code experience? Have no fear! It’s simple!


Coding is the act of writing instructions in a language a computer understands so that it can execute work. Computers don’t speak our language so we need to learn how to talk to them in languages they do understand. Just like learning a foreign language to converse with other people around the world, programming languages enable you to talk to computers! Examples of languages are Aduino, Python, and C++. In this activity you’ll be challenged to change up some Arduino code and make it your own!


Understand & Recognize:

  • “Arduino” as a hardware and software platform for making projects.
  • “Open Source” as a model of creating and sharing information.
  • “input” and “output” in both hardware and software based on looking at Arduino projects.
  • “Community” in the sense of people connected through a common interest such as making cool projects with Arduino.
  • “Computer programming” or “coding” means writing instructions for the hardware to follow.

What You'll Need

This activity can be done with no materials – look at the code and figure out how it works! If you have the Arduino IDE installed and an Arduino board handy, all the better! You can test your changes and do some real coding.

Important Terms

Hardware: The”physical” part of a computer or device. If you can thump it on a table, it’s probably hardware.

Software: The computer program or “instructions you write” for the hardware. It’s not something you can thump on the table, but the hardware is worthless without it.

Sketch: A “sketch” in Arduino lingo refers to a computer program you’ve written in the IDE to run your Arduino hardware.

Code: The actual lines of instruction in your computer program (sketch) are code. Code is written in different languages such as Arduino. Code is also a verb – “I’m going to code for a few hours – see you later!”

Arduino IDE: IDE stands for Integrated Development Environment which is a mouthful, but it just means you have all the tools you need to write fun instructions for your Arduino microcontroller to follow.

Input: Things that go “into” a computing system are input. When you type on your phone you are “inputting” information.

Output: Something that come out of. your computing system, like the display on a smartphone, is “output.”


Read Overview and watch video

Coding Challenge - Modify the Code!

Remember that “Blink” program? Take another look now and and challenge yourself to change the Arduino code by modifying
Blink as follows:

  1. Have the LED alternate being on for 2 seconds and off for 2 seconds.
  2. Have the LED alternate being on for 1 second and off for a half a second.
  3. Have the LED alternate being on one for a half second and off for a full second.

Look at the rest of the code.

  • Do you see other things you understand and could modify?
  • Who wrote this program?
  • If you write changes to this program and share those back with the world would you like to see your name on the new code?
  • What is the output of this program?

Cool bananas – coding holds no fear for you!

It’s now time for some community and group hugs. Next and final stop – a collaboration activity. Enjoy!

Next Step, Collaboration!

Educator Info

This coding challenge is an extension of PDQ2, “A Peek Under the IDE Hood.” Review the educator notes associated with PDQ 2 and the more extensive information provided in the Overview section if necessary.

Educator Info

Intro to Arduino by Robert O. Grover & Team databot is licensed under a Creative Commons Attribution 4.0 International License. Permissions beyond the scope of this license may be available at