Arduino Basics Lesson 1-1: “Hello, World!”

For the “Arduino For Kooks” course, I recommend you get the Arduino Starter Kit available here.

“Hello, World!” is the most basic “program” developers use to test their understanding of a piece of hardware or programming language. On the Arduino, the “blink” sketch stands as the most basic bit of code that will run with human-readable output.

Let’s get our feet wet with the Arduino platform by assembling a slightly more complex version of “blink” using an external LED.

The Circuit:

Connect a jumper wire from pin 2 to the anode of the LED. The anode is the “+” side of the LED and has a longer leg. The easy way to remember this is that the extra little bit of lead can be clipped off to make a plus sign on the leg.

Connect a 220R resistor to the cathode of the LED. We’re using a 220R resistor because it will allow the most voltage to come through while reducing the overall current. I’ll explain how this works in a future video.

Connect the resistor back to the ground pin of the Arduino with another jumper.

The Sketch:

"Hello World" Blink Sketch

Turns an LED on for one second, then off for one second, repeatedly.

modified 8 May 2014
by Scott Fitzgerald
modified 2 Sep 2016
by Arturo Guadalupi
modified 8 Sep 2016
by Colby Newman
modified 3 Aug 2019
by Matthew Eargle

This example code is in the public domain.

int ledPin = 2; //Define ledPin as integer variable with value of 2

// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin ledpin as an output.
pinMode(ledPin, OUTPUT);

// the loop function runs over and over again forever
void loop() {
digitalWrite(ledPin, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(ledPin, LOW); // turn the LED off by making the voltage LOW
delay(1000); // wait for a second

Can you determine what the Arduino is doing at each line in the code?

What happens if we change the values of some variables?

What happens if we change the time parameter of the delay?

Coleco Electronic Quarterback Teardown

In the late 1970s-early 1980s, we didn’t have fancy touchscreens or dot matrices with stereo sound, we had an LED matrix and a handful of 7-series logic chips AND THAT WAS GOOD ENOUGH FOR US! In this video, we’ll teardown the iconic Coleco Electronic Quarterback handheld game and see just exactly what makes it tick. Later, as part of Project Hawthorne on element14 Presents, we’ll build a new LED handheld game from scratch and attempt to repair this one, so stay tuned!

Watch the rest of Project Hawthorne on element14

How To Build An Arduino-Controlled LED Matrix

If you need more blinkenlights than Pin 13 can provide on its own, it’s time to build an LED matrix to make the most of the few pins that you have! In this video, we’ll take a look at a simple transistor-based LED matrix and how it can be driven by an Arduino Nano. It’s all part of Project Hawthorne for element14 Presents!

Check out more of Project Hawthorne at element14 Presents

Sharp Atomic Alarm Clock Backlight Hack

This Sharp atomic alarm clock features a nice backlight that shuts off after 5 seconds. My mother-in-law, however, would prefer the light stay on so she can see it in the middle of the night. In this video, we’ll open up the Sharp atomic alarm clock, override the backlight switch, and install a DC converter so that she doesn’t have to worry about batteries running out in the middle of the night!

It’s a Sorrowful Day in the Neighborhood (AJC)

Remember when the days were long
And rolled beneath a deep blue sky
Didn’t have a care in the world
With mommy and daddy standing by…
This is the end of the innocence.
–Don Henley
In the 16 years following the passing of Fred Rogers, we have seen our country fall into the pits of fear and loathing, the world has gotten louder and louder, and mass communication seems–at best–a weapon. Every year I mourn the passing of a quiet hero. A hero who spoke softly and slowly, but could best even the most ardent critics with his grace and his authentic love for humanity. A hero to at least three generations of children. A hero who maintained his humility and taught a nation how to care.
There may never be another Mr. Rogers, but we could sure use one right about now. Until then, I’ll keep his memory alive and do my best to live according to his example.

The following clippings are from the February 28 edition of the Atlanta Journal-Constitution, posted here for archival purposes. If anyone at The Paper wants me to take it down, that’s fair–but y’all gotta put it back up on your site.

Download the clipping in PDF format

Digital Archaeology: Exploring An Old Hard Drive

As part of Project Xyberpunk for element14 Presents, I wanted to explore the original, stock hard drive from the Xybernaut MAIV wearable computer. In this video, I’ll use Linux Mint to explore the contents of the drive, see what kind of software support was required for the Xybernaut MAIV wearable computer, and get an idea of what it would take to replicate the system on modern hardware.

Adventitious Geekery and other distractions created or curated by Matthew "Atari" Eargle