The latest AddOhms looks at why you need a pull-up resistor when using push-buttons. This video goes into what happens when you leave a pin floating, what a floating pin means, and how the pull-up works. You can get more information about the video on the AddOhms Episode page.
This tutorial is the 2nd time I’ve made a video on pull-ups. Despite being a single resistor, it can be a difficult topic for new hardware designers to understand. The pull-up video was the first video tutorial I ever made. In fact, the YouTube version uses YouTube’s “stabilization” algorithm, which gives the video a very warped feel.
AddOhms #15 shows improvements in skill over the past couple of years!
Question: What’s another topic that I need to cover in an AddOhms Tutorial? You can leave a comment by clicking here.
The other day my friend called me up. He told me how much he missed building circuits and wanted to start again with the Arduino.
So he asked me “which Arduino starter kit is the best to buy?” At which point, I drew a long breath. Easy question, not always an easy answer.
Picking out an electronics kit depends on a number of factors. You should consider:
What you already have
What you want to do
#1 and #2 are probably pretty easy to figure out. For many beginners, it’s “not much” and “nothing.” When you don’t know #3, what you want to do, then it gets trickier. Coming back to my friend, what did I do? Well, I went out and bought each one of the kits in this post. I put myself in his shoes and maybe these are your shoes as well.
The funny thing about schematics is that they are much easier to draw than they are to read. There are many common circuits. When an experienced engineer looks at them, it’s like a second language. When someone less experienced looks at them, it looks like random lines and symbols thrown together at the last-minute. (Or maybe that’s just the schematics *I* draw.)
Other than reading Schematic Symbols themselves, one of the basic skill necessary to read a schematic is recognizing series and parallel circuits.
Learning to a breadboard is critical when adding electronics to a project. A skill often overlooked is how to use breadboard jumper wires correctly. For example, when I breadboard a circuit I only use Red, Green, or Blue for positive voltages and Black for ground. Other colors, it depends on the functions of the wire. The idea is to keep it clear when I look at the board, what each wire is doing.
This video from Make is a great overview of how to develop a skill, or habit, around using breadboard jumper wires in your circuit.
Engineers make a schematic to explain their circuits.
One time I was looking for a non-tourist pub in Japan. I asked someone for help. She said, “I’m sorry, but I do not speak good English. I will bring my friend, and she will draw you a map.” (Exact quote!) The map her friend drew, gave directions to a bar with a “Neon Yellow Sing.” She meant “sign.”
The map was the method we used to communicate with each other, even though we didn’t both speak English. With this crude but useful map, I could find my next drinking place destination.
Schematics are the same as this map. Even if you don’t speak the same language, you can communicate how a circuit works when you make a schematic.
To save time, breadboard pins or just lack of knowledge people try to skip adding eve one decoupling capacitor to a circuit. Either on IRC or in Forums you can almost always see it coming: “randomly, my circuit stops working” And then, “what do you mean a decoupling capacitor?” question.
While working on breadboard Arduino, I came across some unexpected measurements. Initially, the only capacitors on the breadboard were the two 22pF from crystal to ground and the capacitor connected to RESET for Auto-RESET.
When I was in elementary school, I remember Ms. Coker telling us we needed to memorize our multiplication tables because we wouldn’t always have a calculator. Years later in college I was told, “learn to use the library, it’s not like you can carry the internet in your pocket.”
Seems strange that I always carry 3 devices on me that do both.
Today a generation of people are growing up with the mass of all human knowledge available to them from birth. No formal education is necessary. And the only need is a modern device with WiFi.
However. Not all accessible information is equal. Which is why I created the AddOhms Electronics Tutorial Video series. Instead of teaching Electrical Engineering as an engineer to other engineers, I’ve created a series that uses simple language to explain electronics to anyone. And now the growing YouTube series, is available for sale on DVD!
Sometimes the hardest lessons are the ones you have to learn multiple times. When getting started with Electronics circuits, there’s a handful of things that can ruin a day (or experiment.) Here are 6 mistakes I made when I got started, and mistakes I see in the beginner classes I teach.
When your project needs a transistor there are tons of choices. Which makes answering the question “Which transistor should I use or buy?” a daunting task. Fear not, before wading through spec sheet after spec sheet consider of these 4 general purpose transistors. Every electronics enginerd’s toolbox should have a few of each.
Smoke detectors beep when their backup battery dies, which always seems to occur in the middle of the night (at least for me.) These backup batteries are usually a small rectangular 9V. They have become popular choices for electronics projects. If you need your Arduino project to last longer than a day, this isn’t the battery you want to use. Here’s why.