A Really Simple Arduino Oscilloscope Tutorial

Arduino Oscilloscope

This Arduino oscilloscope is perfect if you need an oscilloscope right now, but all you have is an Arduino.

Update: There’s an even easier way to do this now. Check out my new article on how to build an Arduino oscilloscope with 7 lines of code.

I needed an oscilloscope to debug my Radar Arduino library.

The code worked perfectly when it was not in “Arduino library”-form. But when I modified it into a library, it just didn’t work at all.

Since the radar module (from https://www.xethru.com) was using the UART, I didn’t have any way of checking what was going on.

So I needed an oscilloscope to check if there was actually any action on the UART lines.

Intel Galileo Projects: Simple DIY Weather Station

DHT11 temperature and humidity sensor

galileo-dht11I’ve played with the Intel Galileo a lot lately, so now it’s time to build some Intel Galileo projects!

In this project I built a very simple weather station that records the temperature and humidity and saves these to a memory card.

I’ll show you how to read temperature and humidity from a DHT11 sensor with the Intel Galileo. Then how to save these values to an SD-card.

Getting Started with Intel Galileo

Getting started with Intel Galileo Board

Getting started with Intel Galileo is almost like getting started with Arduino. But with a few twists.

I recently got my hands on an Intel Galileo. But it took me quite some time to get it up and running.

So I decided to write a small guide to show you exactly how I got started with my Intel Galileo.

How to find LED voltage and current

Blinking an LED using a relay

I got this question from Awaji about the light-emitting diode (LED):

Simple circuit to find LED voltage

[Awaji]: How can I know the LED voltage and the current ratings of an LED? Also, how is the resistor of an LED chosen? Thanks

[Oyvind]:

Here are three different ways to find the LED voltage and current:

  1. The easiest way is to look it up in the datasheet, or the store where you bought it. Look for LED forward voltage and the Test Current.
  2. You could find the LED voltage by using a multimeter with a diode function.
  3. You could connect a battery to the LED and a potentiometer. Start with high resistance on the potentiometer and gradually decrease it until you have a nice brightness. Then measure the voltage over the LED, and measure the current going through the circuit.

Arduino Radar Tutorial: Fading an LED With My Breath

Arduino radar project on a breadboard

I built this Arduino radar project, where I control the brightness of an LED with my breath. In this tutorial, I will show you exactly how to do it.

It was an experiment to get the XeThru radar to work with Arduino. I plan to expand on this later and build more useful applications.

And I will share with you how to connect the hardware, and how to create the Arduino code.

Just to be clear: This is not a sonar pretending to be a radar. This is a radar. With electromagnetic waves.

SexyCyborg is not Your Ordinary Electronics Geek

SexyCyborg with her DIY underlit LED skirt

SexyCyborg is an electronics geek out of the ordinary. And I love to see people being different than the norm, especially in the hobby electronics world.

So, I knew I had to interview her.

How to fix your blinking relay circuit

Blinking an LED using a relayI really like the circuit that blinks a light with a relay.

Like this:

If you connect a battery to the electromagnet of a relay, through its normally closed contact, you will get a relay that switches on and off really fast.

If you add a big capacitor (like 1000 µF) over the electromagnet, the electromagnet will stay on longer.

How to Create Your Own Resistor

resistors-intertwined

Check out this simple tip that Michael sent me:

[MICHAEL]:
“I was making a small practice audio amplifier and was in need of a 2.5 Ohm resistor. I didn’t
have one and didn’t want to wait for an order to be fulfilled.

Mythbuster: Can you fix broken computer parts in the oven?

usb-mouse-kretskort-underI’ve done some research.

A couple of weeks ago Tek.no, a Norwegian tech-magazine, asked me if I could write an article for them.

There are a lot of people online claiming they have fixed broken graphic cards and other hardware, by baking it in an oven.

How to send a balloon into space?

balloon-project-julio-1

This is a guest post from Julio Cesar Torres. He sent a balloon to space after learning about electronics! Read his captivating story below:

When I was a kid, I was always eager for Sunday morning, just waiting for the time to watch Carl Sagan’s “Cosmos” on TV.

Back then, my couch turned into a spacecraft and I could go to places light-years distant from home. All was discovery and astonishment.

5 top mistakes beginners make when soldering

Adding Solder To Pad

Are you doing this?

Don’t worry, I’ve done all of these mistakes myself.

And sometimes it works.

But by learning the correct soldering technique, you reduce the chances of mistakes in your circuit caused by a bad solder joint.

1. Removing iron before applying solder

When I teach someone how to solder, I usually say that you should first heat the pin and the pad, then apply the solder.

But sometimes my explanation isn’t clear enough. I’ve seen students heating the pad and the pin, then removing the soldering iron before trying to apply the solder.

What is the RIGHT Soldering Temperature?

Cleaning Soldering Iron With SpongeThe right soldering temperature is something many don’t really think about.

But, have you ever used one of those soldering irons with a variable temperature setting?

If you have, you might be wondering the same thing as Jyri. Jyri wrote to me in an email about soldering and asked: “I always wondered – what is the right soldering temperature in various situations?”

This Mono Amplifier Circuit is Super Easy To Build

PCB Layout of the mono amplifier circuit

PCB Layout of the mono amplifier circuitThis is the easiest mono amplifier circuit to build, as far as I know.

I love it because it is powerful enough to play pretty loud. And it doesn’t need a pre-amp, heat-sink or any weird transistors.

All it requires, is a few standard capacitors, a couple of resistors and a potentiometer.

It will give you 4.7 Watts of power. This should be enough to play music in the park with some friends and a couple of brewskies.

I’ve added the schematics, PCB design and Gerber files a little further down the page.

10 things you can build with electronics

protostack-board“What can you build with electronics?”, she asked me…

“Anything!” I said.

She looked at me with a blank stare. Apparently that was not a satisfying reply.

This happened to me a few days ago.

Sometimes I get too deep into electronics that I forget “normal” people don’t necessarily understand what you can do with electronics.

So…

Circuit Board Recycling

Circuit board recycling necessary

Circuit board recycling necessaryCan you get money for your old circuit boards?

Apparently yes…

Anne Staley wrote to me a while back.

She was very enthusiastic about the environment and recycling. And she asked me if she could write an article on my blog about this.

I answered that it probably wasn’t something for my blog.

But she persisted. And she wrote the article and sent me. And as I read through it, I realized that it could be an interesting thing to learn about. Even as a hobbyist.

It turns out that you can actually earn money on your old circuit boards. Circuit board recycling sounds like a good idea =)

Read the article below: