Circuits & Projects

This year’s Halloween project is a useless machine built with 555 timers. It’s a coffin with a switch. When you flip it off, a dark force rises from the coffin and flips it back on.

Controlling a Servo with 555 Timers

The idea for this project came after we published the simple 555 PWM circuit that controls a DC motor using a PWM signal created by a 555 Timer. I started thinking about the idea of controlling a servo instead.

After some experimentation, I realized that the frequency changed too much when I changed the duty cycle. So my servo would only move at random times.

If you are into baseball and would like a challenging ‘real-playing action’ baseball game, typically to exhibit your pitching skills, then you might like to construct this one. It is designed around four easily available and inexpensive digital ICs in the 4000 CMOS series along with some passive components.

In this guide, I’ll show you how to build a DIY sugar dispenser using parts made of cardboard.

By making the parts out of cardboard, it’s quick and easy to build and experiment with different ways to have your machine dispense sugar.

When you’ve built a cardboard-based sugar dispenser that you’re happy with, you can consider upgrading it by building the mechanics using other more durable materials (ex laser cutting plastic).

But for now, let’s build our cardboard prototype!

In this tutorial, you’ll learn how to use an ultrasonic sensor. Specifically, you’ll learn how to use the HC-SR04 module with an Arduino to measure the depth of a water tank.

An ultrasonic sensor is one of those things that some people don’t like getting into just because it sounds complex to use and understand. But the fact is, it’s one of the most accessible and fun accessories for those who like to dabble in microcontrollers.

Do you want to build something on your own for Christmas, but don’t have much time? Or no experience? Then this project is for you.

One of the easiest ways to make a Christmas circuit that looks cool when you don’t have much time is to use a color-changing LED.

A color-changing LED looks like a normal LED, but it has an integrated chip that controls the LED and automatically cycles through different colors.

In this Halloween electronics project, I’ll show you how to make a cool Jack-O-Lantern. I used a 3D-printed carved pumpkin, but a real one works just as well (or even better!).

The project is based around three normal LEDs that I control so that they look like a flickering flame. Since my “pumpkin” was very small, I used 3mm LEDs. For bigger pumpkins, I recommend using bigger and brighter LEDs. For example these ultra-bright orange LEDs.

The LEDs are connected in series with a resistor to the PWM pins on the Arduino so that I can control the brightness. And in the code, I change the brightness of each LED to a random value for every 50 milliseconds.

The result? Check out the video below:

Circuit ideas are everywhere! There are many places to find cool circuits.

The greatest sources for my inspiration are hacker/maker/electronics blogs, schematic webpages, hobby project pages, and open-source hardware companies.

Or you can also check out some electronic kits for inspiration.

Sometimes I just want to try to replicate an electronic circuit I’ve found on the web. Either because it is something I need or just to prove to myself that I can do it. Like this amplifier circuit diagram.

Sometimes I find something cool that I want to modify and improve on. And other times I get completely new circuit ideas out of the blue that I want to build.

In this tutorial, you’ll learn how to build an automatic night light circuit that turns on when it gets dark. It’s a simple circuit that you can build on a breadboard.

This circuit shows you how to do it with an LED. But you can use the same principle to turn on bigger and brighter lights too.

Find the breadboard diagram and parts list below the video.

In this short tutorial, you will learn how to build an Arduino Theremin. You only need three components plus the Arduino, wires, and breadboard.

Use the breadboard diagram or the video below to see how to connect everything.

I put together this Voltage Unit (VU) meter using LEDs on a breadboard the other day. It only has 4 LEDs, but can easily be expanded to more:

It’s basically a simple display for showing a value. It’s originally for showing signal level in audio circuits, but there’s no reason you can’t use it to show temperature, rain intensity, light level, or whatever other value you are measuring.

Do you want to build a circuit that blinks a light? This inverter-based circuit is simple, and it’s small enough to fit on a breadboard.

The circuit uses standard basic electronic components and you can build it even if you have never built anything before. Check out the full build instructions in the video below:

Scroll down to find the complete circuit diagram, component list, and step-by-step instructions (in text-form) on how to build this circuit.

Do you want a fun and easy-to-build circuit? Here’s the simple, but fun Atari Punk Console – with schematics and parts list. It’s a quick build, so you can easily build it during an evening.

It takes its name from the old Atari computers of the 80s because it makes similar sounds.

And after my (not-so-intense) research (I basically just read about it on Wikipedia), I’ve come to learn that the circuit was first published in a Radioshack magazine in 1980.

Here’s a short clip of me playing with the circuit I built:

“The music that we are hearing is actually 8 seconds old”

That was my friend’s claim.

My friends and I were about 13 years old, and we heard loud music coming from a big event about 3 kilometers away.

“The speed of sound is 340 meters per second, and the event is 3 kilometers away. So that means what we are hearing now is actually what they played 8 seconds ago at the stadium” our friend told us.

I found it hard to accept because I didn’t know too much about sound and how it worked.

But our friend was really good at memorizing facts.

And he was right.