Beginner Concepts: Electronic Jack-in-the-box

April 5, 2010 by 7 Comments

Behold the electronic Jack-in-the-box. Open the lid or enter the wrong combination and you’ll set off an alarm.  But if you get the right 6 combination code entered using the three buttons you’ll be rewarded with a little ditty and the appearance of the Jack (who lives in the box). [Jeremy Blum] designed this as part of his introduction to rapid prototyping class at Cornell University. See his description of the project after the break.

When he shared the link with us he mentioned that this might be a fun project for beginners and we couldn’t agree more. The design is easy to wrap your mind around using the provided schematic. The source code package includes PDF files that contain well commented code segments along with their descriptions. You can use this to get comfortable with driving a speaker and servo motor using an Arduino, as well as to read from two different types of inputs. We are especially interested in the hardware debounce implemented for the switch that detects if the lid is closed. Software debouncing is pretty much the standard these days but because an external interrupt is used to read the switch that method won’t work here.

If you’ve got an Arduino and few of these components why not give this a try?

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Beginner Concepts: LPT Instead Of UC

March 27, 2010 by 28 Comments

We see it all the time, a post based on an Arduino board with multiple comments calling it overkill. How exactly should you control your homemade peripherals if you’re not using a microcontroller (uC)? [JKAbrams] and [Tim Gremalm] answered that question with this printer port (LPT) adapter. They wanted an indicator light when someone in an IRC room was talking to them. By connecting a blue rotating light through a relay to the output of this fob they’ve done just that, but there’s room for much more.

The adapter uses a Darlington transistor array IC to protect the computer. A resistor between the LPT and the base pin on the chip ensures that current flow will be well within the safe levels for the computer. The Darlington transistor amplifies the output using an external power supply in order to drive heavier loads.

If you want a deeper understanding of the printer port check out this tutorial. LPT ports are becoming less common and that’s why so many projects are migrating over to USB (plus there’s no need for external power with most USB connected projects) but if you’ve got one, it’s probably not being used for anything else.

Beginner Concepts: 555 Push Button Toggle

February 2, 2010 by 29 Comments

PIC, AVR, and Arduino are ubiquitous in projects these days and a lot of the time it’s easy to over-complicate things with their use. In this case, [Tod] wanted to use a momentary tactile switch to turn something on and off. Instead of going with a microcontroller he built the circuit around a 555 timer. What he really needed in this case is a flip-flop but lacking a chip for that he went with the 555 because it has one built-in. Three resistors and a capacitor later he’s in business, adding another resistor and a transistor to deal with the load switching. We’ve embedded video of the circuit controlling an LED after the break. This IC ends up in a lot of projects so dig through your parts bin and give this circuit a try.

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Beginner Concepts: Binary-coded Decimal

January 8, 2010 by 13 Comments

A rudimentary understanding of digital logic and simple integrated circuits is critical if you’re ever going to pull off some really gnarly hacks. [Daniel] put together an explanation about the use of 4511 BCD 7-segment drivers. These chips take binary data in and output decimal data to a 7-segment LED display. In short, they can read 0b1001 from input pins and light the numeral ‘9’ on the display. The best part is that you can build this example circuit in the Atanua logic simulator without ordering parts. We love zero-cost learning!

Symmetry For Beginners – The Rubik’s Cube

May 24, 2016 by 13 Comments

Symmetry is everywhere in our natural world. Just take a look at your hands, a butterfly, or a sunflower.  It’s easy to pass off the idea of symmetry and symmetric structures as a simple quirk of existence, and to pay it little mind. If this is your view, I can assure you it will no longer be by the end of this series. If we force ourselves to look beyond the grade school applications of symmetry, we find a world rich in connections via many different types of symmetric identities. One of the most interesting is Gauge Symmetry, which lies at the heart of Quantum Electrodynamics, or QED (we’ll get into this a bit later in the series). Several branches of higher level mathematics study symmetry in detail, allowing a host of sciences, from physics to chemistry,  to view difficult problems and theories from a different perspective.

The subject matter of the ideas explored in symmetry is complicated, and not well known outside of academia and the theoretical sciences. It is the goal of this series of articles to simplify some of the concepts that underpin the study of symmetry, so that the average hacker can gain a basic (and I mean basic) understanding of this fascinating body of knowledge, and put it to use in future projects.  We’ll start things off by taking a look at a machine that has crossed the Hackaday server many times – those nifty Rubik’s Cube solvers. Just how do those things work anyway?

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A Beginner’s Guide To Magnetometers

July 14, 2011 by 9 Comments

magnetometers_for_beginners

The folks over at LoveElectronics recently published an article that explains some of the ins and outs of magnetometers for those who are interested in trying one out, but might not understand how to use them.

A good part of the article focuses specifically on how to manipulate the HMC5883L magnetometer from Honeywell, but a lot of the information can be applied to other makes/brands of compass sensors. They start out discussing in very basic terms how the compass works, then delve into some specifics on how to interface the chip with an Arduino, courtesy of a breakout board that they sell. The breakout board is actually quite simple, so any number of custom iterations could be built for your own testing purposes.

They walk through the use of an HMC5883L-specific Arduino sketch they produced, making it easy for beginners to start getting useful data from the compass units. While a pre-made sketch might seem like a bit of a cop out, it at least gives the curious/motivated beginner a chance to look at some completed code in order to see how things work.

If you are interested in cutting your teeth on some additional beginner concepts, check out these other how-to articles and tutorials.

Learning Electronics Concepts Step By Step

May 8, 2011 by 38 Comments

arduino

We realize that not everyone out there holds a degree in electrical engineering or has the ability to tell NPN transistors apart from PNP transistors by taste alone, so we occasionally like to mention things that appeal to the beginners in the crowd. While there is a clear division between Arduino supporters and detractors, it is hard to deny that the devices have their place, and can be quite useful when exploring certain electronics concepts.

For the supporters out there, [John Boxall] has put together a site jam-packed with Arduino tutorials covering a wide array of concepts and techniques. We have covered his work before in relation to specific topics, but we felt that his site deserved mention as a whole. His tutorials cover some of the most basic concepts such as lighting LEDs with the Arduino, and work their way to more advanced subjects, lesson by lesson.

He is not satisfied with simply introducing a concept and handing out a sketch that does the work. He takes the time to expand on the concepts, giving the reader enough detail to use their new-found knowledge in later projects. If you were to follow his tutorials from beginning to end, you would be exposed to LCD screen control, shift registers, real-time clocks, I2C bus communications, and more. These skills and concepts can be carried on to future projects as well as other micro controllers, making his tutorials a very valuable learning tool worth checking out.