Carol Willing Wins the CC Code Challenge (Week 17)

We have a winner of last week’s CC Weekly Code Challenge, sponsored by IAR Systems! We posted a code snippet with an error and challenged the engineering community to find the mistake!

Congratulations to Carol Willing of Encinitas, California, USA for winning the CC Weekly Code Challenge for Week 17! Carol will receive an Elektor 2012 & 2011 Archive DVD.

Carol’s correct answer was randomly selected from the pool of responses that correctly identified an error in the code. Carol answered:

Line 6: cons will incorrectly create a list of lists; use append instead for correct recursive reversal of list

2013_code_challenge_17_answer

You can see the complete list of weekly winners and code challenges here.

What is the CC Weekly Code Challenge?
Each week, Circuit Cellar’s technical editors purposely insert an error in a snippet of code. It could be a semantic error, a syntax error, a design error, a spelling error, or another bug the editors slip in. You are challenged to find the error.Once the submission deadline passes, Circuit Cellar will randomly select one winner from the group of respondents who submit the correct answer.

Inspired? Want to try this week’s challenge? Get started!

Submission Deadline: The deadline for each week’s challenge is Sunday, 12 PM EST. Refer to the Rules, Terms & Conditions for information about eligibility and prizes.

Website Maintenance Progress

We’d like to thank our members and readers around the globe for their patience while our sites were down for maintenance. During the past few days, our team has been working on building a better site to deliver you the quality informative content you’ve come to expect. Today, we’re happy to announce most of the site is up and the article materials are available. Please bare with us as we complete the final steps in the process.

Are you social? Connect with us!

Thank you!

Regards,

The CC Team

William McNamara Wins the CC Code Challenge (Week 16)

We have a winner of last week’s CC Weekly Code Challenge, sponsored by IAR Systems! We posted a code snippet with an error and challenged the engineering community to find the mistake!

Congratulations to William McNamara of The Colony, Texas, USA for winning the CC Weekly Code Challenge for Week 16! William will receive a CC T-Shirt and one year digital subscription/renewal.

William’s correct answer was randomly selected from the pool of responses that correctly identified an error in the code. William answered:

Line 5: the “do” needs to be on a separate line or have a semicolon in front of it.

2013_code_challenge_16_answer

You can see the complete list of weekly winners and code challenges here.

What is the CC Weekly Code Challenge?
Each week, Circuit Cellar’s technical editors purposely insert an error in a snippet of code. It could be a semantic error, a syntax error, a design error, a spelling error, or another bug the editors slip in. You are challenged to find the error.Once the submission deadline passes, Circuit Cellar will randomly select one winner from the group of respondents who submit the correct answer.

Inspired? Want to try this week’s challenge? Get started!

Submission Deadline: The deadline for each week’s challenge is Sunday, 12 PM EST. Refer to the Rules, Terms & Conditions for information about eligibility and prizes.

CC279: What’s Ahead in the October Issue

Although we’re still in September, it’s not too early to be looking forward to the October issue already available online.

The theme of the issue is signal processing, and contributor Devlin Gualtieri offers an interesting take on that topic.

Gualtieiri, who writes a science and technology blog, looks at how to improve Improvig Microprocessor Audio microprocessor audio.

“We’re immersed in a world of beeps and boops,” Gualtieri says. “Every digital knick-knack we own, from cell phones to microwave ovens, seeks to attract our attention.”

“Many simple microprocessor circuits need to generate one, or several, audio alert signals,” he adds. “The designer usually uses an easily programmed square wave voltage as an output pin that feeds a simple piezoelectric speaker element. It works, but it sounds awful. How can microprocessor audio be improved in some simple ways?”

Gualtieri’s article explains how analog circuitry and sine waves are often a better option than digital circuitry and square waves for audio alert signals.

Another article that touches on signal processing is columnist Colin Flynn’s look at advanced methods of debugging an FPGA design. It’s the debut of his new column Programmable Logic in Practice.

“This first article introduces the use of integrated logic analyzers, which provide an internal view of your running hardware,” O’Flynn says. “My next article will continue this topic and show you how hardware co-simulation enables you to seamlessly split the verification between real hardware interfacing to external devices and simulated hardware on your computer.”

You can find videos and other material that complement Colin’s articles on his website.

Another October issue highlight is a real prize-winner. The issue features the first installment of a two-part series on the SunSeeker Solar Array Tracker, which won third SunSeekerplace in the 2012 DesignSpark chipKit challenge overseen by Circuit Cellar.

The SunSeeker, designed by Canadian Graig Pearen, uses a Microchip Technology chipKIT Max32 and tracks, monitors, and adjusts PV arrays based on weather and sky conditions. It measures PV and air temperature, compiles statistics, and communicates with a local server that enables the SunSeeker to facilitate software algorithm development. Diagnostic software monitors the design’s motors to show both movement and position.

Pearen, semi-retired from the telecommunications industry and a part-time solar technician, is still refining his original design.

“Over the next two to three years of development and field testing, I plan for it to evolve into a full-featured ‘bells-and-whistles’ solar array tracker,” Pearen says. “I added a few enhancements as the software evolved, but I will develop most of the additional features later.”

Walter Krawec, a PhD student studying Computer Science at the Stevens Institute of Technology in Hoboken, NJ, wraps up his two-part series on “Experiments in Developmental Robotics.”

In Part 1, he introduced readers to the basics of artificial neural networks (ANNs) in robots and outlined an architecture for a robot’s evolving neural network, short-term memory system, and simple reflexes and instincts. In Part 2, Krawec discusses the reflex and instinct system that rewards an ENN.

“I’ll also explain the ‘decision path’ system, which rewards/penalizes chains of actions,” he says. “Finally, I’ll describe the experiments we’ve run demonstrating this architecture in a simulated environment.”

Videos of some of Krawec’s robot simulations can be found on his website.

Speaking of robotics, in this issue columnist Jeff Bachiochi introduces readers to the free robot control programming language RobotBASIC and explains how to use it with an integrated simulator for robot communication.

Other columnists also take on a number of very practical subjects. Robert Lacoste explains how inexpensive bipolar junction transistors (BJTs) can be helpful in many designs and outlines how to use one to build an amplifier.

George Novacek, who has found that the cost of battery packs account for half the DIY Battery Chargerpurchase price of his equipment, explains how to build a back-up power source with a lead-acid battery and a charger.

“Building a good battery charger is easy these days because there are many ICs specifically designed for battery chargers,” he says.

Columnist Bob Japenga begins a new series looking at file systems available on Linux for embedded systems.

“Although you could build a Linux system without a file system, most Linux systems will have some sort of file system,” Japenga says. “And there are various types. There are files systems that do not retain their data (volatile) across power outages (i.e., RAM drives). There are nonvolatile read-only file systems that cannot be changed (e.g., CRAMFS). And there are nonvolatile read/write file systems.”

Linux provides all three types of file systems, Japenga says, and his series will address all of them.

Finally, the magazine offers some special features, including an interview with Alenka Zajić, who teaches signal processing and electromagnetics at Georgia Institute of Technology’s School of Electrical and Computer Engineering. Also, two North Carolina State University researchers write about advances in 3-D liquid metal printing and possible applications such as electrical wires that can “heal” themselves after being severed.

For more, check out the Circuit Cellar’s October issue.

 

 

Jesper Poulsen Wins the CC Code Challenge (Week 15)

We have a winner of last week’s CC Weekly Code Challenge, sponsored by IAR Systems! We posted a code snippet with an error and challenged the engineering community to find the mistake!

Congratulations to Jesper Poulsen of København, Denmark for winning the CC Weekly Code Challenge for Week 15! Jesper will receive a CCGold Issues Archive.

Jesper’s correct answer was randomly selected from the pool of responses that correctly identified an error in the code. Jesper answered:

Line 23: Should be 0..@list-2 to avoid array overrun when taking $list[$i+1]

2013_code_challenge_15_answer

You can see the complete list of weekly winners and code challenges here.

What is the CC Weekly Code Challenge?
Each week, Circuit Cellar’s technical editors purposely insert an error in a snippet of code. It could be a semantic error, a syntax error, a design error, a spelling error, or another bug the editors slip in. You are challenged to find the error.Once the submission deadline passes, Circuit Cellar will randomly select one winner from the group of respondents who submit the correct answer.

Inspired? Want to try this week’s challenge? Get started!

Submission Deadline: The deadline for each week’s challenge is Sunday, 12 PM ESTRefer to the Rules, Terms & Conditions for information about eligibility and prizes.