CC Code Challenge (Week 8) Stumps Engineering Community

We stumped the engineering community with last week’s CC Weekly Code Challenge! We posted a code snippet with an error and challenged you to find the mistake!

Since nobody had the correct answer, we’ve drawn one lucky winner at random from all those who participated.

Congratulations to Marcelo Jimenez of Rio de Janeiro, Brazil for being selected in the CC Weekly Code Challenge – Week 7 drawing! He’ll receive a CC Tag Cloud t-shirt.

The language is Burroughs Corporation “Enhanced” Algol, a rather obscure language these days, though Algol variants were important in their time and are still discussed today in terms of their influence on the structure of subsequent programming languages. The correct answer was: Line 4: incorrect exponent character – it should be “2.99792458@8″

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.

Great Plains Super Launch 2013

 

Pella, IA — Spectators, visitors and participants alike all erupted into cheerful applause and exclamation after watching the weather balloons launch successfully from the launch site at Vermeer on Saturday. The onlookers observed these hydrogen/helium filled balloons rising into the air until they faded from sight, approaching extremely high altitudes.  The launch was the start of an hour and a half that the balloon spent ascending, all the way into the Earth’s ozone layer.  Another thirty five or forty minutes later the balloon popped and parachutes back to Earth.

The balloons enable us to explore the region of the atmosphere called “near space”, which is above 60,000 ft., but below the accepted altitude of space- 328,000 ft. Cosmic radiation of near space is 100 times greater than it is at sea level. The large balloons are attached to a payload, which contains GPS tracking and various sensors. The payloads contain beacons which emit radio signals. Many of the payloads in this year’s super launch were made by students dedicated to exploring near space.

This sort of active involvement is what PENS strives for. PENS is Pella’s Exploring Near Space program. Mike Morgan, the president of PENS, enjoys and commits to getting kids involved and interested in science and technologies.

“The only thing that goes higher than our balloons are astronauts and satellites. The launch of a radio balloon isn’t something you see or do every day,” Morgan said.
The payload of the balloon also includes a camera so that you can get the view from the edge of space, along with other valuable information that the payload and sensors give. They are used to test things such as barometer, pressure, temperature, UV radiation and humidity. All of these are important factors in the study of aero science.

Bill Brown, founding father of Amateur Radio, participated in the Great Plains Super Launch on Saturday. From Alabama, Brown flew the first high altitude balloon with an amateur radio and video camera in 1987. Brown has flown 400 balloons in 20 states, but each launch presents new information and stimulating challenges. Brown explains that from the edge of space, “You can see the black sky and the curve of the Earth”.

For Nick Stich, the balloon that he launched was his 188th balloon. Balloons from all over the country were launched last Saturday, including radio balloons from Nebraska Stratospheric Amateur Radio, Edge of Space Sciences, DePauw University, and Iowa High Altitude Balloon. PENS, coordinated by Jim Emmert, hosted the conference for near space explorers and enthusiasts.

By Renee Van Roekel
The Chronicle

For more information on the super launch or radio ballooning, visit www.superlaunch.org .

This article was originally published by The Pella Chronicle on June 22, 2013, and is posted here with the permission of its publisher.

Elektor’s Electronics Lab

Want to share electronics projects? Looking for a design community that will help you reach your project goals? Need feedback on your electronic system-related ideas, applications, and design plans?

ELektor.LABS is for you!

Current projects in Elektor.LABS:

  • PLµX: Programmable Logic Microcontroller on Linux
  • Wireless Batter Charger
  • LPC810 as NE555 or as Capacitance Meter
  • FPGA Development Board
  • USB-IO24 Cable
  • Wi-Fi RGB LED Strip
  • And many more!

Want to know more? Check out this video.

CircuitCellar.com is an Elektor International Media publication.

CC 277: Simulate and Design a Switched Capacitor Filter

Here is Lacoste’s experimental mockup. It’s not pretty, but it’s functional. The clock is at the top. The filter is below.

Circuit Cellar columnist Robert Lacoste doesn’t like to throw away his old magazines—at least the ones that have electronics projects.

And often it’s the lack of microcontrollers in such projects that he finds intriguing. The designs required “clever solutions to implement even simple features, which is always a good source of inspiration,” he says.

Lacoste was recently inspired by a 1981 Elektor magazine article on switched-capacitor filters (part of the old magazine collection in his basement). So, he decided to revisit the topic in his column appearing in Circuit Cellar’s August issue.

“I figured, why not refresh it for a Circuit Cellar Darker Side article, as mastering switched-capacitor filters is now mandatory for plenty of mixed-signal designs?”

Lacoste’s column shows you how to modify a basic low-pass filter into a switched-capacitor filter.

He explains why such a modification can be a good one:

“The most basic form of a low-pass filter is the simple one-pole RC filter… Why can’t we be happy with such simple RC filters? There are two reasons. First, it is often convenient to have a filter with an adjustable cutoff frequency. With a RC filter, you would need to change either the resistor’s or the capacitor’s value. This it is not easy to do if you want to design an inexpensive electronic system. The other reason is more linked to IC technology and CMOS in particular.

“Assume you want to design a filtering chip with a cutoff frequency of about 10 kHz. If you want to use a small and inexpensive capacitor—perhaps no more than 1 nF—you will need a high-value resistor… The problem is that designing a high-value resistor on a silicon chip is complicated (i.e., expensive). Moreover, unlike capacitors, on-chip resistors are difficult to manufacture with tight specifications.”

Lacoste found the solution by looking through few back issues of his magazine collection and a few past decades.

“In the late 1970s, IC designers looked for a way to replace high-value resistors with inexpensive and easy-to-integrate parts (e.g., small capacitor),” he says.

The idea of replacing a resistor with a switched capacitor produced the switched-capacitor architecture Lacoste presents in his August column. As a bonus, his design offers an easy way to adjust switching frequencies.

“Of course, no one is actually designing a switched-capacitor circuit from scratch, as I did for this article,” Lacoste says. “It was only for demonstration purposes. There are plenty of ready-made switched-capacitor chips on the market. Just read their datasheets and use them in your design, more or less as a black box.”

Still, Lacoste says, “the best way to learn is to never be afraid of any technology. Knowing the internals helps you avoid usage mistakes.”

Intrigued? Check out Lacoste’s column in the August issue for more details.

Alex Ivopol Wins the CC Code Challenge (Week 7)

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 Alex Ivopol of Wellington, New Zealand for winning the CC Weekly Code Challenge for Week 7! He’ll receive an IAR Kickstart KSK-TMPM061-JL kit.

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

2013_code_challenge_07_answerYou 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.