Day: November 24, 2010

The Quest To Build A Better Stairmaster

November 24, 2010 by 22 Comments

[Eric Feldman] likes to use the Stairmaster in his exercise routine during the winter months. But apparently the exercisers that are designed for mere mortals don’t satisfy his need to climb stairs really, really, quickly. After mastering the upper speed limits of some top-of-the-line equipment he contacted the company asking if there was a way to unlock the software-imposed speed restriction. They laughed at him; a motivation that he used to build his own that is already five times faster. He calls it the Stairmonster, and after being tested at over 500 stairs per minute that name is quite fitting. It’s got a nice interface for choosing an exercise program and recording data from his routines. It uses an AT89C51RD2 along with a quadrature decoder and a heart rate monitor module that talks to a chest strap worn during each session. A 320×240 touchscreen gives feedback on the routine, which is altered to achieve targeted heat rates for optimum results. Nice job [Eric]!

Double The Hertz, Double The Pleasure

November 24, 2010 by 41 Comments

[tinhead] has opened up a Tekway DST1102B oscilloscope and doubled its bandwidth to 200MHz, sharing his work in the eevblog forum. This is great news to anyone who is looking for a faster sampling rate but can’t afford the high-end models. Mind you, for a lot of us even these Hanteks and Tekways are hard to afford but there are more appropriate options for the ramen-dependent hacker.

In the hacking guide [tinhead] includes comprehensive information on the different scopes he originally considered (a Rigol, Atten and UniTrend) before settling on the Tekway, as well as links to regional distributors for the hackable scope. Good quality benchtop units are invaluable for development and troubleshooting, and it pays off to understand their inner workings. It’s heartwarming to know that even the tools of hacking can be hacked.

Building A Bandwidth Meter

November 24, 2010 by 15 Comments

Here’s an analog bandwidth meter made to look like an old pressure gauge. It’s actually new, but the paper showing the graduated scale was stained in a bath of black tea, then dried in an oven to give it an aged appearance. We think it’s quite effective.

The dial itself is a volt meter driven by an Arduino in much the same way as the multimeter clock. Bandwidth data is pulled from a Linux router, filtered down to the target data using ‘grep’, and sent over the serial connection by a Perl script. Since the meter itself is just waiting for serial data, alterations to the router’s scripting make it easy to represent a count of unread emails, tweets, or whatever data your code can scrape.

[Thanks Ben]

Interface Up To 12 Servos Using Arduino

November 24, 2010 by 5 Comments

[Brian] is using an Arduino to control multiple servo motors. This is nothing new and has been happening since the earliest days of Arduino. But rather than develop a project and share it, [Brian] did a fantastic job of making the code scalable, readable, and even explained how the different parts work.

His code listens for serial commands and manipulates the motors accordingly. He wrote a Python script using pyserial which talks to the Arduino. As an example, he uses a joystick to send data for X and Y axes as well as pitch and roll. Want to know how those serial communications work? He explains that in detail. He also outlines the process of scaling up from the 4 servo demo to 12 servos on a standard Arduino. Sounds like it might be time to build your own version of a mouse-controlled Lynxmotion arm using the tools [Brian] has put together.

SparkFun Free Day 2011: Now With Gambling

November 24, 2010 by 52 Comments

SparkFun has just announced a Free Day for 2011. Last year was the first time they decided to give away $100,000 in the form of $100 credits that melted down their servers and made the rest of the world (you know, the non-geek sort) ask what SparkFun was when it started trending on Twitter, Google, and every other form of digital communication.

Well, they’re doing it again this year, albeit quite differently. Mark your calendar for Thursday, January 13th at 9am Mountain Standard Time. But it’s not as simple as having your cart pre-filled and trying to bum rush the checkout pages. Now you’ve got options; take a loyalty payout of $10 for each year that has passed since you registered an account with them, or gamble for a $100 credit. The latter involves answering ten questions, rewarded with $10 for each correct answer and penalized $3 for each wrong answer. If you don’t finish all ten before the money runs out you get zip.

There’s several bits of good news here. First, they just picked up a new rack of servers which should help keep the website from crashing. Secondly, the prize money has been ramped up by %50 to a total of $150,000. And finally, if you choose to answer the trivia questions, $2 is being donated to charity for each correct answer. So study up on your electronic theory and you can help others while trying to help yourself.

[Thanks Diego]

MeggyCade: When Handheld Pixel Gaming Isn’t Enough

November 24, 2010 by 12 Comments

[Bomber Punk] built his own arcade cabinet, but you won’t find any MAME games here. He made the enclosure to house a Meggy Jr. 8×8 pixel graphics game console. Proper coin-op buttons and a joystick replace the stock tactile switches that come with the kit. [Bomber Punk] has also added a lighted coin slot. A three-cell battery pack powers the beast, with a programming port to one side so that different games can be loaded from a PC. We’d like to see a processor upgrade that would allow multiple games to be stored on a stand-alone system.

Take a look at the video after the break, it’ll bring a smile to your face.

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