The Newest Graphing Calculator Game

January 25, 2016 by Bryan Cockfield 7 Comments

Certainly everyone remembers passing time in a boring high school class playing games on a graphing calculator. Whether it was a Mario-esque game, Tetris, or BlockDude, there are plenty of games out there for pretty much all of the graphing calculators that exist. [Christopher], [Tim], and their colleagues from Cemetech took their calculator game a little bit farther than we did, and built something that’ll almost surely disrupt whatever class you’re attempting to pay attention in: They built a graphing calculator whac-a-mole game.

This game isn’t the standard whac-a-mole game, though, and it isn’t played on the calculator’s screen. Instead of phyiscal “moles” the game uses LEDs and light sensors enclosed in a box to emulate the function of the moles. In order to whack a mole, the player only needs to interrupt the light beam which can be done with any physical object. The team made extensive use of the ArTICL library which allows graphing calculators to interface with microcontrollers like the MSP432 that they used, and drove the whole thing with a classic TI-84.

This project is a fun way to show what can be done with a graphing calculator and embedded electronics, and it was a big hit at this past year’s World Maker Faire. Calculators are versatile in other ways as well. We’ve seen them built with open hardware and free software, And we’ve even seen them get their own Wi-Fi.

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Lego Technic Of The Past Eliminates Apple ][ With Arduino And Touchscreen

January 25, 2016 by Gerrit Coetzee 9 Comments

[JAC_101], the Director of Legal Evil Emeritus for LVL1 Hackerspace (don’t ask me, it’s their title system), was challenged to a hacking duel. It all started years ago. The person who is now president of LVL1, visited the space for the first time and brought with her a discarded Apple II controller for Lego bricks which had previously belonged to her father. Excited to test it, the space found that, unfortunately, LVL1’s Apple II wouldn’t boot. An argument ensued, probably some trash talking, and [JAC_101] left with the challenge: Could he build an Arduino interface for the Apple II Lego controller quicker than the hackerspace could fix its Apple II?”

Other things that belonged to people's fathers. — Other things that belonged to people’s fathers.

In the end, a concentrated force by one hacker over two years overcame the collective ADHD of many. He began by opening the interface to look inside, a completely unnecessary step since he found it was already thoroughly documented. Next he forgot about the project for a year. Then he remembered it, and built an interface for an Arduino Uno to hook to the controller and wrote a library for the interface. Realizing that sending serial commands was not in line with the original friendly intention of the device, he added a graphical display to the project; which allowed the user to control the panel with touch. In the end he won the challenge and LVL1 still doesn’t have a working Apple II. We assume some gloating occurred. Some videos of it in action after the break.

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There Is No Spoon; Automatic Self Stirring Mug

January 24, 2016 by Bryan Cockfield 24 Comments

Sometimes it’s helpful to realize the truth that there is no spoon. At least, not with [Ronaldo]’s automatic self-stirring mug. At first it was just a small propeller in the bottom of the mug that turned on by pushing a button in the handle, but this wasn’t as feature-rich as [Ronaldo] hoped it could be, so he decided to see just how deep the automatic beverage-mixing rabbit hole goes.

The first thing to do was to get a microcontroller installed to handle the operation of the motor. The ATtiny13a was perfect for the job since it’s only using one output pin to control the motor, and can be configured to only draw 0.5 microamps in power-saving mode. This ensures a long life for the two AAA batteries that power the microcontroller and the motor.

As far as operation goes, the motor operates in different modes depending on how many times the button in the handle is pushed. It can be on continuously or it can operate at pre-determined intervals for a certain amount of time, making sure to keep the beverage thoroughly mixed for as long as the power lasts. Be sure to check out the video below for a detailed explanation of all of the operating modes. We could certainly see some other possible uses for more interesting beverages as well.

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Man Shoots Lamp

January 24, 2016 by Elliot Williams 13 Comments

What do you get when you mix together all of the stuff that you can get for cheap over eBay with a bit of creativity and some PVC pipe? [Austiwawa] gets a table lamp, remote-controlled by a toy gun, that turns off and falls over when you shoot it. You’ve got to watch the video below the break.

This isn’t a technical hack. Rather it’s a creative use of a bunch of easily available parts, with a little cutting here and snipping there to make it work. For instance, [Austiwawa] took a remote control sender and receiver pair straight off the rack and soldered some wires to extend the LED and fit it inside the toy gun. A relay module controls the lamp, and plugs straight into the Arduino that’s behind everything. Plug and play.

Which is not to say the lamp lacks finesse. We especially like the screw used as an end-of-travel stop for the servo motor, and the nicely fabricated servo bracket made from two Ls. And you can’t beat the fall-over-dead effect. Or can you? Seriously, though, great project [Austiwawa]!

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Cricket Scoreboard Is A Big Win For Novice Hackers

January 24, 2016 by Dan Maloney 14 Comments

The game of cricket boggles most Americans in the same way our football perplexes the rest of the world. We won’t even pretend to understand what a “wicket” or an “over” is, but apparently it’s important enough to keep track of that so an English cricket club decided to build their own electronic scoreboard for their – pitch? Field? Help us out here.

This scoreboard build was undertaken by what team member [Ian] refers to as some “middle-aged blokes from Gloucestershire” with no previous electronics experience. That’s tough enough to deal with, but add to it virtually no budget, a huge physical size for the board, exposure to the elements, and a publicly visible project where failure would be embarrassingly obvious, and this was indeed an intimidating project to even consider. Yet despite the handicaps, they came up with a great rig, with a laser-cut acrylic cover for a professional look. A Raspberry Pi runs the LED segments and allows WiFi connections from a laptop or phone in the stands. They’ve even recently upgraded to solar power for the system.

And we’ll toot our own horn here, since this build was inspired at least in part by a Hackaday post. The builders have a long list of other links that inspired or instructed them, and we think that says something powerful about the hacker community that we’ve all been building – a group with no previous experience manages a major build with the guidance of seasoned hackers. That’s something to feel good about.

Link Trucker Is A Tiny Networking Giant

January 22, 2016 by Elliot Williams 17 Comments

If you’re a networking professional, there are professional tools for verifying that everything’s as it should be on the business end of an Ethernet cable. These professional tools often come along with a professional pricetag. If you’re just trying to wire up a single office, the pro gear can be overkill. Unless you make it yourself on the cheap! And now you can.

[Kristopher Marciniak] designed and built an inexpensive device that verifies the basics:

Is the link up? Is this cable connected?
Can it get a DHCP address?
Can it perform a DNS lookup?
Can it open a webpage?

What’s going on under the hood? A Raspberry Pi, you’d think. A BeagleBoard? Our hearts were warmed to see a throwback to a more civilized age: an ENC28J60 breakout board and an Arduino Uno. That’s right, [Kristopher] replicated a couple-hundred dollar network tester for the price of a few lattes. And by using a pre-made housing, [Kristopher]’s version looks great too. Watch it work in the video just below the break.

Building an embedded network device used to be a lot more work, but it could be done. One of our favorites is still [Ian Lesnet’s] webserver on a business card from way back in 2008 which also used the ENC28J60 Ethernet chip.
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Running Calculus On An Arduino

January 18, 2016 by Will Sweatman 39 Comments

It was Stardate 2267. A mysterious life form known as Redjac possessed the computer system of the USS Enterprise. Being well versed in both computer operations and mathematics, [Spock] instructed the computer to compute pi to the last digit. “…the value of pi is a transcendental figure without resolution” he would say. The task of computing pi presents to the computer an infinite process. The computer would have to work on the task forever, eventually forcing the Redjac out.

Calculus relies on infinite processes. And the Arduino is a (single thread) computer. So the idea of running a calculus function on an Arduino presents a seemingly impossible scenario. In this article, we’re going to explore the idea of using derivative like techniques with a microcontroller. Let us be reminded that the derivative provides an instantaneous rate of change. Getting an instantaneous rate of change when the function is known is easy. However, when you’re working with a microcontroller and varying analog data without a known function, it’s not so easy. Our goal will be to get an average rate of change of the data. And since a microcontroller is many orders of magnitude faster than the rate of change of the incoming data, we can calculate the average rate of change over very small time intervals. Our work will be based on the fact that the average rate of change and instantaneous rate of change are the same over short time intervals.