Use FPGAs The Easy Way With Alien Cortex AV

alien_cortex_av_fpga_board

Hackaday reader [Louis] wrote in to call our attention to a neat project over at Kickstarter that he thought would interest his fellow readers. The AlienCortex AV is a pre-built FPGA board from [Bryan Pape] with gobs of ports and a ton of potential. At the heart of the board is an Xilinx PQ208 Spartan 3e 500k FPGA, which can be configured to perform any number of functions. The board sports a healthy dose of analog and digital I/O pins as you would expect, along with PS/2 inputs, VGA outputs, and even a pair of Atari-compatible joystick ports.

The AlienCortex software package allows users to easily load projects into the FPGA, which can run up to four different emulated microcontrollers at once. The software comes with half a dozen pre-configured cores out of the box, with others available for download as they are built. The default set of cores includes everything from a 32-channel logic analyzer, to a quad processor Arduino-sketch compatible machine.

Now, before you cry foul at the fact that he’s emulating Arduinos on a powerful and expensive FPGA, there’s nothing stopping you from creating an army of whatever microcontrollers you happen to prefer instead. We’re guessing that if you can run four Arduinos on this board at once, a good number of PICs could be emulated simultaneously alongside whatever other uC you might need in your next robotics project. A single board incorporating several different microcontrollers at once doesn’t sound half bad to us.

24 Cellphone Buttons Controlled With 6 Microcontroller Pins

[J8g8j] has been playing around with an old cellphone. He wanted to control it using a microcontroller but since there’s 24 buttons he wasn’t thrilled about hooking up a couple dozen relays to do the switching. Instead, he managed to control all 24-buttons using just 6-pins of a microcontroller.

The proof-of-concept video that he posted on his site shows the phone responding to an arbitrary string of button presses. [J8g8j] spent the majority of his time reverse engineering how the phone’s keypad is wired. Once he figured out the rows and columns of the key matrix he soldered wires to access each of them. This turns out to be 14 connections. To these, he wired up a set of opto-isolators to handle the switching. These are in turn controlled by a set of three 74HC138A 3-8 bit decoders. what’s left are six input pins that leave plenty of room for him to hook up other items to the Arduino serving as the microcontroller.

Twitter Notifier Lets Us Know How Awesome We Are

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Let’s admit it, you’re just a little bit vain. Heck, we’re all just a little bit vain when you really think about it. Instructables user [pdxnat] was self-absorbed enough that he constructed an LED “mood light” that alerts him each time someone mentions his user name on Twitter.

The build is pretty simple, with most of the work being done on his PC. His Arduino is wired to a simple RGB LED that calmly cycles through various colors until someone mentions his name on Twitter. At that point, the client software running on his PC passes a message to the Arduino over a serial interface, causing it to wildly pulse the LED. Once it catches his eye, he stops the alert cycle with the press of the reset button, returning the LED to its previous state. As a bonus, he decided to write the Twitter-polling application in both Processing and Python, enabling fans of either language to easily replicate his work.

It’s a pretty cool idea, and it would be great to see someone expand it to include other online services to provide a greater overall feel for how awesome they really are.

Keep reading to see a quick video of the notifier in action.

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Beginner Concepts: Using A Low-pass Filter To Smooth PWM Output

Microcontrollers are digital devices at heart. They can do fancy things like convert analog signals into a digital value but going the other direction is a bit tougher. Pulse-Width Modulation is used to approximate an analog output but what you’re actually doing is turning the operating voltage on and off very quickly to achieve an average value somewhere in between. This is the method most commonly used to dim an LED. But generating a smooth voltage in this way takes just a few more parts.

[Scott Daniels] spent some time discussing the process of smoothing a PWM output by using a low pass filter. This is a compilation of digital and analog circuitry to produce a smoother signal than PWM can achieve on its own. As you can see above, the low pass filter is made up of one resistor and one capacitor. The theory is not hard to understand, and with [Scott’s] help you’ll become much more comfortable with choosing the component values for your own filters. His examples center around an Arduino using the analogWrite() function but the techniques can be applied universally.

An Instrument That Plays Along With You

muse

The crew over at Teague Labs was talking about musical instruments and how digital music creation seems to get bogged down under user interfaces littered with increasing numbers of buttons, knobs, and sliders. They decided to build a musical device that has its own musical inclinations and personality, while also allowing for two-way interaction with the user.

The resulting creation is Muze, a simple musical instrument with only a single user input. Muze has been programmed with a palette of notes that it can combine and remix into a nearly infinite number of musical combinations. Muze is perfectly happy composing on its own, and will create music that evolves over time, if left alone long enough.

As with all musicians, not every tune is a hit, so Muze can be gently nudged away from cacophonous melodies with a simple twist of a knob. Each of the device’s knobs represent a blend of functions, which are used to influence Muze when placed on the board. The interaction does not send Muze flying into a completely different direction, rather it tells Muze to shake things up a little bit, much like you would ask your guitarist to pick up the tempo during a jam session.

It’s a neat little instrument, and we can imagine it would be a big hit with kids and adults alike. Keep reading to see a video demonstration of Muze in action.

Continue reading “An Instrument That Plays Along With You”

Modifying A Cheap Robot Arm For Arduino Control

Many a hacker has put together one of those cheap $30 robot arm kits you can get in just about any store with a section labeled, “science”.  In an ongoing search for a cheap robot arm, [Larry] decided to modify one of them to be controlled with a PC through an Arduino. The article doubles as a really basic tutorial on dc motor control. On the site he gives a brief explanation of how to use H-bridges and a good explanation of how he wired them up for this purpose. He eventually goes on to add a processing interface to the project. The next step would be figuring out how to add some kind of position feedback, such as encoders. Though, if modifying an arm is not your style, [Larry] has another cool article on rolling your own robot arm cheaply with some foam board and hobby servos.

MIT’s ESuperbike Takes On The Isle Of Man

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While the Isle of Man typically plays host to an array of gas-powered superbikes screaming through villages and mountain passes at unbelievable speeds, the island’s TT Race is a bit different. Introduced in 2009 to offer a greener alternative to the traditional motorcycle race, organizers opened up the course to electric bikes of all kinds. In order to entice participants, they even put a £10k prize on the line for the first bike that completes the race with an average speed of 100 miles per hour or faster. While no one has claimed the prize just yet, that didn’t stop the MIT Electric Vehicle team from tossing their hat into the ring this year.

Their entry into the race is the brainchild of PhD student [Lennon Rodgers] and his team of undergrads. They first designed a rough model of the motorcycle they wanted to build in CAD, and through a professor at MIT sourced some custom-made batteries for their bike. Through a series of fortunate events, the team found themselves in front of BMW management, who donated an S1000RR racing bike to the project. After a good number of alterations, including the addition of an Arduino to control the bike, they were ready for race day.

While the team didn’t take the checkered flag, they did finish the race in 4th place. Their bike managed to complete the course with an average speed of 79 mph, which isn’t bad according to [Rodgers]. He says that for their first time out, he’s happy that they finished at all, which is not something every team can claim.