arduino

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DIY Sound Localization Sensor

May 10, 2011 by 32 Comments

sound_localization_sensor

Sound localization is very popular in law enforcement circles due to its accuracy and ability to quickly separate gunshots from other similar noises. These systems don’t come cheap, and after trying to build one himself, [Fileark] knows why.

He thought it would be neat to build a sound localization sensor based on how the human ear determines a sound’s source. Once he got started however, he realized just how hard it was to do localization just right.

He used an LM324N op-amp as a volume comparator, which he says works decently enough though he figures there are ICs out there that can do a better job. [Fileark] reports that the sound detector works well when the source is within about a foot of the sensors, but performance deteriorates at greater distances. He may consider using an ARM Cortex-M3 as his sound processor if he builds a second version, since the Arudino he used just doesn’t have enough power to sample and run calculations within the 10-50 microsecond window he requires.

Keep reading to see a video of his sound localization sensor in action.

Continue reading “DIY Sound Localization Sensor” →

A Friendly Spiderbot Named Chopsticks

May 9, 2011 by 12 Comments

chopsticks_the_spiderbot

After seeing his fair share of hexapod-style bots on the Internet, [Russell] decided he wanted to build one of his own. One of the downsides to building these robots is the cost. He often saw them constructed from laser cut parts and very expensive servos. Rather than blow hundreds upon hundreds of dollars on the bot, [Russell] decided he could a lightweight bot on the cheap using chopsticks and polymorph modeling plastic.

His octopod robot is aptly called “Chopsticks” and utilizes 28 different servos to control its motions. 24 servos are used for its legs, 3 more are reserved for head movements, while a single additional servo manipulates the robot’s mandibles. The robot’s legs and main structure are composed of chopsticks, while the polymorph is used for feet, servo mounts, and pretty much anywhere else chopsticks just wouldn’t do.

[Russell] even added a set of eye stalks to complete the spider theme, arming them with IR compound eyes for object tracking. The robot is quite interactive as you can see in the video below.

Keep reading to see a video of Chopsticks, or swing by his Let’s Make Robots site if you get a chance – he has a pretty detailed construction journal as well as plenty of videos showing his spider bot in action.

Continue reading “A Friendly Spiderbot Named Chopsticks” →

Learning Electronics Concepts Step By Step

May 8, 2011 by 38 Comments

arduino

We realize that not everyone out there holds a degree in electrical engineering or has the ability to tell NPN transistors apart from PNP transistors by taste alone, so we occasionally like to mention things that appeal to the beginners in the crowd. While there is a clear division between Arduino supporters and detractors, it is hard to deny that the devices have their place, and can be quite useful when exploring certain electronics concepts.

For the supporters out there, [John Boxall] has put together a site jam-packed with Arduino tutorials covering a wide array of concepts and techniques. We have covered his work before in relation to specific topics, but we felt that his site deserved mention as a whole. His tutorials cover some of the most basic concepts such as lighting LEDs with the Arduino, and work their way to more advanced subjects, lesson by lesson.

He is not satisfied with simply introducing a concept and handing out a sketch that does the work. He takes the time to expand on the concepts, giving the reader enough detail to use their new-found knowledge in later projects. If you were to follow his tutorials from beginning to end, you would be exposed to LCD screen control, shift registers, real-time clocks, I2C bus communications, and more. These skills and concepts can be carried on to future projects as well as other micro controllers, making his tutorials a very valuable learning tool worth checking out.

Rebecca Black Running Accessory Also Promotes Running For Everyone Within Earshot

May 7, 2011 by 23 Comments

Last Friday, Friday we caught wind of [gvillenave]’s running accessory inspired by Rebecca Black, and we we we so excited, we so excited to bring this to you on Saturday, which comes after Friday.

[gvillenave] came up with the idea of using a song on the annoyance level of “Friday” to encourage a runner into keeping up a good pace. The concept is simple: if the wearer is running fast, the song will speed up. If the wearer is slowing down, the song will slow down and extend the agony.

The build uses an Arduino and [ladyada]’s wave shield coupled to an accelerometer. [gvillenave] included the code, and also wired up some LEDs to a pair of sunglasses that blink more often as the runner’s speed increases. The wave shield has a 3.5mm jack for headphones, but [gvillenave] graciously wired a speaker in, “so that you can annoy people around you, and not just yourself.” All this is packaged in a very nice 3D printed enclosure making for a great looking project.

There’s no word on the effectiveness of the negative reinforcement aspect of [gvillenave]’s build, but we suspect it will help her get down to the bus stop a little faster every morning.

Automate Repetitive PC Actions With A Foot Pedal

May 5, 2011 by 41 Comments

foot_pedal

Instructables user [bkovac] was sick of clicking the terminal icon on his desktop whenever he wanted to launch a terminal window. Keyboard shortcuts aside, he figured the easiest way to take the tedium out of the process would be to launch terminal windows with a foot pedal.

He grabbed a pedal that he had sitting around in his workshop and took it apart to ensure the switch contacts were configured for his particular use. The wires were run to an Arduino which talks to the computer over serial using a Python script.

While the setup works just fine, it’s definitely not the most efficient or simplest way of getting the job done. In fact, we have seen other methods that are quite a bit simpler, though they lack the potential versatility of this particular modification.

Rather than simply loading a terminal window on his computer, we would love to see this pedal enhanced to perform multiple functions – at which point the Arduino would be a pretty decent choice. We would probably start out by swapping out the full-sized Arduino for a Teensy, mounting it inside the pedal. Multiple foot presses could be used to trigger different events, based upon the number of presses that occur within a given time period. It could be made even more useful by using it to trigger gesture-based events, similar to those seen in plug-ins for Chrome and Firefox.

How would you enhance [bkovac’s] pedal interface? Let us know in the comments.

Real-time Robotic Arm Control With Blender

May 4, 2011 by 13 Comments

robotic_arm

Last year, [Justin Dailey] was coming down the home stretch of his senior year as a Computer Engineering student and needed to build a final design project. He always wanted to construct a robotic arm, and figured that there was no better way to legitimize such a project, than to claim that it was “homework”.

While he originally wanted to control the arm with a joystick, he had been messing with Blender quite a bit leading up to his final project, and thought it would be pretty cool to let Blender do the work. He started out by testing his ability to control a single servo with Blender, then slowly increased the complexity of the project. He prototyped the arm using cardboard, and satisfied with his progress thus far, began constructing the arm out of aluminum.

Once he had all six of his servos attached to the arm’s joints and wired to his Roboduino, he got busy constructing a 3D model in Blender. Using a few Python scripts, the movements inside Blender are translated to serial data in real-time, which is relayed to the Roboduino in order to control the arm.

Check out his site if you get a chance – there’s plenty of code to be had, as well as several videos of the arm in various stages of construction and testing.

Large Remote-controlled Game Of Life Display

May 3, 2011 by 5 Comments

game_of_life

Sometimes it’s just plain fun to over-engineer. [Stephanie] gets a warm fuzzy feeling when she successfully adds way more electronics components to a project than she really needs – just because she can. We can’t really argue with her if that is the intended goal, nor can we find fault with the sweet Game of Life display she put together.

She started off with six Game of Life kits from Adafruit, but she quickly caught the LED bug and her collection grew until she had 20 kits (that’s 320 LEDs for those of you keeping count). After piecing them all together, they were mounted in a wooden frame and placed behind a dark piece of acrylic. It looked great and worked just fine, but it wasn’t overdone enough for her tastes.

In the end, she added a small Arduino and Xbee module to the Game of Life display, which enables it to be controlled by her network-enabled thermostat we featured a few weeks back. The thermostat was fitted with an Xbee unit as well, which allows it to turn the Game of Life on and off at whatever times [Stephanie] specifies.

We’ll take two please.

[via Adafruit Blog]