Security System Gives You A Call When It Senses Intruders

gsm_motion_detector_alarm_system

[Dimitris] decided to build a homemade alarm system, but instead of triggering a siren, sending an SMS message, or Tweeting about an intrusion, he preferred that his system call him when there was trouble afoot. He says that he preferred a call over text messaging because there are no charges associated with the call if the recipient does not pick up the line, which is not the case with SMS.

The system is based around an off the shelf motion detector that was hacked to work with an old mobile phone. The motion detector originally triggered a siren, but he stripped out the speaker and wired it to a bare bones Arduino board he constructed. The Arduino was in turn connected to the serial port of an unused Ericssson T10s mobile phone. This allows the Arduino to call his mobile phone whenever the motion detector senses movement.

The system looks to be quite useful, and while [Dimitris] didn’t include all of the code he used, he says others should be able to replicate his work without too much trouble.

GPS Audio Tour Brought To You By Surface Speakers

The team at Eschelle Inconnue wanted to “trace a sound cartography of Islam” in Marseilles, France, so they came up with a clever little GPS walking tour powered by an Arduino, MP3 playback module, and a surface transducer speaker.

The team used a Processing app to define geographic areas where each MP3 file would play. An Arduino on the build queries a GPS module and selects the audio file from an MP3 playback module. This isn’t uncommon, and a lot of large outdoor museums (think battlefields) have similar setups.

Determining which audio to play at what location is fairly easy, but that’s not what makes this build special. Instead of simply hooking up a pair of headphones to the build, the team decided to use a surface speaker that turns just about any solid material into a speaker. From the writeup, this is supposed to, “diffuse sounds by giving the illusion to collect them, to listen to the words of the walls, the whisperings through the materials” but we think it’s just a great way to have several people listen to the same audio file at the same time.

Upgrading RAM In An Arduino Mega

[Andy] stuffed some more RAM onto an Arduino Mega and his three-part walk through on the design, construction, and software is a great read and one of the more ‘hard core’ Arduino builds we’ve seen.

The build is centered around a 512K × 8 SRAM module [PDF warning]. Because the RAM is divided up into about 512,000 chunks of 8 bits, the Arduino has to access the RAM through 16 ‘address lines’, then send the data through 8 ‘data lines’. [Andy] didn’t want to use up 24 pins on his Arduino, so he used a latch to multiplex the lowest 8 address lines and the data lines together. With the 512KB RAM expansion installed, the Mega is able to address a whopping 520 Kilobytes.

We’ve seen a few builds that have been limited by the amount of RAM available in the Arduino, like capturing video and some robot hacks, and adding some more RAM to those builds would be great. Multiplexing data and address lines using a latch can be expanded even further, but 520KB ought to be enough for anybody.

Awesome Fiber Optic LED Viking Helmet

octobrite_led_mohawk_helmet

[Garrett] over at MaceTech was approached by a friend who needed a light-up mohawk installed on a Viking helmet, and he needed it ASAP.

Now, [Garrett] does tons of work with LEDs but it’s not every day you are asked to construct a sound-responsive LED mohawk. He had all sorts of LEDs and other bits on hand, but finding the fiber optics that would make up the mohawk itself took a bit of time.

After a bit of searching, he located some cheap bulk fiber optic toy wands, and got busy cutting them apart to remove the fiber bundles. The fibers were glued into a laser cut plastic assembly, where they were paired with a handful of OctoBrite CYANEA modules [Garrett] had on hand. He bought a handful of components from SparkFun, including an Arduino Pro Mini to control the device, as well as an electret mic and graphic equalizer chip to handle the audio input/filtering.

He wrapped up the code portion of the mohawk and handed it off to his friend, who says that the “helmet is +99 to epic awesomeness”, which sounds like a ringing endorsement to us.

[via BuildLounge]

Check out the video below to see the fiber optic mohawk helmet in action.

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Robust Wireless DSLR Control Over Bluetooth

yanis_android_bluetooth_camera_controller

[Manishi] wrote in to share his latest project, a Bluetooth DSLR controller that works with Android. More than a mere Bluetooth shutter trigger, his device lets you control a wide array of other settings such as aperture, shutter speed, ISO, white balance, focus position and live view.

His “YaNis” control system was built using an Arduino Pro Mini, along with a USB host shield and a Bluetooth module he picked up from SparkFun. Obviously any other Arduino and SPP compatible Bluetooth board can be used, though component size is definitely a consideration for this project, and his selections are pretty well-suited to the job. The Arduino half of the software relies heavily on [Oleg Maruzov’s] PTP/USB libraries to get things done, but the free Android control app is all [Manishi’s] creation.

The Bluetooth dongle connects to the camera via USB, and once it’s paired with his Android phone, [Manishi] has total control at his fingertips. He has plenty of improvements planned for the near future including additional camera support, so we expect that we’ll see an even more robust control application before too long.

Continue reading to see a quick video demo of YaNis in action.

Continue reading “Robust Wireless DSLR Control Over Bluetooth”

Insects Turned Into Orchestra; Not Harmed But Terribly Inconvenienced

[Jochem] has always been fascinated by chaos in nature, whether it’s a swarm of ants or evolution in action in a petri dish. His insect orchestra takes the chaos in the natural world and changes it into something completely artificial. In this case, MIDI.

For the build, a light sensor was placed at the bottom of a test tube. A cricket (or grasshopper, or locust) is then put into the test tube. The test tube is then closed up with a cap that houses a LED. An Arduino reads the light sensors and then transmits the data over MIDI. The MIDI commands are picked up in Abelton Live which converts everything to audio.

[Jochem] rigged up Abelton to have the insects perform in four different modes – instrument, synthesis, samples, and drums. Definitely an improvement over the humble Mexican Jumping bean.

You can check out the insect orchestra in action after the break.

Continue reading “Insects Turned Into Orchestra; Not Harmed But Terribly Inconvenienced”

Monitoring Water Levels With A Parallax Ping Sensor

arduino_parallax_ping_water_level_sensor

When you need a mechanism to detect the water level within a container or tank, you have several different options. Most people opt for a simple float or probe that sits in the water, while others use optics to sense when the water is reaching an undesired level.

This device built by [Danilo Abbasciano] uses a Parallax Ping sensor instead. If the sensor is placed at the top of a well, cistern, or other water container, it can accurately calculate the height and volume of the fluid inside. This is done by using the Ping’s readings in conjunction with a few values already known to the user, namely the dimensions of the container.

In his implementation, the readings are relayed to a simple LCD panel for easy viewing, and a small piezo speaker is used to sound an alarm when the water level reaches a predefined threshold. This sort of measuring device can be quite useful in situations where a contact-based sensor would be subject to chemicals and corrosion, or where contamination is a concern.