Upgrading RAM In An Arduino Mega

September 5, 2011 by Brian Benchoff 24 Comments

[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.

Material Of Choice: Felt Pen On Glass

September 4, 2011 by Mike Szczys 20 Comments

If you’re paying big bucks for those floor-to-ceiling windows why not make them into a canvas for your art as well. Der Kritzler is a motorized plotter that can make this into a reality. It’s a laser-cut pen holder suspended from a pair belt pulleys. Those belts have counterweights, which make it easier for the stepper motors to move the pen jig smoothly. The firmware running on the Arduino that controls Der Kritzler has some very precise setup requirements. Since there is no feedback for the Arduino to sense the position of the pen, the two stepper motors must be exactly 1500 mm apart with 1060mm of toothed belt between the carriage and each stepper motor when the power is turned on.

Input images are converted to code for the device using a processing sketch. So far [Alex] has tried out a couple of different effects, starting with a vector graphic, or using some open source tools to convert bitmaps to vector graphics. Don’t miss his video demonstration embedded after the break.

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Awesome Fiber Optic LED Viking Helmet

September 1, 2011 by Mike Nathan 28 Comments

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

September 1, 2011 by Mike Nathan 4 Comments

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.

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Bare-bones Electronic Advent Calendar

August 31, 2011 by Brian Benchoff 13 Comments

It’s officially September now (in some parts of the world), and that means we’ve been watching the Christmas decorations go up on the floor of Costco, Walmart and Target for the last few weeks. As a small test of reality, [Eric] decided to build an electronic advent calendar that counts down the days until Christmas. As a simple build using parts lying around on the bench, [Eric] did a pretty good job at deferring his kid’s questions of, “How long until Christmas?” to a machine.

The build is fairly bare-bones, using only an Arduino Pro Mini, RTC and LCD display. For the real-time clock, [Eric] used the ever popular DS3231 RTC. The software reads the time from the clock and calculates the number of seconds between the present time and the hard-coded target date.

Everything is powered by a 9 Volt battery that wouldn’t last the remaining 115 days until Christmas. There is a power switch and the RTC has a battery backup, so the build will probably suffice for all but the most fanatical child.

Insects Turned Into Orchestra; Not Harmed But Terribly Inconvenienced

August 31, 2011 by Brian Benchoff 28 Comments

[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.

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Monitoring Water Levels With A Parallax Ping Sensor

August 30, 2011 by Mike Nathan 18 Comments

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.