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.

Mineable Minecraft Block

August 29, 2011 by Brian Benchoff 15 Comments

At Hack A Day, we’re pretty big Minecraft fans so you can imagine our interest when we saw [Ben Purdy]’s real-life Minecraft block. The build uses a projector system to display a block onto a cardboard box and reacts to being ‘mined’ just like in the game.

Block animation is handled by a piezo sensor, an Arduino and a Processing sketch. From earlier posts on [Ben’s] blog, we’re going to guess that he used ~~the keystone video projection library~~ his own solution to map the Minecraft block onto the cardboard box. Animation is handled just as in Minecraft – overlaying the breaking animation onto the block and adding some particle effects.

We’ve seen a few Minecraft hacks before, like using it as a 3D design tool, and connecting your redstone CPU to the outside world. [Ben]’s build follows in the tradition of its forebears and is something we really want to try out. Check out the demos after the break.

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BASIC Programming On An Arduino

August 28, 2011 by Brian Benchoff 96 Comments

[Mike] sent in a project he’s been working on – a port of a BASIC interpreter that fits on an Arduino. The code is meant to be a faithful port of Tiny BASIC for the 68000, and true to Tiny BASIC form, it fits in the very limited RAM of the Arduino.

True to Tiny BASIC’s assembler roots, [Mike]’s C port makes extensive use of the “infinitely-abusable” goto statement. Kernighan and Ritchie said themselves, “code involving a goto can alway be written without one” but [Mike] found that using goto left a lot more room available for BASIC code. The BASIC interpreter eats up around 600 bytes in the Arduino RAM, leaving about 1.4 kB for BASIC code. Not much, but more than the lowest-end BASIC Stamp.

[Mike] says he started this project to see how ‘old bearded ones’ conjured up so many impressive programs with a few kB of RAM. Tiny BASIC was originally conceived for the Altair 8800 that shipped with 256 bytes of RAM stock, so it seemed like a perfect fit. Right now, all we know is we’ll be spending the weekend digging through our copies of Dr. Dobb’s Journal.

A Beginner’s Guide To Burning Arduino Bootloaders

August 26, 2011 by Mike Nathan 17 Comments

When it comes to learning about microcontrollers, everyone has to start somewhere. [Lady Ada] recently posted a tutorial on burning the Arduino bootloader to standalone chips for those just getting started with the micro.

The tutorial cites a common situation, where someone is working on a project using an Arduino chip but they don’t want to sacrifice their dev board when just the micro and a few other components would do just fine. A short list of supplies is required, including an Arduino, a proto shield kit, a ZIF socket, and a blank ATmega chip.

The process is probably pretty straightforward and likely familiar to many of you out there. The ZIF socket is soldered to the board and handful of wires are added for powering and programming the new chip. The protoboard is installed on top of the Arduino like any other shield, and using a sketch that [Lady Ada] has made available, the bootloader burning process is a cinch.

It’s a useful tip for newcomers, and definitely a skill that seasoned Arduino users should have under their belts as well.