Swisscopter: single-seat helicopter with H2O2 rockets on tip of rotor 
Monday, March 29, 2010, 01:09 AM - Flying Contraptions
Swisscopter AG has a couple demo videos of a single seat ultra-light helicopter that is powered by H2O2 rockets on the tip of its main rotor. The advantage of the design is the quasi-absence of moving parts, and the absence of a torque on the body.

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Using Android phones to control robots 
Monday, March 29, 2010, 12:56 AM - Robotics
Several projects are underway to couple an Android phone with an Arduino so as to control robots. After all, Android phones have a powerful CPU, a camera, accelerometers, a magnetometer, and a GPS, everything you need for a nice robotic platform in a small form factor. The only problem is getting the phone to send control signals. On certain phones, this can be done with a serial port, on most others, this can be done through BlueTooth.

- Cellbot
- Firmata: Android <-> Arduino via Bluetooth
- Amarino: Android <-> Arduino via Bluetooth
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One Week with a Nexus One Google Phone 
Monday, March 29, 2010, 12:27 AM - Electronics
As soon as Google announced the availability of a version of the Nexus One phone that works with AT&T's 3G frequencies, I got one ($530 direct from Google). This is the best phone every made by a long shot. Waaaay better than the iPhone.
The 800x480 OLED display is fantastic. With 800 pixels, it's wide enough to display web sites without weird reformatting. The 1GHz snapdragon ARM-based CPU is very fast, and the browsing experience is fantastic (and it does have multi-touch pinching zoom). The Android 2.1 UI has all the buttons and functions in the right places. This is very much unlike Android 1.5 on my Samsung Galaxy 7500, which was incredibly clunky, slow and unresponsive.

As Wired magazine says, there are 3 types of "flashes" that the Nexus one supports and the iPhone doesn't: Adobe Flash (to view YouTube videos and browse the web), an LED flash for the camera (5MP with autofocus), and a microSD slot for a flash card. My Nexus One came with a 4GB microSD, which I replaced by an 8GB.

It has been said that the Nexus One sales have been slow, but it's because the US cell market is so fragmented: T-Mobile uses GSM for 2G and standard frequencies for 3G, but their coverage sucks; Verizon has good coverage and uses normal 3G frequencies, but they use CDMA for 2G instead of GSM like everyone else; AT&T uses GSM and has good coverage, but they use weird frequency bands for 3G. Bwaaaaah!

Why couldn't the US government do its job and establish standards, as Europe did?

In any case, the Nexus One now works with a carrier that actually has decent coverage. The apps are fabulous (even has a VNC client), but I haven't been able to figure out how to use the 3G connection from a laptop through BlueTooth.

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JeeLink: Arduino + RF 
Monday, March 29, 2010, 12:20 AM - Electronics
The JeeLink v2 is an Arduino with an RF link package in a tiny form factor. It costs about 30 Euros. It can be paired with an 18 Euro JeeNode, also an Arduino + RF module.
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Aerotrain: the documentary 
Monday, March 8, 2010, 06:00 PM - Flying Contraptions
The Aerotrain was a French R&D project headed by engineer Jean Bertin in the 60's and 70's to build a high speed hovercraft monorail. The first prototypes of the Aerotrain used gas turbines for levitation and propulsion. Later models used a linear motor for propulsion and gas turbines for levitation. There are a few fan sites, that trace the history of the development

Interestingly, the technology was licensed to an American company in Colorado called Rohr Industries. They developed and tested a prototype, but the project was later abandonned.

A French documentary filmmaker tracked down the surviving prototype to a museum in Pueblo, CO. He made a documentary about it. This documentary is available on YouTube in six parts. An English version is also available. The movie is also downloadable.

The project received a lot of publicity in France in the late 60's and early 70's when I was growing up. A friend of my aunt's was a young engineer at Bertin in the early 70's, working on the Aerotrain. Growing up, I was totally fascinated.
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Personal Electric VTOL aircraft from NASA 
Thursday, January 21, 2010, 12:35 AM - Flying Contraptions
NASA is studying a single "seat" battery-powered VTOL personal aircraft called the Puffin. The on-line edition of Scientific American has an article on the Puffin.

The Puffin has two contra-rotating propellers in the front, and four tail booms with tail planes that fold out to turn into a landing gear for vertical landings. The pilot "stands" in the plane (when sitting on its tail), and lie on his belly when the plane flies horizontally.

The 4.1m-wingspan plane is powered by a 45kg lithium-phosphate battery that gives it a range of just 80km at a cruising speed of 240km/h, but progress in battery technology could triple the range over the next 7 years. The motors have an approximate total power of 45kW.

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Operation: No Smoking May 16th, 2010 Plerguer, France 
Monday, January 18, 2010, 11:55 AM - Flying Contraptions
The Aero-Modèle Club de la Côte d'émeraude (AMCCE) in Plerguer, near beautiful Saint-Malo, France, is organizing an all-electric fly-in on May 16th 2010. They call the event Operation No Smoking. The website shows pictures of several electric planes from yours truly (I spend some of my summer vacation nearby and fly there on week-ends).

Here is a satellite pic of the flying site:

View Larger Map
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Parrot AR.Drone: super-duper wifi-enabled, Linux-based quadricopter with vision 
Thursday, January 7, 2010, 02:55 AM - Flying Contraptions
The Parrot AR.Drone is a very exciting and very unusual quadricopter: it is Wifi enabled and has two on-board cameras. At first glance, you could think of it as a flying version of the Rovio. Essentially it is a self-stabilized flying wireless webcam. But the AR.Drone has much more to offer to TechnoToy enthusiasts: it comes with a "shared source" API that allows any wifi-enabled device to get video and sensor data from it and to control it. The website has a number of drool-inducing videos of iPhone controlled AR.Drones, and augmented reality games in which AR.Drones appear to fight giant robots or appear to shoot lasers at each other.

More videos are available on YouTube.

The specifications are nothing short of amazing, really a dream come true for anyone interested in tinkering with flying robots: 6 DoF IMU (3 accelerometers, 3 gyros), 468MHz ARM9 CPU running Linux (which should open the door to custom firmware hacks), an ultrasound altimeter/ground detector that allows automated takeoff and landing. Last but not least, there are two cameras: the first one looks down and is used for vision-based stabilization and ground target detection (176x144 resolution, 60fps, 63 degree field of view). The second camera (640x480 resolution, 15fps, 93 degree FoV) looks forward and its output can be streamed through wifi.

There is no price and no release date, but I'm guessing this is not going to be cheap.....

The coolest aspect of the whole thing is that it is hackable. There is a developer website with a Wiki and downloadable source code (registration required). The system is "open" but not open source in the traditional sense (the license of the API is not an open source license).

Even more interesting, the protocol to communicate with the AR.Drone from the ground (e.g. from an iPhone or a Linus box) is documented in the Developer Guide. Apparently, it consists in sending a bunch of "AT"-style command through a Unix socket. Nice.

Oh, and there is a facebook page

The puzzling thing is that Parrot is a French company which, until now, was involved in high-end cell phone audio accessories and expensive designer digital photo frames. What prompted this 400-employee company founded by a former journalist to get into the hobbyist/toy business?
Perhaps the fact that their CTO used to work at Arianespace?
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iPhone vs Droid, XKCD style. 
Friday, December 25, 2009, 11:22 AM - Misc TechnoToys

link to more XKCD.

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6 DoF IMU + Arduino 
Sunday, December 20, 2009, 04:02 PM - Electronics
The DIY Drones store has a very useful piece of hardware: the ArduIMU+ v2. It's an Arduino-compatible board with a 3-axis accelerometer chip and a 3-axis gyro chip with appropriate filters. It also has a connector for a GPS module (with a 4Hz refresh rate). All of this for $100 (plus $90 for the GPS). Very useful.
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Modifying an ESC for digital speed control 
Monday, November 30, 2009, 03:50 PM - Electronics
The tight control loop of quad-rotor helicopters requires very fast response from electronic speed controllers (ESC). Unfortunately, all hobby ESC are PWM controlled, and can't accept pulses at a high rate. This introduces lags in the control loops. Some folks have figured out how to hack commercial hobby ESCs so as to control them with an I2C digital interface. There is a whole thread about this on RC Groups, as well as a PDF file with detailed instructions, and schematics.

The alternative is to buy an I2C compatible ESC from YGE: 60 Euros (about $90) for the 18A YGE-18i, or 70 Euros ($115) for the 30A YGE-30i. Ouch!

Speaking of which, for you ESC DIYers, Fairchild has a 40V, 20A, Dual N & P channel mosfet pair, the FDD8424H (available at Mouser for $0.86).

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Micro heli and 3D-capable plane from e-Flite 
Monday, November 30, 2009, 01:18 PM - Flying Contraptions
e-Flite has come up with two interesting products: the Blade mSR ultra-micro helicopter, and the 4-Site ultra-micro 3D airplane.

The Blade mSR comes in an a "bind-and-fly" version for $150 (requires a separate Spektrum 2.4GHz DSM-compatible transmitter), and an RTF version for $180 (which includes a transmitter). The rotor diameter is 180 mm, and the mass is 28 grams. It uses a 120mAh single-cell LiPo battery.
It's available from Hobby Lobby, and from Red Rocket Hobby.

According to some reviews, the Blade mSR is the first single-rotor (non-coaxial) micro-heli that flies well. Most single-rotor micro helis have a separate motor for the tail rotor. These motors have relatively long reaction times, which makes the heli rather difficult to fly (they will rotate every time you increase or decrease the throttle). The Blade mSR is so tiny that the inertia of its tail rotor is very small, and the reaction time is very short.

The 4-Site Ultra-Micro comes in 2 version: "bind-and-fly" for $170, and "PNP" for $110. A Spektrum DSM-compatible transmitter is required. The wingspan is 386 mm, and the mass is 35.5 grams, with a single-cell 150mAh LiPo battery. e-Flite has other such small planes, but this is the first 3D capable ultra-micro from them. The plane includes a 5-in-1 P board with a 2.4GHz DSM receiver, a brushed speed controler, and two linear servos. Two additional servos for the ailerons are pre-mounted on the plane.
It's also available from Hobby Lobby, and from Red Rocket Hobby.

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Shrediquette: an Arduino-based Tri-copter 
Monday, November 30, 2009, 01:02 PM - Flying Contraptions
The Shrediquette is a tri-rotor helicopter built by William Thielike from Germany. William is a PhD student in biology, who seems to have many talents: micro-controller system design, control, mechanical design, flying contraption construction, as well as film making.

His tricopter is built around an Arduino Pro Mini micro-controller. Oddly, William didn't use the Arduino development tool and C/C++ programming language: he wrote his software in Bascom, a dialect of BASIC.

The yaw control is performed by rotating the tail boom with a servo. This very unlike the more conventional servo-less yaw control of quadcopters, but it's practically unavoidable for tricopters.

Much of the material is available for download, including the schematics, the PC board Eagle files, and the Bascom source code.

An awesome video (below) shows the capabilities of the tricopter.
More videos from William are available on Vimeo.

Tricopter - The Movie... from W. Thielicke on Vimeo.

Thanks to Bertrand for the link.

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eRC Micro P-51 Mustang RTF for $99 
Tuesday, November 3, 2009, 12:05 AM - Flying Contraptions
Hobby Lobby has the eRC Micro P-51 Mustang for $99.00. The diminutive ready-to-fly warbird has a 37 cm wingspan, weighs 30 grams, and comes with a 4-channel 2.4GHz radio. The plane has proportional control for the ailerons, elevator, and throttle. It uses a geared brushed motor.

Apparently, there is no rudder control as with the similarly sized Kyosho Minium Piper Cherokee. But the Minium is $180....

They will be rolling out a spitfire in December.
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David Berkman at Smoke 
Sunday, November 1, 2009, 02:43 PM - Jazz
My favorite jazz composer/pianist on the New-York scene David Berkman was playing at the uptown club Smoke yesterday and Friday with Antonio Hart on the sax, Ted Poor on drums, and Ed Howard on bass. I went to the last set on Saturday and it was awesome. David has a new CD out entitled Live at Smoke (also on Amazon MP3 downloads), with live performances of some of his fantastic pieces from earlier records, like Weird Knack, which appeared on his amazing 2000 CD Communication Theory (though it was mispelled "Weird Knock" on that CD). Interestingly, David post the scores of many of his compositions on his website (though the links seem dead right now).

In fact, I first heard of David Berkman while listening to the WBGO radio station back in 2000. They played a piece from Communication Theory. I was hooked.

David played on Joel Frahm's first two CDs ("Sorry, No Decaf", and "The Navigator"), and composed some of the pieces on these CD (like "Interesting perhaps, but hardly a fascinating rythm"). It would be awesome if David and Joel could record together again. It would also be awesome if David played more often in NYC, particularly downtown.
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ttymidi: serial/usb to MIDI for linux 
Saturday, October 17, 2009, 10:26 PM - Electronics
TTYMIDI is a linux hack to allow any serial or serial/USB device (such as the Arduino) to produce MIDI events compatibel with ALSA in Linux. This makes it easy to turn any Arduino-based hack into a MIDI controller.

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