Hackaday Links: Sunday, May 12th, 2013

May 12, 2013 by Mike Szczys 23 Comments

[Johnathan Crawford] isn’t bashful about tearing the insides of his truck apart. He’s built his own remote starter using a Raspberry Pi.

We vaguely remember hearing about a startup that planned to deliver tacos using quadcopters instead of people. We assume that company was a bust but here’s the concept in action at the 2013 RoboGames [thanks Don].

On the topic of food: pizza and joysticks… do they go together? Perhaps. Here’s a joystick made out of an empty pizza box (note the remains of grease stains inside).

[Jonathan] brings to our attention the problem of running out of fingers to press all the buttons on your Monome at just the right moment. No worries, just add some solenoids to act as extra fingers.

Apparently some Samsung cameras (NX20, NX210 and NX1000) can use their USB port as a shutter release. The trick is finding the right resistor values for the ID pin [thanks Janne].

Plagued with a tablet dock that wasn’t weighty enough to prevent the device from tipping over [John] filled base with lead to keep the thing upright.

[Helmut’s] bathroom had no windows. He faked one using an Arduino and an RGB led.

And finally, as a reward for all the readers that made it to the bottom of the article, here’s a gem of a project. [Charlie] was inspired by the recent logic combo lock post to send in his own plans for a lock he made years ago. Unfortunately he can’t find the pictures from the build but the theory behind it is quite engaging.

An Arduino Hydrogen Blimp… Oh The Humanity!

January 19, 2013 by Mike Szczys 48 Comments

arduino-hydrogen-balloon

This sort of flying contraption seems more suited for indoor use. Well, except for the fire hazard presented by building an Android controlled hydrogen blimp. The problems we often see with quadcopters come into play when a motor wire comes loose and the thing goes flying off in a random direction. Loosing a motor on this airship will be no big deal by comparison.

Because the build relies on the buoyancy of the gas, light-weight components are the name of the game. The frame of the chassis is built from balsa wood. It supports two tiny DC motors which are almost indistinguishable in the image above. An Arduino nano and wireless receiver monitor commands from the transmitter and drive the propellers accordingly.

You may have noticed that we categorized this one as a chemistry hack. That’s because [Btimar] generated the hydrogen himself. He used an Erlenmeyer flask with a spout for the chemical reaction. After placing several heat sinks and other scraps of solid aluminum in the flask he poured on the lye solution. This generates the H2 but you need to keep things cool using ice to keep the reaction from getting out of control. We’re going to stick with helium filled blimps for the time being!

See this beast flying around [Btimar’s] living room in the clip after the break.

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Turning Four Smaller Helicopters Into One Larger Quadcopter

December 3, 2012 by Brian Benchoff 8 Comments

copter

There’s a reason we’ve seen a menagerie of quadcopters over the past few years – the key piece of any quadcopter build is an inertial measurement unit. Historically a very complicated and expensive piece of kit, these IMUs came down in price a few years back, allowing anyone with a few dollars in their pocket and a handful of brushless motors to build a four-bladed drone in their workshop.

[Starlino] built a few quadcopters, but he wanted to shy away from IMUs and get most of the mass of his new ‘copter over the center of the chassis. He came up with a design he calls the quadhybrid that can be built out of a quartet of those cheap 3-channel helicopter toys.

Most of the lift for [Starlino]’s quadhybrid comes from a pair of coaxial rotors from a Syma 001 3-channel helicopter toy. Anyone who has played with one of these toy helicopters knows how stable they are; if the tail rotor breaks, you’re left with a helicopter that can only go up and down.

To give his quadhybrid a few degrees of freedom, he attached four tail rotors from 3-channel helis to a few booms laid out in a cross pattern. By taking the receiver out of a 4-channel helicopter and adding his own controller board, [Starlino] made each of the tail rotors control the pitch and roll of the craft.

In the video after the break, you can see the quadhybrid is amazingly stable even without an IMU and surprisingly agile. As [Starlino]’s ‘copter can be made out of replacement parts for cheap 3-channel helis, we’ll expect a rush on these tail motors at your favorite online RC retailer very shortly.

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Building A Tilt Rotor UAV

October 4, 2012 by Mike Szczys 17 Comments

We see a lot of quadcopters, and even the occasional octocopter around here. But this build does it with just two propellers. It’s a tiltrotor build which allows the two upward-pointing propellers to tilt forward and backward. The real world equivalent of this UAV design that pops to mind is the V-22 Osprey.

The motors are mounted on a beam running perpendicular to the direction of travel. Each of them is mounted on a bearing which can be rotated by a servo motor. They rotate independently of each other, which allows for yaw. Of course roll is controlled by driving the propellers at different speeds and pitch is adjusted by tilting both mounts at the same time.

[Stephen] mentions that the tiltrotor design has several advantages over its relatives that use more than two props. This design costs less to build, uses less electricity, and makes for an easier autopilot implementation. If you want to see it in the air, don’t miss the clip after the break.

This is just the second tiltrotor build we remember seeing. The other one was a Halloween prop.

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Tutorial Explains The Concepts Behind An IMU

September 25, 2012 by Mike Szczys 12 Comments

[Anilm3] wrote in to share the IMU tutorial series he is working on. An Inertial Measurement Unit is most often found in self-balancing robots and quadcopters, providing enough high-speed sensor data to keep up with the effects of gravity. He previously used some all-in-one IMU devices in school which did most of the work for him. But he wanted to grind down and look at what each sensor spits out and how those measurements are used. The first installment deals with the accelerometer, using its data to calculate pitch and roll. For these demonstrations [Anilm3] is using this ADXL345 sensor board, an Arduino, and some processing sketches for testing.

Whenever working with sensors you need to take noise into consideration. The post shows how to implement a low-pass filter in the code which will help smooth out the readings. The filtered data is then fed to a couple of mostly-painless formulas which calculate the movement of the accelerometer in degrees. The demonstration sketch is mapped to a 3D cube to give you an idea of how accurate the accelerometer is. There’s a little bit of lag which would let a self-balancing robot have a nasty fall. The solution to this issue will be discussed in upcoming parts of the series. The next installment tackles the gyroscope sensor.

Remote Control Does Everything

September 10, 2012 by Brian Benchoff 31 Comments

After a year of development, the OSRC is ready to hit a manufacturing plant. This transmitter (and receiver) for remote control cars, airplanes, quadcopters, and semi-autonomous drones features modular everything and allows you to transmit video from the cockpit and display it on a screen in the palm of your hands.

This isn’t the first time we’ve posted something on the OSRC, but since then [Demetris], the team lead has released a ton of information on the capabilities of the OSRC main unit, the clip-on FPV display, and the receiver and transmitter modules made to operate with the OSRC.

Unfortunately, [Demetris] spent a good deal of money developing the OSRC and is now doing a pseudo-kickstarter, ostensibly to gauge interest and allay a bank’s fears when applying for a small business loan. If all goes as planned, the OSRC base unit should cost somewhere around €300, a significant sum, but really not that bad considering the OSRC simply does more than other high-end RC transmitters.

We’re hoping enough people will step up and promise to buy the OSRC after it goes into manufacturing, otherwise we’ll be waiting a few more years before the big names in the RC transmitter game manage to come out with a similar product.

Open Source Brushless Motor Controller

September 4, 2012 by Brian Benchoff 29 Comments

It’s been a long time coming, but efforts to create Open Source brushless motor controller are finally paying off.

The Open-BLDC project aims to create an open source motor controller for the brushless motors usually found in remote control airplanes, helicopters, and quadcopters. Normally, these motor controllers – usually called electronic speed controllers – can’t supply more than a few dozen amps, and are usually only controllable via a servo signal.

The Open-BLDC goes far beyond the capabilities of off-the-shelf ESCs with up to 200 amps of output, TTL level serial input, and the ability to use regenerative breaking.

While the Open-BLDC project is far from complete, the team working on the hardware hopes to add I2C, CAN, and PPM interfaces, along with speed and torque control.

There is no word on when, or even if, the Open-BLDC will ever be available for sale, but with the features it has it would be welcomed by just about any builder constructing a gigantic RC vehicle.