Monthly Archives: May 2016

What is Micro-porous Copper Foam Technology?

Apart from Aluminum, Copper is the most widely used material for making heat sinks, because properties of copper make it suitable for the purpose. Chief among them is its superior thermal conductivity and malleability. That means copper conducts heat better than most other materials and it is easy to form into different shapes that a heat sink necessitates. However, latest research has revealed another form of copper that promises still better thermal conductivities.

In today’s high-density electronics, thermal management plays a significant role. Reducing heat generation and removing heat from tight spaces is a constant challenge for electronics engineers designing smartphones, laptops, tablets and other space-constrained gadgets.

Engineers manage the heat generated in such high-density electronic designs by deploying optimized heat sinks. Versarien, a materials specialist, has found that using a micro-porous structure of copper maximizes its surface area enabling the heat sink become more effective in dissipating heat.

Micro-porous copper or copper foam has pores that vary in size from 300 to 600µm. The pores also make it lighter than solid copper, with a relative density of around 37%. Most importantly, the pores increase the surface area much more than that in traditional copper foam. A lost carbonate sintering process is responsible for generating the micro-pores.

Metallurgists compact and sinter a mixture of pure copper powder with a carbonate powder. This makes a matrix of copper ligaments, with the carbonate powder sandwiched in between. Once the mixture cools, water dissolves the carbonate, which is then recovered for recycling. The remaining copper forms a regular and uniform structure, which is highly rigid, porous and permeable and whose density per unit volume the manufacturer can easily control.

At present, Versarien makes heat sinks in form factors ranging from 10x10x2 to 40x40x5 mm. The company anticipates micro-porous copper foam heat sink usage in VOIP equipment, broadband routers, cable modems, flat panel displays, set top boxes and Gigabyte Passive Optical Network communication infrastructure.

Micro-porous copper foam is like an open cell structure, with an extraordinarily large number of interconnected pores distributed uniformly throughout the base copper material. To enhance its radiant properties, the manufacturer deposits a thin but exceedingly hard copper oxide coating at a high temperature. That gives the copper its high emissivity so desirable in a heat sink. Overall, you can have a significant height reduction in a passive heat sink footprint, without any compromise on its capacity to remove heat.

Testing provides evidence of its superior efficiency in heat removal. Micro-porous copper foam heat sinks outperform traditional solutions by more than 6°C/W. That means for every Watt of heat removed by a micro-porous copper foam heat sink, there is an additional temperature drop of about 6°C above what is offered by traditional heat sinks. For example, the thermal resistance of a 40x40x5 mm micro-porous copper foam heat sink is 17.4°C/W for an applied load of 5W. For a 20x20x5 mm heat sink, the thermal resistance is 35.8°C/W for an applied load of 2W.

Conventional heat sinks require special appendages such as pins, fins or micro-channels to increase their surface area. That increases the space taken up by the heat sink and makes it less efficient. When available space is limited, it is more practicable to use micro-porous copper foam heat sinks.

Solar Powered Drone Beams Internet

Certain regions of the Earth are presently out of the ambit of the Internet. Nearly 10% of the population or more than 4 billion people live so far from fiber optic cables or cell towers that they are unable to reach the Internet. Facebook is set to end this isolation by having a drone fly overhead while beaming Internet down to such areas.

At their Connectivity Lab, which is a division of Facebook’s Internet.org, researchers confirm the completion of such a drone. This is the first step Facebook is taking before it builds a larger fleet. They have not yet flown the craft, but Facebook has already been testing their concept over the UK with versions one-tenth the size. They intend to conduct flight tests of the full-size drone before the end of this year.

Facebook will be using the solar-powered V-shaped carbon fiber craft, named Aquila or Eagle (in Latin), for beaming down wireless Internet connectivity to expand Internet access. About a year ago, Facebook launched Internet.org. Although their intentions were to provide Internet access to those in the world who do not have a reliable connection, the project has received a lot of dissension for not adhering to net neutrality – especially in India.

Facebook has designed and built Aquila in 14 months. The drone will fly in the air for 90 days without touchdown. To launch it up into the air initially, technicians will be attaching Helium balloons to the plane.

With a wingspan of 46 yards or 42 meters, Aquila has to move constantly to stay aloft. Therefore, it will circle a three-km or two-mile radius. During the day, when the craft can generate energy from the sun, it will float up to 90-thousand feet or 30 Km. However, the craft drifts down to 60-thousand feet or 20 Km at night for conserving energy. While not planning to sell the drones at present, Facebook intends to use them for expanding Internet access.

The research team has been able to increase the data capacity of the lasers involved in the project. This is one of the biggest breakthroughs as the new system can communicate at speeds of 10 GB per second using a ground-based laser to talk to the dome on the underbelly of the plane. This is about 10 times faster than the current capabilities allow.

Facebook is not alone in their endeavors to bring wireless Internet to rural regions. Rivals Google also have a program up their sleeve – Project Loon. They plan to put up high-altitude Helium balloons with transmitters attached. Although Google has not launched their project yet, they claim it is in a more advanced stage compared to where Aquila is at present.

Therefore, very soon, you may see a huge 900 lb. drone nearly the size of a Boeing 737, slowly circling 11 miles up in the sky. Currently, Facebook’s mission is mired in controversy. All over the world, critics are questioning several practices of Facebook’s Internet.org on security, fairness and privacy grounds. There is a danger countries may spy on and repress their citizens. In addition, first-time users of the Internet might be limited to what Facebook provides them as news and information.

Incubating Eggs with a Raspberry Pi

Incubating eggs is a process best left to the mother bird alone or sometimes the father bird. That is because nature has programmed them for applying the appropriate temperature profile necessary to hatch their eggs successfully. However, this vital information is no longer the sole proprietary knowledge of the birds alone. Humans, at least those who rear chicken, probably know as much.

Hens incubate their eggs by sitting on them and instinctively controlling several factors, mainly the temperature and humidity, with their body heat. They also turn the eggs over periodically, which is vital for a successful hatch.

Although there are commercial alternatives available, building your own incubator has its own advantages such as affordability and the ability to add features. Dennis Hejselbak from Denmark has not only made such an incubator, but has also posted complete build instructions here. For those who want to follow, Dennis uses a Raspberry Pi or RBPi, the tiny, versatile single board computer for controlling his incubator. He has made available the necessary Python codes and the wiring schematics as well.

Dennis has built his incubator box from polystyrene, which makes it well insulated. He controls the temperature inside using an incandescent light bulb and an old CPU fan. Wet sponges inside the incubator supply it with the moisture necessary, while a hygrometer keeps an eye on the humidity levels. The RBPi controls the light bulb and the CPU fan based on feedback from a temperature sensor and the hygrometer. Dennis keeps watch on his eggs via a camera attached to the RBPi. He has enabled his RBPi with Wi-Fi and real time pictures of the incubation process are available on his website.

The only process Dennis has not attempted to automate so far is the periodic turning over of the eggs. He does this manually, about three times each day, until the eggs hatch. Although hatching eggs takes about 21 days on average, some eggs may hatch a day or two early and some a day or two late.

As Dennis is using forced air for his incubator, he programs the RBPi to keep the temperature within about 99-99.5°F (37.2-37.5°C). For successful hatching, eggs require 45-50% humidity from day 1 to 18 and 65% for the balance few days. Dennis has placed the temperature and humidity sensors to hang just above the eggs.

As the incubator is a large box, placing the RBPi on its top was not a difficult task for Dennis. This has its advantages as the box needs only a single hole for both the cables of temperature and humidity sensors to pass through – making it easier to insulate. Of course, other holes are necessary for the cable of the light bulb. Dennis handles all monitoring of the RBPi from outside, without having to open the incubator.

The RBPi controls the temperature by turning the light bulb on or off as necessary. A simple electromagnetic relay operated with a power transistor is enough for this purpose, although those who are adventurous among you may opt for a more expensive solid-state relay.

Butterfly Technology Boosts Solar Panel Output

We normally do not relate butterflies to solar panels. After all, bees and butterflies are good for pollinating flowers and transforming them to fruits so that nature can propagate. On the other hand, solar panels are human creations that collect energy from the sun for the use of humankind. The link between the two seems rather distant, apart from the fact that the sun is the basic force that drives all life on our planet. However, science finds the humble butterfly could be holding the key to unlock new techniques for making solar energy cheaper and more efficient.

Cabbage White butterflies need to heat up their flight muscles before they can take off. Researchers at the University of Exeter have observed that the butterflies adopt a specific posture to maximize solar heat capture. The butterflies position their wings in a V-shape, which, when the researchers adapted for their solar panels, increased the power-to-weight ratio of the panels by about 17 times, making them more efficient.

Scientific Reports, a leading scientific journal has published the research. The research team contained members from both the Centre for Ecology and Conservation and the Environment and Sustainability Institute, based at the University of Exeter in the Penryn Campus in Cornwall. According to Tapas Mallick, the lead author of the research, although bio mimicry is popular in engineering, such unparalleled multidisciplinary research is opening pathways for developing low cost solar panels.

Butterflies usually depend on the sun to heat up their flight muscles before they can take off. However, researchers found the Cabbage White butterflies taking flight before other butterflies did, even on cloudy days. The energy from the sun is limited on cloudy days, forcing insects to make maximum use of the available energy to heat up their flight muscles.

Researchers observed that Cabbage White butterflies adopted a v-shaped posture, known as reflectance basking. That allows the butterflies to maximize the concentration of solar energy onto their thorax, so necessary for fast heating up the flight muscles. The wings of the butterflies have a specific sub-structure that allows maximum light from the sun to be most efficiently reflected onto their muscles, which warm up to the optimal temperature as quickly as possible.

The scientists then investigated the process of replication of the butterfly wings for developing a new, lightweight reflective material solar energy products could use. They found that by replicating the simple monolayer of scale cells on the butterfly wings, they could optimize the power-to weight ration of solar concentrators. That made the solar cells lighter and more efficient.

The team also found the optimal angle at which the butterfly held its wings. When the butterflies tilted their wings by about 17 degrees to the body, they were able to increase the temperature of their bodies by 7.3°C more than when they held their wings flat. By positioning the reflectors at 17 degrees within the solar cells, researchers found the output from the solar cells increased by 50 times.

Therefore, by studying the manner in which the lowly butterfly maximized its use of solar energy, scientists could not only double the output of their solar cells. They were also able to improve its power-to-weight ratio significantly.

A Primary Display HAT for the Raspberry Pi

A portable single board computer such as the Raspberry Pi or the RBPi ought to have a portable screen, preferably a touch screen that is comfortable to use. This is a long overdue, much sought-after request from users, especially from developers, who see and use several smartphones and tablets with capacitive and or resistive touch screens.

The Pi Foundation has been hard at work on developing a seven-inch touch screen as an add-on to the RBPi. This would be appropriate for a number of projects where you would want to pit the RBPi against a portable tablet or even a laptop. However, for development of embedded systems, people prefer a smaller and more compact version of display. The 2.4-inch TouchScreen display from 4D Systems fills this void perfectly and affordably, being compatible with the RBPi models A+, B+ and RBPi2.

The TouchScreen is almost as large as the RBPi board and covers it as far as the USB and Internet ports, while sitting perfectly on the bank of GPIO pins and covering all of them. At present, the other end of the TouchScreen hangs as there is no support and there is a possibility of its backside touching the connectors. You can expect a set of stand-offs to come soon and these will secure the screen above the connectors and pins of the RBPi.

According to an intentional design decision between 4D Systems and element14, the TouchScreen fits very neatly within the official case of the RBPi. That leaves out only the portable power, which, if the official case could support, would have made the RBPi truly portable.

The 30 gm. TouchScreen module dimensions measure 56.5×65.0x14.2 mm. It has a viewing area of 49.0×36.7 mm, with four mounting holes of 2.6 mm diameter. The QVGA TFT screen has a resolution of 240×320 pixels and sports 65K true to life colors. Integrated with the screen is a 4-wire resistive touch panel. You can display the full GUI output or the primary output on the TouchScreen, just as would a monitor connected to the RBPi. The display uses a PWM control for the backlight and on board, there are three backlight choices, selectable with jumpers – On, Off and PWM.

The display module connects to the RBPi via a high-speed SPI interface working at 46MHz and using SPI compression technology. If you have a kernel that compresses images, expect higher frame rates than the typical value of 17 frames per second. The module does not require a separate power supply as it powers itself directly from the RBPi.

Although the screen has full capabilities, its limitations are because of the way Linux handles framebuffers. For example, although the display can play full motion video, you cannot render OpenGL to the screen. That means you cannot expect hardware acceleration from the SPI screen. Someday, this may be possible if someone tweaks the Broadcom code for the VideoCore and OpenGL.

What is 3D Flash Memory?

Slowly, but steadily, the memory market is veering away from magnetic disc storage systems to solid-state drives or SSDs. Not only are prices falling fast, manufacturers are producing SSDs with improved technologies, leading to denser memories, higher reliability and lower costs. For example, Samsung has recently announced SSD and systems designs that will drive their new 3-D NAND into mass markets.

Samsung’s latest SSDs are the 850 EVO series. According to Jim Eliot, a marketing executive for Samsung, these are 48-layer, 256 Gbit 3-D NAND cells, with 3-bits per cell. The new chips show more than 50% better power efficiency and twice the performance when compared to the 32-layer chips Samsung is now producing. In the future, Samsung is targeting Tbit-class chips made with more than 100 layers.

On a similar note, an engineer with SK Hynix says that by the third quarter, the company will start production of 3-D NAND chips with more than 30 layers. By 2019, SK Hynix will be making chips containing more than 190 layers.

At present, 3-D NAND production is still low in yield and the cost of production is higher than for producing traditional planar flash chips. However, these dense chips bring promises of several generations of continuing decreases in costs and improvements in the performance of flash. According to analysts and vendors, it might take another year or so before the new technology is ready for use in the mainstream.

Samsung was the first to announce 3-D NAND production, with rivals catching up fast. Toshiba has already announced its intentions of producing 256 Gbit 3-D NAND chips in September. These will also have 48 layers and 3-bits per cell.

According to Jim Handy, an analyst at the Objective Analysis, Los Gatos, California, sales of the 3-D NAND will not pick up before 2017. With Samsung shipping its V-NAND SSDs at a loss, they are gearing up to put the 48-layer devices in volume production. This will enable them to beat the cost of traditional flash.

The reason is not hard to find. Wafers of 3-D chips with 32-layers cost 70% higher than wafers for traditional flash. On the other hand, wafers for 48-layer versions cost only 5-10% higher, but have 50% more layers. Therefore, although the 48-layer chips tend to start with a 50% yield, they will easily approach the planar flash yield levels with a year or so.

According to expert analysts, it takes a couple of years for any new technology to mature. Therefore, the prediction that 3D NAND will reach a majority of flash bit sales only after 2018.

The number of 3D layers providing an optimal product is still under experimentation. Also, included is the development of a new class of controllers and firmware for managing the larger block sizes. Vendors are still exploring other unique characteristics of these 3D chips.

For example, Samsung has designed controllers and firmware that addresses the unique requirements of 3-D NAND and is selling its chips only in SSD form. According to the head of Samsung’s Memory Solutions Lab, Bob Brennan, SSDs provide higher profit margins as compared to merchant chips, and are the fastest way to market.

UPS-PIco for Uninterruptible Power for the Raspberry Pi

The innovative Raspberry Pi or RBPi, the tiny single board computer, has endeared itself to the young and old alike. When used for critical applications, it is often necessary to supply the RBPi with continuous power, for which, an advanced uninterruptible power supply such as the UPS PIco offers several innovative power back up and development features.

With a 300mAh LiPO battery, the standard UPS PIco offers a safe shutdown during a power cut. However, you can easily upgrade this battery to an extended version of 3000 mAh. This will allow you to use the RBPi for a prolonged 8 hours, even if no power supply is available.

An embedded measurement system within the UPS PIco works continuously to check the powering voltage of the RBPi. As soon as it detects the absence or the inadequacy of the cable power of the RBPi, or senses a power failure, the UPS PIco switches over to its battery source automatically. The module continues to check the voltage on the RBPi cable, and if the power is once again available or adequate, it switches over from the battery and allows the regular cable supply to power the RBPi.

You do not need any additional cabling or a separate power supply for charging the battery, as the UPS PIco is a powered unit, with the GPIO pins on the RBPi powering and charging the battery pack intelligently.

The UPS PIco complies with the HAT standards for the RBPi models A+/B+ and 2B. Mechanically, it is compatible with the original models A & B of the RBPi, provided you use an extension header. Additionally, the UPS PIco is compatible with most cases housing the RBPI, especially as it fits within the footprint of the RBPi and does not require any additional powering.

An additional feature on the UPS PIco allows remote operation. An optional infrared receiver does the trick. The PCB routes the infrared receiver directly to the GPIO18. With this feature, you control the RBPi and UPS PIco remotely.

Finally, if you are likely to operate the RBPi in a very high temperature environment, you will need to cool it with external methods. The UPS PIco allows you to implement a PWM fan controller with an automatic temperature control feature. With a micro-fan fitted on the RBPi, the UPS PIco keeps your CPU cool.

Apart from being HAT compliant with RBPi models A+/B+ and 2B, the smart uninterruptible power supply or UPS is fully plug and play. Although the integrated LiPO battery provides 8-10 minutes of back-up power, an additional 3000 mAh battery pack extends this run-time to nearly 8 hours, providing a power backup of 5V, 2A with a peak output of 5V, 3A.

A real time clock simulated with software, with the battery backup offers a functionality offering a file-safe shutdown. The UPS PIco has a pair of user-defined buttons and a pair of user-defined LEDs, along with integrated buzzer for UPS and user applications. With I2C Pico and RS232 RBPi Interfaces, the user can easily monitor and control the operations of the UPS. Add-on boards are easy to use, as the UPS PIco has a stackable header.

Quadriplegics Can Control Exoskeletons with Their Brain

Artificial limbs help people who have lost a part of their arms or legs to regain partial functionality of their extremities. However, for those who have lost control of a major part of their bodies and thus rendered quadriplegic, artificial limbs are not of much use. For addressing such and other whole-body disabilities, exoskeletons are showing great promise.

Scientists working at the Technische Universitat Berlin and Korea University are creating such lower-limb exoskeletons. The control system here is completely hands-free. Rather, it is a brain-to-computer interface, which controls the exoskeleton, by decoding and making use of signals from the wearer’s brain. According to the researchers, volunteers who were given the exoskeleton to use took only a few minutes for learning to operate the system. Therefore, substantially paralyzed people may hope to walk again with the help of this exoskeleton.

Research on such exoskeleton systems is not new and several types are in development and in limited production in many parts of the world. However, most achieve controls by detecting subtle movements in the upper body of the wearer. However, the difference in the KU/TU Berlin unit is the control is entirely dependent on brain signals. Therefore, this is useable even by a completely paralyzed person.

The human brain generates different signals when the person stares at a specific LED. These signals are detected and interpreted to be used for controlling the hands-free exoskeleton. An EEG brain control interface connects wirelessly to the main computer of the control system.

In actual practice, the wearer stares at any one of five flashing LEDs. This initiates waves in the wearer’s brain and an electroencephalogram or EEG worn as a cap reads the signals. Because each LED flashes at a different rate, focusing on any one at a time produces a specific signal pattern in the brain of the user corresponding to a desired mode of movement. The computer system interprets the readings of these signals sent to it from the EEG cap and converts them to system instructions for operating the exoskeleton.

As this method of control does not require detection of movement from any other body part, it is eminently suitable for even those who have lost the capacity for voluntary body control, except for eye movements. Ordinarily, such people would not be able to use or control a standard exoskeleton. According to the researchers, their system has a much better signal-to noise ratio.

The brain generates signals depending on external signals it receives from its surroundings. This acts like noise to the actual control signal desired for movement. By concentrating on a flashing LED, the researchers are effectively separating the user’s brain control signals from being cluttered with external stimuli. The result is a more accurate exoskeleton operation than what a conventional hard-wired system could have achieved.

Exoskeleton systems are notorious for creating loss of electrical noise, especially affecting the EEG signals. However, the frequency of the flickering LED acts as a filter to separate the EEG signal effectively. This exoskeleton system helps people with high spinal cord injuries or those with motor neuron disease who face difficulties in communicating or using their limbs.

Liquid Droplets That Levitate On a Blue Light Pad

Scientists in France have found a novel technique to levitate liquid droplets on a cushion or pad of blue light. The effect sets off a striking light show with the droplets generating sparks as they drift over the blue gap.

The effect is quite like the Leidenfrost Levitation in which a liquid drop is made to levitate on its vapor layer created over a hot surface. However, while in the Leidenfrost effect, the temperature is the initiating factor, here it is electricity creating the interesting spectacle.

Plasma creation

The researchers discovered that a high pulse of electricity applied to a gas could vaporize it so the gas glows with a bluish light. This remarkable find may present an economical technique to produce movable micro plasma layers. Furthermore, the study yields remarkable insights into basic principles of physics.

Physicist Cedric Poulain of French Alternative Energies and Atomic Energy Commission explains that the technique is a simple and an innovative way to create plasma.

In the experiment tried out by the research workers, over 50 volts of electric power was applied across a droplet of dilute hydrochloric acid suspended above a metallic plate. This made the droplet levitate over a region radiating a light blue glow.

Cushion of vapor

At voltages above 50V, the base of the acid droplet started to produce sparks. The drop rose, increasing the gap above the metal plate and a blue light filled up the gap. The scientists first assumed that the droplet was lying on a cushion of gaseous hydrogen produced by the electrolysis of the acidified water. Further scientific analysis established that the gas cushion primarily consisted of water vapor.

Poulain explained that extremely small space between the metal plate and the droplet makes it easy to set up the high electric field needed to produce the plasma layer, even with moderate electric voltages.

Contrasting boiling with electrolysis of water

The team compared the electrolytic dissociation of water with boiling. Poulain brought forward the example of a water drop placed on the surface of a heated vessel. He pointed out that at temperatures higher than 100 degrees Centigrade, the drop spreads out and bubbles form on the surface. At temperatures exceeding 280 degrees Centigrade, a vapor cushion can be seen forming in between the drop and the vessel surface. This makes the water drop levitate so that there is no contact between the drop and the vessel surface.

The team described the transition in electrolysis as somewhat similar.

Figuring out the blue light phenomenon

According to the team of researchers working on the project, the emission of blue light was the most striking feature of the study. For a proper conception of the phenomenon, the scientists plan to explore the makeup of the plasma layer. They believe that two types of plasma are superposed, though they cannot yet understand the effect.

The scientists also intend to scrutinize the liquid dynamics at the lower surface of the droplet when the sparks just start to fly out. This should give further information regarding the nature of the plasma layer.

Leap Motion with the Raspberry Pi

Robots have the capability to work where humans would find it inconvenient. In fact, that is one of the reasons people build robots. For example, in areas where high amounts of nuclear radiation would be fatal for a human being, a robot can work happily. Science fiction movies have exploited this feature several times – a robot mimicking the hand movements of its human controller, when watched and manipulated from a safe distance. Now, with a few motion-controlled servos, Leap Motion and Raspberry Pi or RBPi, the tiny Single Board Computer, you too can make a robot with the ability to mirror the movement of your hands. Additionally, you can do this even when you are sitting on the opposite side of the Earth.

The project involves two servos, each mirroring the movement of your individual hands. A Leap Motion controller captures the motion of your arms and sends appropriate instructions to the RBPi, which drives the two servos using a PWM driver. Two 8×8 RGB LED matrices individually attached to the servos react to each finger movement on your hands. The Leap Motion controller communicates with the RBPi via PubNub Data Streams.

The project uses the RBPi Model B+, Leap Motion controller with Leap Motion Java SDK, four numbers of Tower Pro Micro Servo, the Adafruit PWM Servo Driver and an optional display case.

The Leap Motion controller is a powerful device. It is equipped with three infrared LEDs and two monochromatic IR cameras. The cameras capture the movement of your hands and Leap Motion publishes their attributes to a channel via PubNub. The Leap Motion SDK has the attributes pitch, yaw and roll pre-built in it and actually separates the movements of your hands into the three attributes.

For achieving real-time mirroring, Leap Motion sends the attribute information messages nearly twenty times in a second. It sends information about your individual arms and each of your fingers to PubNub. Since the RBPi subscribes to the same channel, it is able to parse these messages for controlling the servos and the RGB LEDs.

To start, you will need to open a Java IDE and create a new project. You will find a guide for the Leap Motion Java SDK here. Follow up this step with installing the PubNub Java SDK. Make your project implement Runnable, which will allow all the Leap activity to operate in its own thread.

Every second, Leap Motion captures nearly 300 frames. Each frame has a huge amount of information about the hands, such as the number of fingers presently extended and hand gestures such as pitch and yaw. To simulate the motion of the hands, one servo mirrors the pitch while the other mirrors the yaw. Incidentally, pitch is the rotation around the X-axis and yaw is the rotation around the Y-axis. Both servos rotate 180-degrees with a sweeping motion. The resulting servo mimics most of the movements your hands make.

Leap Motion outputs values for the pitch and yaw in radians. The RBPi is responsible for converting these radians into degrees and finally into PWM or pulse width modulation between 150 and 600 MHz for driving the servos.Leap Motion with the Raspberry Pi