Author Archives: Andi

An Action Camera for the Raspberry Pi

If you are the type that goes biking into the mountains and all the while recording your adventures on camera while on the trip, you need a camera that is biking-centric, robust and suitable for long-distance trips. Of course, several suitable cameras already exist such as the GoPro, Fly6 and the Sony Action CAM, but they are expensive not accessible to all. On the other hand, an action camera for the Raspberry Pi (RBPi) is not only cheap, it is also open-source and suitable for the purpose.

The design of the RBPi action camera is based on off-the-shelf components. It is very easy to build this project if you have access to a soldering iron and a 3D printer. Of all the models of the RBPi series, model A+ consumes the lowest amount of power, which is an important factor to consider since you will be running it on batteries.

If you are trying out the camera for the first time with an RBPi, using an open-source case is advised.

For an RBPi camera meant to be used for biking, three design goals must be met: the project must have a long battery life, be capable of wireless communication and its enclosure must be simple and made of durable material.

Apart from using the RBPi model A+, meeting the first requirement means using a large battery, especially if your rides are going to be multi-hour long. For the second requirement, it is necessary to have both Wi-Fi and Bluetooth, to make it easy to communicate with the camera. The last goal contributes to the first two, therefore, it must be given due consideration. Since the action camera is meant for outdoor use, making every port available outside the case would have reduced the structural integrity and its dust/water resistance.

To package everything into a small enclosure and ensure their working, you may need to work on the Wi-Fi dongle first, as that sticks out more than anything else does. For this, you may need to remove the USB jack and then remove the adapter from its plastic case. You can solder the wires directly to the board. The Bluetooth module may be placed on top of the RBPi and a ribbon cable used to connect it to the headers underneath. Next, make a support for the battery and its charger/booster so they fit snugly under the RBPi. You may need a few spacers to ensure the protruding headers do not puncture the battery.

Place the camera as close to the side of the RBPi and design the case to around all the components along with the RBPi. Usually, the case will be in two parts, with the camera module mounted on the top. Keep the camera module within the case and mount it in place with screws.

Use two buttons, with which the RBPi will start and stop the recording sessions. This may require you to use special scripts (you can use those by Alex Eames) for the RBPi to listen to a button press to start the camera and another button press to stop recording. Communication with the RBPi is done primarily through ssh.

Hear Only What You Wish To: Doppler ear buds

When there is a need for solitude, peace and quiet, some resort to earmuffs. Although good for cutting off or reducing the loudest of noises in your neighborhood, earmuffs cannot help you to hear the sounds of the world to your liking – either you hear nothing or you hear it all – there is no in-between.

Now Doppler Labs has an ear bud that allows you to choose how you would like to hear the sounds surrounding you – with a volume knob. The ear buds are no hearing aids and neither are they a pair of headphones. Once paired to the iPhone, you have a way to customize your hearing. You turn a volume control up or down until the sounds of the ever-louder world match your liking.

Wearing the Doppler ear buds can make your commute a little easier or make the concert sound as good in section 220 as in row 1. Doppler is presenting a long-term vision of its “hearables” technology that it expects everyone will eventually use in their ears, throughout the day.

According to Doppler, the world is becoming louder by the day. However, the ear buds control what you allow into your ears. You have a volume control and an equalizer for your ears. Control the loudness of the sounds you hear, crank up the bass or even mute sounds selectively, if you do not want to hear something – a baby crying, the screech of the subway, anything. As Fritz Lanman, the executive director of Doppler expresses, it is amazing what a volume control in your ear can do.

Doppler’s companion app on the iPhone has a dial graduated in decibels. Spin it in one direction to increase the loudness and reduce everything to a whisper by spinning it back the other way. The Effects section has buttons to help you choose the ambience. You can make sounds echo several times or you can choose a reverberation just as you were on stage in Carnegie Hall.

In fact, the Doppler companion app helps you to add many effects to sound entering your ears. There is provision for mixing different frequencies. You can make the songs flange, echo or add fuzz. The integrated noise-cancellation allows turning off most sounds – there is a special Baby Suppress button. Doppler has designed this morbid-sounding mode for muting the sound of crying babies.

This is not the first time people have attempted to augment hearing as something beyond hearing aids. A hundred years ago, the inventor of the first headphones, Nathaniel Baldwin made it as an amplifier and suppressor. Others have done considerable research on this subject.

Doppler has turned all this research into something you can wear. However, nobody likes to wear hearing aids, and Doppler thinks the key to making their ear buds acceptable to people is by making it absolutely clear what these things can and cannot do. According to Doppler, the ear buds are a niche product, mostly for music lovers, allowing them to tweak a concert to their liking. They are not for 24-hour wearing and not for making phone calls.

This Drone Avoids Obstacles When It Sees Them

If you thought drones could only fly and had to be manually guided around obstacles, the information you have is about five years old. Within the last few years, drones available to the average consumer have progressed by leaps and bounds. Most drones possess an onboard computer system that allows them to navigate autonomously. They can follow along with their owner or lead a path defined by GPS waypoints, capturing alluring aerial footages on the way.

Up until now, the drones that we came across were blind to their surroundings. They were able to capture photos, but if a ski lift or a big tree got in their path, the drones did not have the capability to change course to avoid it. With the First Guidance System from DJI, all that is now relegated to history.

The First Guidance System comes with a combination of stereo cameras and ultrasonic sensors. They allow the drone to detect objects as far away as 65 feet or 20 meters and take recourse to keeping itself at a preconfigured distance. This robust sense and avoid technology not only helps to integrate drones into everyday life, but also enables ambitious projects such as the Prime Air of Amazon.

Just as the robotic driverless car does, drones can now move about towns and cities, capturing new footages, delivering packages or even handing out parking tickets. According to DJI, research teams are using their guidance system for some unique applications. For example, Fudan University at Shanghai has created an aerial solution with Intel processors for aerial detection of illegally parked cars.

A new Matrice 100 drone from DJI powers the guidance system. DJI has made the system as a developer-friendly craft that users can modify for specific tasks across different industries, even acting as a testbed for experimental work. DJI is pushing this not only at the hardware manufacturers, but also as a platform for the entire drone industry.

On the drone, you will find additional expansion bays. These allow you to add components and customize the payload, allowing it to fly with any device of your choice. For example, you can put communication tools, computing boards, sensors, cameras and more into the sky. This allows you to complete your complex jobs from a birds-eye view, while the drone gathers data.

For example, using devices from DJI or third parties, you can connect and fly the drone and transmit data to ground in real time. With dual parallel CAN ports, the Matrice 100 connects DJI devices such as the Guidance sensor systems, while Dual parallel UART ports allow connecting third party components.

You can extend the flying time of your drone by up to 40 minutes with the help of an additional battery. The adjustable arm angle for each of the four arms allows greater yaw torque and response. The rigid, strong and lightweight carbon fiber frame of the Matrice 100 offers unmatched reliability and reduces stiffness. Soft vibration-absorbing material, lining the arms, eliminates nearly all feedback from the powerful motors. That keeps all critical components stable while allowing unparalleled accuracy.

Transparent Harvester of Solar Energy

Common belief is anything that harvests solar energy must be non-transparent. Popular logic is if sunlight is allowed to pass freely through the collector, it cannot lead to energy production. Although this may be partly true for the visible spectrum of light from the sun, it must also be considered that the sun gives out radiations beyond the band of light visible to the human eye.

Therefore, even see-through solar concentrators can successfully harvest energy from sunlight. Now, a team of Michigan State University researchers has proven this by creating a transparent solar concentrator. They claim to be able to turn any window into a photovoltaic solar cell. Not only windows, any sheet of glass, including the screen of a smartphone, can be turned into a harvester of solar energy. All the while, the panel remains truly transparent.

Earlier, transparent solar cells were restricted to tinted glass or compromised the visibility. This did not become popular, as people felt rather uncomfortable sitting behind colored glass making for colorful environments. In contrast, the new solar cell from the Michigan State University is completed transparent.

At MSU, researchers used TSLC or Transparent Luminescent Solar Concentrators. These employ organic salts for absorbing wavelengths of light normally invisible to the human eye, such as the infrared and the ultraviolet light. The researchers can tune the amount and composition of the organic salts to pick up only the near-infrared and the ultraviolet wavelengths leaving the visible spectrum untouched. The organic salts make the captured wavelengths glow at another wavelength – the infrared.

The TSLC then guides the infrared light to the edge of the panel, where it encounters thin strips of photovoltaic cells, which converts it to electricity. The organic salts do not absorb or emit any light in the visible spectrum and the panel looks extraordinarily transparent to the human eye.

The process is non-intrusive and opens doors to several opportunities of deploying solar energy creatively. Tall buildings with lots of windows can benefit tremendously with this technology, as can any mobile device demanding high aesthetic quality. The biggest benefit is you can have a solar harvesting surface and need not even know that it is present.

At present, the energy producing efficiency of TSLC is rather low, of the order of 1 percent, and additional work is needed to improve its performance. However, researchers are confident they will eventually increase the efficiency to above 5 percent. In comparison, non-transparent luminescent concentrators offer efficiencies of up to 7 percent.

In July 2014, the journal of Advanced Optical Materials carried an article describing the transparent solar cells. Apart from the lead researcher Richard Lunt, Yimu Zhao, Benjamin Levine and Garrett Meek are other members of the research team working on transparent solar cells at MSU.

Lunt has cofounded a Silicon Valley start-up – Ubiquitous Energy – for commercializing the transparent solar cell. The researchers have named the technology ClearView Power. They plan to integrate it directly on surfaces of mobiles, creating an auxiliary power source. They also want to promote this as a power-producing invisible coating for windows.

Zumo-George the Raspberry Pi Behavior Driven Robot

It is difficult to forget the roving Roomba, but it is time we have a new rover – Zumo-George. It is necessary to look differently at the process of control from a series of behaviors, while defining the tenets of development driven by behavior. Development undertaken via BDD or behavior-driven development is a superior method of emphasizing collaboration and communication between testers, developers and business stakeholders. Features and scenarios define behavior, as the Gherkin syntax specifically elicits –

Given: Zumo-George is more than 10cm from wall

Situation: Power is applied to the motors

Result: Zumo-George should drive forward

Developers write the BDD scenarios before writing other code, and this determines what code is written. This process reduces wastage. In addition, the written code drives the development, which, in most cases, passes the first time. As Zumo-George executes the scenarios, developers can see exactly what steps it passes, what it fails to pass and whether it encounters any situation that they have overlooked.

Intermixed with electronics, use of BBD to program robots such as Zumo-George can be an ideal abstraction for exploring robotic control based on behavior – BDR, or Behavior-Driven Robotics. Such programming can even include testing or internal diagnostics on Zumo-George. For example,

Given: Lights are all off

Situation: When light is switched

Result: light should turn

Or, on a lighter side,

Given: Batteries are fully charged

Situation: Shoot lasers

Result: Target should fry

As Zumo-George has no laser.

Zumo-George has to execute a series of internal diagnostic tests each time it boots up. If it fails any test, then it will simply refuse to rove and will flash a red light. This will preclude the problem of the robot running out of control.

Naming the robot Zumo-George, the developers prefer referring to the robot as a “he” rather than “it.” They expect Zumo-George to mimic certain human behavior. For example, do not bump into a wall while walking/driving.

Polulu’s Zumo and the Explorer HAT Pro from Pimroni form the basis of the rover (including its name). Therefore, Zumo comes in several variants. For example, for Arduino, there is the all singing Zumo 32U4, with accelerometers, LCD, buzzers, sensors and more. Then there is the bare-bones Zumo Chassis Kit and this is most suitable for Raspberry Pi (RBPi), as users can add their own electronics.

A Smart Fridge Tells You What It Wants

Imagine you are at the grocery store and wondering what you need for the next week – if you could only peep inside your fridge now, shopping could be easier. With the new smart fridge from General Electric in your kitchen, you could use a smartphone and ask the fridge what it lacks. The smart fridge will tell you exactly how much beer, soda, milk, and even how many eggs or separate vegetables it is left with. Actually, GE ran a contest taking ideas from users that could be turned into serviceable and manufacturable accessories. They announced the winners at the CES 2015 at Las Vegas. MakerBot Industries, LLC in Brooklyn, NY, is offering not only a MakerBot Replicator, but also a 3D Printer that allows engineers, traditional product designers and even consumers to prototype their ideas rapidly. Successful designs will be manufactured at FirstBuild at their microfactory in a fraction of the time it normally takes.

GE’s ChillHub is the first major home appliance that consumers can base their prototypes on to make their own accessories for a smart refrigerator. The ChillHub can tell your smartphone how much milk is currently left, because it has a milk weighing arrangement that your phone can query when you are at the grocery store. Besides the milk weighing arrangement, the ChillHub has several USB hubs allowing you to add your own plethora of smart accessories and sensors to let your smartphone see what else you need.

For proof of concept, GE and MakerBot, in collaboration with Thingiverse, came up with the Icebox Challenge, which had about 200 entries. The first-prize winning entry was an Odor-eating Hotshot. It uses a standard box of baking soda, but maximizes its odor-canceling capabilities, keeping track of its presence in the refrigerator and alerting users when to replace it.

The second prize was a bottle holder that helps the user organize different beverages while doubling as a chip-clip that keeps bagged snacks fresh. The third prize was the Butter Pig that dispenses standard butter sticks to simplify cooking in the kitchen, measuring of recipes and making toast.

The ChillHub is suitable for adding third-party accessories because of its eight USB ports. The ports are capable of delivering up to 2A each. That makes it very easy to add accessories that can be accessed from the Internet via their built-in Wi-Fi. GE calls the ChillHub architecture a community-generated product, which is based on an open-source iOS app. This app allows users to easily access the accessories plugged into the USB ports. Other fridge owners can hack their own appliance and make DIY upgrades using the FirstBuild.

FirstBuild community members conceived the design. They used 3D printers as a means of prototyping accessories quickly. The first accessory to be designed was the Milky Weigh that tells how much milk it holds. You can buy the complete Milky Weigh from FirstBuild, or if you are more adventurous, download the entire design and 3D print the components. The Green Bean circuit board from FirstBuild provides the electronics that actually weighs the milk for Milky Weigh.

A Slice of the Raspberry Pi

The Compute Module of the credit card sized popular single board computer, RBPi or the Raspberry Pi, is not an end-user product. Manufacturers can use the device when they require an ARM-based platform to build their devices on and sell. Therefore, computing hobbyists will find it difficult to get their hands on the Module if they want to evaluate it.

The RBPi itself is readily available to anyone who wants to buy and use it for projects. However, this Compute Module is not sold as such to hobbyists and for evaluating the Compute Module, it is necessary to get hold of a real product based upon it.

Five Ninjas, some people from the RBPi Foundation and the Pi-friendly accessories seller Pimoroni has a compact media player based on this Compute Module. Their product – Slice – was the result of inspiration based on the original Apple TV.

The first Apple TV was based on the x86 and was silver colored. This was eminently hackable, unlike the later iOS running black box that Apple made. People ripped out the custom Mac OS X installed, replacing it with a Linux desktop. They then added a more open, flexible media center, which ran XBMC.

The FiveNinjas Slice Media Player turned out to be more powerful than the modified x86 version of the Apple TV. The first few Slices have just left the Sheffield assembly plant of Pimoroni. Each has a custom motherboard with a single Compute Module in a DIMM-slot.

The Slice looks like a small metal box that has a translucent plastic spacer running all round the middle. The metal of the box is anodized aluminum in one of choice of three colors – red, gunmetal and black. The entire device feels and looks very stylish. Although you cannot see inside the box through the spacer, Slice puts out a very cool light through it. The light comes from Slice’s 25 NeoPixels. These are individually addressable RGB LEDs, with each containing an in-package controller.

The Slice uses these LEDs to create a rainbow of various color sequences. These sequences are triggered as the user interacts with the Slice using its remote control. While Apple had a slimline aluminum remote, Slice has a somewhat thicker one made of plastic.

Slice has 4GB of flash, which allows it to run any Operating System without a hard disk. It actually runs OpenElec, which is a simplified Linux distro capable of booting straight into Kodi, the media application. Therefore, users can simply play video and music files on their NAS or share from their computers.

Internally, Slice has a SATA connector mounted on the underside of the motherboard. Users can put in a small 2.5 inches disk drive and fasten it on to the motherboard within the case. There are four USB ports and users can hook up Slice to their computers to mount as an external drive automatically.

Currently, there is no app to control the display of colors from the LEDs. However, one is in development and will be available soon. The Compute Module uses a powerful 900MHz Broadcom SoC with a graphics core.

Technology Allows Writing in Air

Fujitsu has made what they claim to be a lightweight and compact wearable ring-type device offering handwriting functionality and capability of reading near-field communication tags. You can wear it on your index finger, and the ring has several sensors such as a gyroscope, an accelerometer and a magnetic sensor to help with text input, apart from wireless communication functionality and an NFC tag reader. The smart ring can identify the movement the user makes with his or her fingertips as they write in the air. To begin the air-writing process, the wearer has to press an operation button on the ring with the thumb. That makes the operation single-handed.

Fujitsu had already developed a glove-style of wearable device, last year. The current device, however, compresses the entire functionality into a ring-type instrument weighing less than 10-grams, suitable for wearing on a single finger. The tiny instrument has power-saving features and operates on a single button-cell battery.

The technology developed by Fujitsu successfully corrects letterform tracings. This feature improves the accuracy of character recognition, which the user traces in air with his finger. Its success rate is 95% and the capability includes Chinese characters and numbers. The user has only to tap a finger to get documentation and instructions for working on a device with the help of the built-n NFC tag reader.

The technology from the Fujitsu Laboratories is sophisticated enough to recognize automatically unwanted connections between the strokes of a letterform when the wearer is writing a longhand trace. It corrects the data accordingly, removing the unwanted connections and this improves the legibility and text-recognition rate tremendously.

With modern advances making smart devices more miniature, along with cloud environments and efficient communication technology, there is increasing interest in HMDs or Head Mounting Devices. These and other wearable devices are very useful for people engaged in maintenance and other tasks in buildings and factories. The operator can have both hands free because of the ICT or information and communication technology used in these wearable.

Therefore, operators are no longer required to hold devices in their hands to receive information in the field. Consequently, there are high expectations from the use of such wearable devices in fieldwork that allow operators to keep their hands free to use at all times.

According to Fujitsu, the smart ring-type wearable device is targeted for use in the working world rather than at homes. At present, the company is carrying out real-world tests on the device and they have a goal of practical implementation in 2015.

Not that Fujitsu is alone in developing such finger-sized wearable technology. Others are also present in this field. For example, Logbar Inc., operating from San Francisco and Tokyo, started a Kickstarter campaign in 2013 and was able to raise close to $900,000. They have developed their Ring, which is a wearable input device capable of enabling users to text and control home appliances. Additionally, it can help the wearer complete financial transactions as well. Unlike the Fujitsu device, which is suitable for workplaces, the Ring of Logbar is meant for consumer use at home – it is not yet available for purchase, though.

The humble cable assembly

In a project, the major focus is on active components, circuit design and software, in that order. However, what we tend to overlook is the humble cable and connectors that link all the components together. Nonetheless, along with the more glamorous components, the humble cable assemblies also define the success and reliability of your project.

Active devices and test equipment, being very tangible, always seem to command greater respect compared to the attention bestowed on the almost invisible cable and connector assemblies. This is true in both the prototyping and production cycles. However, this may prove unwise in the long run. Although wireless connectivity is catching up fast, in reality, hard-wired signal interconnects are still irreplaceable and indispensable parts of nearly all systems.

Once design engineers work on the gigahertz and higher ranges in their projects, it gets more challenging for them as cable assemblies play a more active role, both practically and figuratively. The importance of cables and connectors can be seen in RF/microwave-centric web sites and publications that devote more than one-third of their ads and content to the subject. In the high-frequency world, phase matching between two nominally identical assemblies is very often critical. This arena talks about second- and third-order parameters and the temperature coefficient of the cable’s specification gains importance. High-frequency designers treat cable assemblies with respect. For them, the assemblies are energy waveguides that are carefully engineered and modeled with precise dimensions, tested and fabricated.

Just as there are many cases of counterfeit components, mostly ICs and sometimes passive, Cabling and Installer have reported fake cable assemblies as well. In fact, this was one of their top 10 articles in 2014. Fake cable assemblies do not fully meet the operating specifications. They may somehow work, but fall short at higher data rates, or they cannot provide the specified power when used for PoE.

Not only the electrical performance, fake cable assemblies compromise safety as well. In most installations, a cable’s insulation is very important factor, as it must be fire-rated so as not to support combustion. This is usually not noticed unless a fire breaks out. Some fake assemblies even substitute the necessary copper wire with a brittle aluminum core and copper cladding.

It is very easy to make fake cables, stamping them with almost any rating required. Very few people test and verify the cable performance when faced with falling data rates and rising BERs. In most cases, we remain content with the Cat5/UL rating stamped on the cable, taking them as given. This is a concern that is bothering not the high-frequency instrument manufacturers alone, but also the audio industry, the aircraft industry and electrical distribution companies. Who can say the OFHC or Oxygen Free, High Conductivity audio cable is not actually a plain copper cable slapped with an OFHC label?

With the world now reaching out to 100GHz and beyond, cables are getting thinner, tinier, with hair-thin wires, and corresponding match-head sized connectors. At such high frequencies, every bend radius, routing guide stress, torque and abrasion from sharp edges becomes important and critical.

How do fiber optic cables carry light?

Nowadays, nearly everyone is talking about fiber-optic cables. These cables are now commonly used in telephone systems, cable TV systems and the Internet. One of the main advantages with optics cables is their huge bandwidth. That means fiber optics cables can carry far more signals than copper wires can. Usually made of optically pure glass, these cables are very thin – nearly as thin as human hair. Because of their high signal carrying capacity, optical fiber cables are also used for mechanical engineering inspection and in medical imaging. Optical fiber cables are made of long, thin strands of extremely pure glass. With a diameter close to that of human hair, several strands are bundled together, to form cables that are used to transmit light signals over long distances. When examined closely, each single fiber can be seen to consist of three parts.

The central core of the fiber is made of glass and this is where the light travels. The core is covered with a cladding, which effectively reflects light back into the core. The core is surrounded by a buffer coating, mainly for protecting the fiber from moisture ingress and physical damage. Optical cables contain hundreds or even thousands of such optical fibers arranged in bundles. On the outside, a jacket, also called the cable’s outer covering, protects the cable.
In general, there are two major types of optical fibers – single-mode and multi-mode. With a small core of about 9 microns in diameter, single-mode fibers can transmit infrared laser light having wavelengths of 1,300 to 1550 nanometers. On the other hand, multi-mode fibers have core diameters of about 62.5 microns, capable of transmitting infrared light of wavelengths from 850 to 1300 nanometers.

Other types of optical fibers can be made of plastic as well. These usually have a larger core of about 1 mm diameter, capable of transmitting visible red light of wavelength 650 nm, such as from LEDs.

Light always travels in straight lines. This is easily seen when a flashlight beam is shown down a straight long hallway. You can see the entire length of the hallway until the next bend, but beyond which nothing is visible. However, placing a mirror at the corner will allow you to see round the bend. This is possible because light from around the bend strikes the mirror and reflects down the hallway. If the hallway were to be very winding with multiple bends, lining the walls with mirrors will help. Light bounces from side-to-side and travels down the hallway making the entire path visible. This is exactly how an optical fiber works.

Light travels through the core of the fiber-optic cable, constantly bouncing off the cladding. This follows a well-known principle of optics known as total internal reflection. Very little light is lost in total internal reflection from the cladding, allowing light to travel long distances within the cable.

Although the core is made from optically pure glass, some impurities remain. These degrade the light signal as it travels down the core. The extent of signal degradation depends both on the impurities present in the glass used for the core and the wavelength of the light traveling through it.