Author Archives: Andi

3D Ultrasonic Fingerprint Scanner for Improved Security

Most people are familiar with the biometric sensors used in offices and other places for checking fingerprints. So far, these fingerprint sensors were flat and sensed only 2D images of the surface of your finger. Now, researchers at the University of California, Davis and Berkeley have an improved ultrasonic 3D fingerprint sensor that measures not only a volumetric image of the ridges on fingers, but also measures the tissues beneath the finger’s skin. That makes it almost impossible to spoof.

Most smartphones now sport a fingerprint sensor to verify the authenticity of its user. Apple first introduced this technology in 2013, when it incorporated the fingerprint scanner in its iPhone 5s. Unless you have just come back from swimming, the sensor was accurate enough, and now, many other smartphones use it.

However, most of these sensors are of the capacitive type, and subject to serious security leaks. For example, you can easily fool it by placing a printed image of your fingerprint on top of the sensor. This is because the sensing is only in two dimensions. That is why the 3D fingerprint sensor is assuming such importance.

Using low-depth ultrasound, Professor David Horsley and his team has now overcome this issue. Ultrasound images the valleys and ridges of the finger’s surface and a part of the tissue under it in three dimensions. The main reasons why portable gadgets manufacturers are interested in this technology is its ultra-compact size and the capability to operate with a supply of only 1.8V.

Inspired by sophisticated medical equipment, the technology for the low-depth ultrasound technology for measuring fingerprints started to come together in 2007. This was when the researchers were working with PMUTs or Piezoelectric Micro-machined Ultrasonic Transducer arrays. Later on, they found this array to be a good fit for sensing fingerprints.

The group built their imager by embedding the PMUT arrays within a chip and integrating it. This technology is similar to the MEMS or micro-electromechanical systems that today’s smartphones already use. Using MEMS is very effective for accelerometers, gyroscopes and microphones.

According to Prof. Horsley, the chip is made from two wafers. One of the wafers contains the ultrasound parts, while the other carries the second circuit to take care of the signal processing. After bonding the two wafers, the MEMs wafer part is shaved off partially to expose the ultrasonic transducers.

The researchers explain that collection of the ultrasonic images follows the same method as that of medical ultrasound. From the chip’s surface, the transducers first emit a pulse of ultrasound and then process the echoes returning from the valleys and ridges on the surface of the finger.

Scanning a finger in 3D makes the mechanism more secure and increases the challenge several folds for those trying to get around it. As the world moves towards mobile payments, such secure systems will assume increasing importance.

When manufactured in high volumes and with modern manufacturing techniques, OEMs can expect the cost of the sensor to dip to very low levels. Apart from making better fingerprint scanners, this technology is likely to find use in personal health monitoring and low-cost ultrasonic medical diagnostics as well.

Leila and Holus – New Holographic Platforms

Who can forget that famous scene from Star Wars, where R2D2 plays a holographic video message in midair showing Princess Leila pleading for help from Obi-Wan Kenobi? While technology has not yet progressed sufficiently to achieve the Star War’s feat, recent advances in the ability to control light is opening up new possibilities for displaying 3D images.

Leila, an appropriately named company owned by David Fattal, has demonstrated a 2×2 inch holomodule as its first product. This LCD module is a 3D display capable of producing full-color 3D images and videos. You do not need special glasses to see these images and videos and they are visible from 64 different viewpoints.

Leila’s technology is based on an invention by Fattal. It utilizes advances in the ability to control the path of light at Nano-scale levels. Fattal calls this the multiview backlight and he developed this concept while working as a researcher in HP Labs. The Nano-scale structures are actually diffraction gratings.

Diffraction gratings act as tiny mirrors to reflect light in precise directions depending on the angle of the arriving beam. In practice, gratings are used to send light through cables for transmitting data. Fattal decided to use gratings to send light in prescribed directions in space, creating the basics of a holographic 3D display.

With Leila, Fattal has managed to refine the initial design for better image quality. The hologram comes out of a conventional LCD. Leila replaces the LCD backlight, which is typically made of plastic, with a more sophisticated light guide incorporating Nano-scale gratings. That means smartphones and other mobile devices will soon possess the ability to show 3D images.

On the other hand, Holus is an interactive holographic tabletop platform from the Canadian startup H+ Technology. Holus makes use of Pepper’s Ghost, an optical illusion, to reflect hidden objects in a manner that makes people believe the objects are present in the room with them. Therefore, rather than looking at a TV placed in a corner of the room, the future family will be sitting around a Holus box in the middle of the room. The Holus is a see-through tabletop box and it presents a tiny 3D digital world and allows you to interact with it.

Holus contains a see-through Plexiglas prism and projects four images of the same object onto the walls of the prism. Therefore, irrespective of the side of the prism you are on, these images collate to form a single 3D object, which you can see at different angles.

According to H+, you can feed any digital content from a computer into Holus to convert and project it as a 3D hologram-like image. You can also use motion-tracking technology to interact with the image, such as a gesture input device or a traditional gamepad. It is also possible to use the Brain Sensor electroencephalography headset from Emotiv.

The Halo tabletop box creates a social campfire experience in the home, as family members can cluster around the 3D display system, while interacting with it and with one another. On a wider scale, natural visual interaction with complex 3D images and digital content can help education immensely. Such holographic presentations will also help business activities.

A Portable Raspberry Pi Powered display

If you have a motor to control, the RasPiRobot Board is a very good fit. Apart from controlling motors, you can also use its switch mode voltage supply to power your RBPi or Raspberry Pi using a large range of battery types. Therefore, with a pack of AA type batteries and the RasPiRobot shield, you can make a very convenient and portable RBPi powered display.

To make an RBPi display that will show the current time as a scrolling text, you need to collect a few parts. These would be – the Adafruit Bicolor square Pixel LED Matrix along with its I2C backpack, A RasPiRobot Board version 2, a battery holder with on/off switch suitable for holding 4xAA batteries and the RBPi Model B+ with 512MB RAM.

Not much of wiring is involved in setting up the parts together. The only soldering you will need to do involves the LED Matrix display, as this comes in a kit form. This is not too difficult as all the instructions are included inside the kit. Once soldering is over, fit the LED Matrix display into the I2C socket of the RasPiRobot Board.

If you are using the latest version 2 of the RasPiRobot board, you have to be careful its extended header pins do not reach up to the bare connections on the underside of the LED Matrix module. In case they do, you will need to insulate the module by covering the header pins with a layer or two of electrical insulating tape.

Next, plug in the RasPiRobot Board on top of the RBPi. Just make sure the RasPiRobot board fits over all the GPIO pins on the right hand side of the RBPi. The RasPiRobot Board has two screw terminals marked GND and Vin. From the battery box, attach the flying leads to these screw terminals taking care of the correct polarity.

Fit four rechargeable AA batteries to the battery holder. Make sure they are fully charged and fitted with the correct polarity. When you turn on the switch on the battery holder, you should see the RBPi light up its power LED as well as the two LEDs on the RasPiRobot Board.

To operate the LED Matrix board from the RBPi, you will need to install the Adafruit I2C and the Python Imaging Libraries – follow the instructions here. The guide also has a few examples to allow you to check the working of your I2C interface and consequently the LED Matrix display. For example, you can have a slow display scrolling text on the LED Matrix, showing the current time.

The LED Backpack library has a number of sub-libraries that handle the low-level interface to the matrix display. The Python Imaging Library handles the job of writing text onto the display as an image. This uses the True type Font FreeSansBold size 9 from the library, although you can use other fonts as well that look good. You may need to experiment with the fonts, as they are not primarily intended to be displayed in the 8×8 pixels the matrix uses. You can select the color of the display also.

The RasPiRobot Board for the Raspberry Pi

In robotics, it is usual to have to drive a few motors with the RBPi or Raspberry Pi. However, instead of letting the RBPi handle the low-level job of motor control, using a motor controller board is another option. This frees the RBPi for handling more of the high-level code, resulting in better utilization of the resources and improving the efficiency of the project.

For turning your RBPi into a proper motor controller, you can use the RasPiRobot Board. Apart from simply running your motors from an external supply, the RasPiRobot does a fantastic job of powering your RBPi as well. A switch-mode power supply on board the RasPiRobot ensures that your RBPi receives a well-filtered and regulated power supply.

To run two motors from the RBPi, you will need a few parts. These include a battery holder with a switch – capable of holding six batteries of the AA type, two 5V or 6V DC motors, a RasPiRobot Board v2 and an RBPi Model B+ with 512MB RAM. You will find the version 2 of the RasPiRobot Board perfectly matches the RBPi Model B+. The RasPiRobot Board fits directly over the RBPi, with its GPIO connector matching the GPIO pins of the RBPi.

The RasPiRobot Board uses the L293D motor driver chip in an H-bridge configuration to run two DC motors independently and bi-directionally. The switch-mode power supply on board allows you to drive low-voltage DC motors from a higher voltage battery supply. Additionally, the RasPiRobot Board can also supply the RBPi with over 2A of current. That means you need only a single power supply for driving both the motors and the RBPi.

You must connect the motors via the screw terminal pairs on the RasPiRobot Board. These terminals are marked as L and R on the board. Take care to connect leads from one motor to the L terminals and the leads from the other motor to the R terminals. Swapping the leads of a particular motor will make it spin in the reverse direction.

Now plug in the RasPiRobot Board on the RBPI, taking care to match the GPIO pins and connector correctly. After this, you may connect the flying leads from the battery pack to the screw terminals. Be careful to connect the positive lead (red/yellow color) to the screw terminal marked Vin and the negative lead (black/blue color) to the screw terminal marked GND. Reversing these leads could result in irreversible damage to your RasPiRobot Board.

Place the batteries in the holder (be careful of maintaining the sequence), and throw the switch to the on position. The RBPi starts to boot, which is evident from its LED lighting up. The two LEDs on the RasPiRobot Board should also light up. You will need to download and install the Python Library – follow the tutorial.

After the library has installed, you can get the motors running individually in forward or reverse directions for a definite interval or stop them. It is also possible to make your entire assembly mobile by mounting it on a robot chassis.

IDEASTICK: Windows Goes Into Your Pocket Now

At last, users of the Operating System Windows will also be able to enjoy the simple portability that Linux users already have. Lenovo has come up with an oversized memory stick – the new Stick 300. Actually, instead of being just an oversized memory stick, Stick 300 is full-fledged Windows PC. Although the specifications are rather low-end, the ideastick from Lenovo makes it up with being portable and having a more appealing price tag.

Obviously, the tiny chassis cannot offer an exciting hardware. However, Stick 300 runs on an Intel Atom Processor, Z3735F, with 2GB of RAM and has 32GB of storage. And, with the ideastick Stick 300, you can transform your HDMI-TV or monitor into a fully functional Windows PC. Since Stick 300 is only 100x38x15mm in dimension, it is portable and affordable. You can easily take it along when on vacations and use it as a media hub.

Initially, Stick 300 will ship with Windows 8.1, but it will be eligible for a free upgrade to Windows 10. You do not need to bother about connectivity, as Stick 300 has both Wi-Fi 802.11 b/g/n and Bluetooth 4.0 built-in. It also has a micro SD card slot and a tiny speaker.

Stick 300 is comparable to other products in the market. This includes Compute Stick from Intel, which they had released in March and an Ubuntu Linux powered lower-end option. Therefore, if you are in the market looking for an ultra-portable Windows solution, Stick 300 is a simple and functional option.

On its side, the Stick 300 has a USB 2.0 socket, which allows you to use your keyboard and mouse wirelessly; that is, if your monitor or TV is not touch-enabled. Powering up is through a second micro USB port. The hardware included is good enough for browsing the web, watching Netflix and even doing some light gaming. Therefore, instead of lugging along a hefty notebook on the road, you can conveniently carry the Stick 300 and plug it into a TV in a hotel for a spot of catching up.

In comparison, Compute Stick from Intel is also an entire PC crammed inside an HDMI stick, which you can fit in your palm. The Compute Stick instead uses an Intel Atom quad-core processor. It has a full-fledged USB 2.0 port on one side and a micro USB port on the other for powering up. However, the Lenovo Stick 300 is $20 cheaper.

If you can do with somewhat lower specifications, there is another stick with the Ubuntu 14.04 LTS OS on it. Since it has 1GB RAM and 8GB internal storage, the Ubuntu stick is less expensive than those from Lenovo or Intel. For keeping it cool, the Ubuntu stick has vents on top and sides. It also has a tiny fan for circulating air.

You may have to use the included HDMI cable to connect the stick to your TV, as most TVs do not have much space surrounding the HDMI socket that will accommodate the width of your portable stick computer. In addition, since all these sticks have only one USB port, you will need a unifying wireless solution – such as from Logitech – to get both your keyboard and mouse connected.

Controlling Robotics Through Brain Waves

Imagine moving things about with nothing more than just your brain waves. This is not some science fiction movie with an exaggerated depiction of an obscure term called Telekinesis – the art of moving matter with thought. Some 15-20 patients have joined studies of brain implants that can convey information from the brain to a computer. These include patients in advanced stages of ALS and those completely or partially paralyzed.

All the patients have undergone similar tests conducted by BrainGate, a closely related study. Some patients, totally unable to move to speak, have so far regained some ability to communicate because of electrodes implanted in their brains. A Georgia company called Neural Signals has developed the electrodes.

In 2011, the US Food and Drug Administration loosened its rules for testing “fully pioneering technologies” such as brain-machine interfaces. Since then, one-third of the patients have undergone surgery for inserting implants into their brains. Other human experiments under way, such as at Caltech, are trying to offer patients autonomous control over Android, the tablet operating system from Google.

Another team, at the Ohio State University is collaborating with Battelle, an R&D organization, for inserting an implant within a patient. They intent to use the brain waves of the patient to control stimulators attached to the arm. According to Battele, They aim to reanimate the paralyzed limb via voluntary control of the patient’s thoughts.

Whenever someone intends to move a limb, a few dozen cells in his or her brain generate electrical activity that can be easily recorded. That gives a fairly accurate picture of what the brain intends to do. Although the brain contains billions of neurons, scientists have been able to sample a couple of hundred of them to get some signals.

Although still experimental, the neural engineering program at the National Institute of Neurological Disorders and Stroke initially developed the technology to study animals in physiology labs. They have refined this to a point where the technology can be applied to humans as well.

A bundle of wires leading from the human patient’s cranium reaches a bulky rack containing signal processors, amplifiers and computers. The apparatus enables lifelike movements in the dexterous hand and fingers of a nine-pound robotic arm. However, the movements are finicky and somewhat dangerous, breaking frequently because of loose connections.

According to John Donoghue, a neuroscientist at the Brown University leading the BrainGate study, today’s brain-machine interface is similar to that of the first pacemakers. They too had wires punched through the skin, reaching the heart and were connected to carts full of electronics. He says brain-machine interfaces today are at the start of a similar trajectory, and will ultimately reach a stage such as that of the present-day self-contained pacemaker, powered by a long-lasting battery.

Researchers were able to demonstrate practical activities – the tasks of daily living, something that most of us take for granted, such as brushing teeth. They examined the patient’s abilities using the Action Research Arm Test, where the patient scored 17 out of 57 in dexterity tests. This was about similar to results that someone with a severe stroke would have obtained.

Devices Running on WiFi Power

Mobile devices are now radically smaller and more powerful than those available in the last decade were. They are also able to tackle more technology-related tasks compared to their erstwhile brethren. However, as their capability grows, they need to consume more power. With the Internet-of-Things and wearable technologies gaining increasing recognition from users, the need to keep them ‘on’ all the time is raising the topic of the best methods to power them.

Imagine that you have multiple sensors embedded around your home, tracking temperature changes by the minute and governing your thermostat to help conserve energy. How nice it would be if all the sensors operated without batteries. For then, you could rest assured that they, in tandem with the thermostat, will be properly monitoring the energy consumption. With battery-operated sensors, you will need to check on the status of each sensor frequently to prevent the system going haywire.

Now, engineers have developed a new communication system that does not require batteries to operate it. Instead, it uses existing Wi-Fi infrastructure and radio frequency signals to provide Internet connectivity to devices. Very soon, your battery-less wristwatch or other wearable devices will be able to communicate directly with other gadgets for storing information about your daily activities on your online profiles.

Earlier research by a group of engineers at the University of Washington had shown that it is possible for low-power devices to run off wireless waves such as those belonging to radio and TV. Their most recent work has taken them a step further. Now these devices, apart from operating without batteries, can send their signals to laptops or smartphones, using only wireless waves to generate the required power.

According to Shyam Gollakota, an assistant professor at the University of Washington, this is an essential step for Internet of Things to really take off. Potentially billions of battery-free devices will need connectivity when embedded in everyday objects. The research can now provide WiFi connectivity to devices and they claim their process consumes several orders of magnitude less power than that typically required for WiFi connectivity.

A tag made by the researchers listens for WiFi signals that a local router exchanges with a laptop or a smartphone. An antenna on the tag selectively reflects or absorbs the signal to encode it. The activity produces tiny changes in the signal strength of the radio waves that other devices can detect and decode.

The method allows central devices such as laptops, tablets and smartphones the ability to communicate with other low-power devices and sensors. The central devices exchange data with sensors that lie within a range of about two meters and do so at the rate of one kilobit per second. For example, a pair of smart socks could relay information about your jog to the jogging app on your phone. Although there is a chance for the radio signals to be buried in noise, the system works because the devices know the specific pattern that they need to look for.

That allows low-power Internet of Things to communicate easily with a large swarm of devices around them because of the prevalence of WiFi.

Raspberry Pi for the Talking Chatter Smartphone

You may have seen and even played with the Chatter Telephone, as the classic Fisher Price toy has been around since 1962. Although the design of the toy evolved over the years, in 2010, the Disney/Pixar film Toy Story 3 managed to depict the Chatter phone in its original classic form. Coinciding with the release of the movie, Fisher Price updated their model as the Talking Chatter Telephone. The new model carried some voice clips from the movie and had an all-plastic body, reminiscent of the boxy shape of the 1960’s original model.

Grant has used the famous Raspberry Pi or RBPi single board computer to turn the Talking Chatter Telephone into a Talking Chatter Smartphone. The modified phone gets its enhanced brains from an RBPi Model B+. All the logic comes from a Python script that runs on startup and access to the network is via a tiny Wi-Fi dongle. To retain the original factory look of the phone, Grant has avoided adding unnecessary buttons or screen and retained the original components and controls for interaction.

Internally, Grant has added a sensor to the hook cradle, but retained the original rotary dial that controls playback of the movie clips. For the eye movements, he has added a servo, while retaining the built-in speaker for providing audio output. He has retained the three micro switches the dial uses as a digital encoding system to sense the five dial positions. The RBPi replaces the battery box and the original PCB.

The phone pulls data from various online services via JSON format APIs. As of now, it connects to Forecast.io for receiving weather information and to Rotten Tomatoes for information on movies. However, one can easily extend this to other APIs as well. For example, the phone could be made to swap APIs for weather forecast with APIs providing current exchange rates, stocks or a Quote for the Day.

The phone also has a push notification system that uses a Twitter account. Grant uses it to pull new alerts from that account and to push them onto the account using IFTTT. He uses pre-defined alerts or recipes that he drives from his iPhone. For example, the IFTTT alerts the phone when Grant leaves work, there is rain forecast for tomorrow, the garden temperature is getting close to 10°C and when the International Space Station is about to pass overhead.

Grant has given the Chatter Smartphone a Wall-E startup sound for its boot up. That serves a dual purpose as the RBPi makes the sound when it has finished booting and lets Grant know that it is ready for an SSH connection. According to Grant, this should be made a standard feature for every RBPi. If you feel the volume of sound is low, it is easy to extend the RBPi’s audio jack to the back panel of the phone. This has the added potential of turning the Fisher Price phone into a high-end hi-fi system.

Using a Bluetooth add-on for the RBPi it is also possible to extend the audio to powered Bluetooth speakers outside the phone – making it wireless.

Using Raspberry Pi for Dog Training

Dog lovers and those who keep dogs as pets know that every dog has its own personality and like us humans, they too, often succumb to temptations. Some canines just cannot resist chewing those delicious new sandals, while others must investigate the leftover food scraps on the dining table. And, as working people cannot monitor their pet’s behavior the whole day, Dave Young took up a project involving lasers and the single board computer, the Raspberry Pi or RBPi, to help their pet keep its nose out of food scraps.

Dave Young’s Laser Dog Watcher consists of a laser tripwire, which silently alerts the RBPi as soon as the dog trips the invisible beam. The RBPi then takes a snap of the situation and plays an audio clip to dissuade the dog from its intentions. The project borrows the laser tripwire from an earlier design of a silent doorbell that Dave had installed at his home.

The laser tripwire system is of a simple reflection type. Both the laser source and its detector are in the same enclosure on one side of the room. On the other side is a small mirror placed to reflect the laser light back to the photo-resistive detector. Anything interrupting the beam also trips the detector, which sends out a signal. As ambient light plays an important role when detecting interruptions of the laser beam, Dave added a threshold level adjustment. In addition, to make it easier for the laser to hit the detector, he added a Fresnel lens in front of it.

The tripwire system is wirelessly linked to the RBPi. For this, Dave used an XBee module, series 1 by Digi, who has a starter kit for users. The integrated AD converter on the module transmits the detected light level digitally, which serves two purposes. Setting the threshold level for detection becomes simpler and there is no noise involved as during an analog transmission.

The XBee interface transmits the digital value to the receiver as a PWM signal. The XBee receiver filters this PWM signal to produce a DC voltage level. You need a second AD converter to translate the DC voltage level to a digital value. Although this method of converting the signal twice is somewhat cumbersome, the XBee module makes it very easy to create the wireless link.

XBee provides their XCTU setup utility, which helps in setting up the XBee radio transmitter and receiver. The starter kit also includes an XBee USB Adapter board that connects to the RBPi, which may need FTDI VCP or Virtual Com Port drivers.

When there is a break in the laser beam, the XBee radio alerts the RBPi, which then triggers its GPIO to play an audio file as well as takes a photo with the Pi camera. The audio file changes so that the dog does not get accustomed to the same reprimand each time it tries to break the rules. According to Dave, the camera is not essential, but it serves to detect false alarms and to record the surprised look on the dog’s face.

SOLI: The Final Interface is Your Hands

Finally, it is time to say good-bye to buttons and touchscreens. You need only wave your hands in thin air for controlling your gadgets. This game changer is a breakthrough from Google and is its project Soli. Soli makes it a thing of past to hit incorrect keys with your thumbs and you can conveniently forget swiping screens. The new gesture technology from Google is very precise and allows working on the smallest of displays.

Soli has small chips generating invisible radar to recognize finger movements. The chips are small enough so that they can be embedded into wearables and other devices. The deciphered finger movements are then translated into commands that computers can understand.

The system identifies delicate finger movements using the radar coming from tiny microchips. The system can use gestures to create touchpads, virtual dials and more as shown in the video above. Although there are camera-based sensors, such as Leap Motion, to capture gestures, they are cumbersome to set up requiring special hardware.

The inventor of this technology is Mr. Poupyrev, who heads the team of designers and developers at Google’s ATAP or Advanced Technology and Projects Lab in San Francisco. According to the Russian inventor, the beauty of Project Soli is the chip that can be embedded into just about anything and the use of invisible radar emanating from it.

Typically, police use the smallest radar for speed traps and even these are the size of a shoebox. The team had to struggle hard to shrink that radar to fit it inside a microchip. Although it took them 10 months, Mr. Poupyrev and his team were able to shrink all the components of radar down to millimeter size. They worked with Infineon, the German chipmaker and were inspired by the advances made in Wi-Gig, the next generation communication protocol for Wi-Fi.

Soli is a simple technology and the lack of cameras makes it easy to put wherever you want – in a toy, watch, wearable computer, car, furniture or anywhere. It is useful whenever people want to connect with devices. For example, Soli technology makes it possible to interact with objects in games making use of VR or virtual reality.

Since Soli makes it possible to replace a physical device, it works perfectly for Virtual Reality, as the field of vision of the user in VR is limited. The microchip uses radar to recognize movements of fingers. The chip radiates a broad beam radar for recognizing movement, distance and velocity. The radar uses the 60GHz spectrum and captures about 10,000 frames per second. The chip then translates the movements into commands that computers can understand.

Once Project Soli becomes reality, in the future we will be able to control devices such as fitness trackers and smart-watches only by our finger movements and will not require smart-phones as of now. Very soon, you may simply be able to snap your fingers to switch on the lights in your room and to vary its intensity by twirling your fingers.