Category Archives: Newsworthy

Diamondoids Make Three Atoms Wide Wires

At the SLAC National Accelerator Laboratory of the Department of Energy, and the Stanford University, scientists have discovered a new method of using diamondoids. These extremely tiny bits of diamonds, these diamondoids can be used to assemble atoms into the thinnest possible electrical wires—only three atoms wide.

The diamondoids do this by grabbing different types of atoms and bringing them together as is done in LEGO units. The scientists are of the opinion this new technique has the potential of creating tiny wires suitable for a wide range of applications. This could include fabrics for generating electricity, superconducting materials for conducting electricity without any loss, and optoelectronic devices employing both light and electricity. The scientists have reported their findings in Nature Materials.

According to Hao Yan, a lead author of the paper and a postdoctoral researcher at Stanford, the process self-assembles tiny, conductive wires of the smallest possible size. The process involves simply dumping the ingredients together, with the results coming in only half an hour.

The researchers have made an animation to show the molecular building blocks joining the tip of the growing nanowire. In each block, there is a diamondoid, attached to sulfur and copper atoms. Just as LEGO blocks do, the diamondoids only fit together in specific ways that their shape and size dictate. While the insulating diamondoids form an outer shell, the sulfur and copper atoms make up a conductive wire in the center.

Although several methods exist for self-assembly of materials, the method with diamondoids is the first one to make a nanowire with a solid, crystalline core. According to a co-author of the study Nicholas Melosh, the core also has good electronic properties.

The semiconducting core of the needle-like wires—a combination of copper and sulfur, known as chalcogenide—is surrounded by an insulating shell formed by diamondoids.

According to Melosh, this miniscule size is very important. In reality, the material exists in only one or two dimensions—as wires or sheets of atomic-scale dots. At these dimensions, the material has very different properties, extraordinarily different compared to those of the same material when made in bulk. With the new method, researchers were able to assemble the materials with atomic precision and control.

The scientists used the diamondoids as assembly tools, as these are tiny, with interlocking cages of carbon and hydrogen. The SLAC laboratory extracted and separated the diamondoids by size and geometry from petroleum fluids, where the diamondoids occur naturally. Melosh and professor Zhi-Xun Shen from SLAC/Stanford are leading a SIMES research program over the past decade. They have found several potential uses for the diamondoids. This ranges from making tiny electronic gadgets to improving electron microscope images.

The research team found that tiny diamonds attract each other strongly—through van der Waals forces—a fact they exploited. Because of this attraction, the microscopic diamondoids can clump together much the same way as sugar crystals do, this being the only reason they are visible to the naked eye. The scientists started with the smallest possible dimensions of the diamondoids. They used single cages containing just 10 carbon atoms, to each of which they attached a sulfur atom. When the sulfur atom bonded with a single copper ion, it created the basic building block for a nanowire.

Tinker Board: Raspberry Pi Competitor from ASUS

The community of single board computer users is passionate and the DIY enthusiasts are growing daily. While they are infatuated with the amazingly tiny package called the Raspberry Pi (RBPi), they are constantly clamoring for more performance and connectivity features. This demand has produced several competitors to the RBPi, and the tech giant, ASUS Computers is now providing one in the form of a Tinker Board.

The ASUS Computers product is a mini-PC based on the ARM core, and its actual model number is the ASUS 90MB0QY1-M0EAY0. However, it is easier to remember it as the Tinker Board. The smart name from ASUS for the product is the exact demographic of its intention, offering a tiny, all-in-one product for makers and tinkerers, to use in media servers, fun projects, and embedded applications. For instance, the Tinker Board allows one to build a personal NES Mini alternative.

Although a 64-bit ARM Cortex-A47 quad-core processor, the Broadcom BCM2837, powers the RBPi3 at 1.2 GHz, a 32-bit ARM Cortex-A17, the quad-core Rockchip RK3288 processor powers the Tinker Board, operating at 1.8 GHz. ASUS claims the Tinker Board is almost twice as fast as the RBPi3 model B. Additionally, against the 1 GB RAM configuration of the RBPi3, the Tinker Board offers 2 GB of RAM.

The Tinker Board has other advantages as well. The hardware includes the complete H.264 4K video decode capability, supported by a far stronger graphics performance from the ARM Mali-T764 with a graphics core of the Rockchip RK3288. The audio capabilities are also better with the Asus minicomputer offering audio sample rates at 192K/24-bit, while the RBPi3 offers only 48K/16-bit, which necessitates an add-on board for HD audio from the RBPi3.

The integrated, Gigabit Ethernet port at full speed on the Tinker Board gives it a substantial boost over the 100 Mb LAN on the RBPi3. Similar to that available on the RBPi3B, the Tinker Board also has an 802.11b/g/n Wi-Fi and Bluetooth 4 capability. In addition, it has support for SDIO 3.0, and offers swappable antennas for the built-in 802.11 b/g/n Wi-Fi module.

Similar to the RBPi3B, the Tinker Board also supports the Debian Linux (modified by ASUS) operating system and KODI, with its slick media streaming interface. Similar to the RBPi, the Tinker Board also comes with no on-board storage, and you have to use a micro SD card. However, the additional capabilities on the Tinker Board make it about twice as expensive as compared to the market price of the RBPi3B.

Physically, both single board computers are of the same size, with mounting holes in the same position. Obviously, ASUS wants the Tinker Board to be a drop-in replacement for the RBPi3. The same configuration of the GPIO pins for both boards lends further support to this credence.

The RBPi concept has spawned a whole new era of tiny computer devices, selling in several schools, colleges, and universities. Many other device manufacturers have since piled on and released their own version of the credit-card sized powerhouse.

In this chaotic, crowded environment, the specifications of the Tinker Board, although not ground breaking, could play nicely in the existing RBPi-based projects.

Soft Robots Mimic Biological Movements

At Harvard University, researchers have developed a model for designing soft robots. The special features of these robots include bending as a human index finger does and twisting like a thumb when a single pressure source powers the robots.

For long, scientists have followed a process of trial and error for designing a soft robot that moves organically—twisting as a human wrist does, or bending just like a finger. Now, at the Wyss Institute for Biologically inspired Engineering and the Harvard JA Paulson School of Engineering and Applied Sciences, researchers have developed a method for automatically designing soft actuators that are based on the desired movement. They have published their findings in the Proceedings of the National Academy of Sciences.

To perform the biologically inspired motions, the researchers turned to mathematics modeling for optimizing the design of the actuator. According to Katia Bertoldi, Associate Professor and coauthor of the paper, now they do not design the actuators empirically. The new method allows them to plug in a motion and the model gives them the design of the actuator that will achieve that motion.

Although the design of a robot that can bend as a finger or a knee does can seem simple, it is actually an incredibly complex process in practice. The complications of the design stems from the fact that one single actuator cannot produce the complex motions necessary. According to the first author of the paper, Fionnuala Connolly, who is also a graduate student at SEAS, the design requires sequencing the actuator segments. Each of them performs a different motion, with only a single input actuating them all.

The team uses fiber-reinforced, fluid-powered actuators. Their method uses mathematical modeling for optimizing the design of the actuators, which perform a certain motion. With their method, the team was able to design soft robots that bend and twist just as human fingers and thumbs do.

SEAS have developed an online, open-source resource that provides the new methodology in the form of a Soft Robotic Toolkit. This will assist educators, researchers, and budding innovators in designing, fabricating, modeling, characterizing, and controlling their own soft robots.

The robotics community has long been interested in embedding flexible materials such as cloth, paper, fiber, and other particles including soft fluidic actuators, which consist of elastomeric matrices. These are lightweight, affordable, and easily customizable to a given application.

These multi-material fluidic actuators are interesting as the robotics community can rapidly fabricate them in a multi-step molding process. Only a simple control input such as from a pressurized fluid achieves the combinations of extension, contraction, twisting, and bending. Compared to the existing designs, new design concepts are using fabrication approaches and soft materials for improving the performance of these actuators.

For instance, motivating applications are using soft robotics such as heart assist devices and soft robotic gloves for defining motion and forcing profile requirements. It is possible to embed mechanical intelligence within these soft actuators for achieving these performance requirements with simple control inputs. The challenge lies in the nonlinear nature of the large bending motions the hyper-elastic materials produce, which make it difficult to characterize and predict their behavior.

LCD Touchscreens for the Raspberry Pi

Those using the single board computer, the Raspberry Pi (RBPi), can now get several high-resolution LCD screen models on the market. While they are cheap, some are designed to integrate with the RBPi specifically. SunFounder, a company specializing in accessories and kits for RBPi and Arduinos, produce a series of these screens. For satisfying different segments in the market, SunFounder has lately produced and is marketing a number of models with varying price ranges.

SunFounder LCD 10.1” HD

With a resolution of 1280×800, this high definition LCD is a true gem for RBPi fans. The screen has appropriate screw supports for use as a desktop screen. If you remove the supports, the screen can be used in any other context as well. The rear of the screen has a compartment with an electronic screen presenting input connectors in other formats such as VGA and AV, including HDMI. The back also has provision for mounting the RBPi and fixing it with screws. As the networking sockets and USB ports of the RBPi remain at the edge of the screen, cable connections are not hindered.

This high quality display has low weight and is highly adaptable to other purposes. That means you can screw it on different types of support, for which it has adequate arrangements. The viewing angle is also very good, and one is not forced to look at the upper front of the screen to be able to work with this model.

SunFounder LCD 7” HD

Significantly cheaper than its 10” elder brother, this 1024×600 TFT LCD is very compact and has convenient dimensions. However, it has a smaller viewing angle, considering this is purely a desktop model. Apart from HDMI, the LCD accepts inputs such as VGA, AV1, and AV2.

Kuman LCD 7” HD

Technically identical to the SunFounder 7”, this LCD is equipped with a touch screen. As this is somewhat cheaper, the 1024×600 Kuman TFT LCD is more economical. However, it is slightly heavier than its rival is. It accepts HDMI, VGA, and AV inputs.

SainSmart LCD 7”

If you are looking for something still cheaper, and able to sacrifice some resolution, the SainSmart model should appeal to you. At a resolution of 800×480, this TFT LCD also includes a touch screen. However, this is not a desktop model, and you must arrange for a suitable housing. Weighing considerably lower than the others do, it accepts inputs in the form of HDMI, VGA, AV1, and AV2.

Raspberry Pi LCD 7”

Although officially released by the Raspberry Foundation, this 800×400 LCD model is comparatively expensive. However, it comes with a touch screen and has a video shield for the RBPi boards. The case housing must be purchased separately, which adds to the cost.

Kuman 7”

If you are looking for a model you can assemble, this 800×480 model from Kuman makes that possible. This is the same as the other Kuman model, but less expensive. Additionally, it has a touch screen and a remote control. It accepts input formats such as HDMI, VGA, and AV.

3D Printers: Change the Shape of Your 3D-Printed Objects

When you print 3D objects on your 3D printers, they remain stable. Other than deteriorating over time, the objects do not change by themselves. However, that may be changing now. Scientists at MIT have created a new technique of printing 3-D objects where you can change the polymers in the object after printing. That means change the color of the object, grow or shrink it, or even change its shape entirely.

Associate Professor of Chemistry at MIT, Jeremiah Johnson led the research, along with Postdoc Mao Chen, and graduate student Yuwei Gu. They have written a paper on the findings, and they call the technique living polymerization. According to the team, the process creates materials whose growth can be stopped and started at will.

As they explain, after printing the material, it is possible to morph it into something else using light, even growing the material further. For instance, the team used a 3-D printed object immersed inside a solution. When they shined Ultra Violet light on the object, while it was still immersed, the resulting chemical reaction released free radicals. The free radicals bound themselves to other monomers within the solution and added them to the original object. According to the team, the process was highly reactive, and damaged the object.

At another study at the Wyss Institute for Biologically inspired Engineering of Harvard University, Dr. Jennifer Lewis is a senior author on a study on shape-shifting objects created using a 3-D printer. The team has devised a technique that allows printed objects to change their shape according to the environment.

According to the researchers at Wyss Institute, the printer creates a structure that can shift its shape. For instance, when immersed in water, the structure folds into complex and beautiful designs. The researchers claim they can adapt the process so that the printed object can fold into prescribed shapes when cooled, heated, or injected with an electrical current.

The researchers are of the opinion the technology could pave the way for generating new types of medical implants. Folding into shape when inserted into the body, such implants could generate a new family of soft electronics. According to Dr. Lewis, this is an elegant advance in the assembly of programmable materials, which a multidisciplinary approach made it possible to achieve. This has taken them farther than merely integrating form and function for creating transformable architectures.

The researchers have published their work in the journal Nature Materials. They say they were inspired by the manner in which plants grow and change their shape over time, as plants and flowers contain microscopic structures as tissues allowing them to change their shape as their environment changes. For instance, depending on temperature and humidity, plant leaves, flowers, and tendrils open or fold up.

Dr. Lewis used a printable hydrogel as it swells when added to water. The team designed specific structures under control that would change shape when placed in water. They derived the hydrogel ink from wood, and the ink had cellulose fibrils very much like the structures in plants that allow them to change shape.

IOT: The Internet of Things Helps Manage Decisions

In any era, one of the characteristics of a good leader has always been their ability to take a good decision with the limited information available to them. According to the 26th US President Theodore Roosevelt, the best thing to do in a moment of decision is doing the right thing, the next best thing is doing the wrong thing, while the worst that anyone can do is doing nothing. This brings us to the IOT

Expectations are the Internet of Things (IoT) will be networking billions upon billions of things someday. Even if considering this hype, there is no ignoring the fact that IoT is already affecting management decisions worldwide. Business managers, at all levels, are receiving information that is more relevant as soon as they need it. Connected devices are making this possible, coupled with advances in collection of data and analytics. All that is affecting the decisions they are making, and business performance and operation is seeing a deep and lasting impact.

The broad range of nascent and mature technology available with the Internet of Things ranges from microscopic sensors called smart dust, to autonomous robots, to remote monitoring and RFID tags. Predictions from Gartner forecast that from the 6.4 billion connected IoT devices in 2016, the year 2020 will witness a jump to 21 billion devices worldwide. That means over the next five years, the number of internet-connected things will swell by three times.

Keeping this explosive growth in mind, Industry Week has conducted a study—the Industry Week Industrial Internet of Things Analytics Research Study. It gauges the usage of present and future state of IOT technology by US manufacturers. It also includes a special focus on data collection and analytics, as the IoT is more about the ability to collect, analyze, and use the massive amounts of data generated by the devices rather than about the devices themselves.

For their research, Industry Week has defined the Internet of Things as products and machines containing embedded electronics and sensors, with software for network connectivity that enables control and remote data collection. They also define analytics as the process of extracting insights from raw data, enabling better decision making.

The study reveals more than half the manufacturers reporting they are currently using the IoT technology for collecting machine data. Other companies say they are collecting the data from sensors embedded within their products—the percentage here is smaller, but significant at 44%. Both groups are using the data from machine and product for generating management reports and for performing root cause analysis as and when problems crop up.

According to the study, less than 25% of the manufacturers are using IoT for purposes that are more proactive. This includes improving business decision making through data mining or development of optimization models. All this indicates the presence of a potential source of competitive advantage as well as a huge opportunity.

Surprisingly, about one third of the manufacturing leaders said they did not have any strategy specifically geared towards the Internet of Things. However, most of these manufacturers reported their senior leaders are driving the organizations to be more data centric and analytical.

Bipedal Robots Walk Agilely on Two Legs

At the New Economic Summit (NEST) 2016 conference, in Tokyo, Japan, Andy Rubin unveiled an awesome new bipedal robot from SCHAFT. The new robot can easily climb stairs, carry a payload weighing 60 kilos, balance on a pipe, and move in tight spaces. In fact, they even showed a video where the robot can be seen climbing a narrow staircase. By positioning its legs behind its body, the robot is shown cleaning the stairs using a spinning brush and a vacuum type appendage attached to its feet. The video also shows the robot outdoors, negotiating snow, slippery rocks, and rough terrain.

According to the SCHAFT representative, they have not yet announced the robot product, and neither have they named it yet. However, the robot will be a low-cost, low power consumption, compact device that will help humankind. Incidentally, travelling over uneven terrain, tackling stairs, and lifting weights are notoriously difficult for robots.

Engineers also find it tough when deigning bipedal robots. Although one of the main advantages of making a bipedal robot in the first place is to make it adapt to uneven terrains, it also has to be steady and self-balancing. However, as Agility Robotics has demonstrated, bipedal robots can be agile too.

Coming as a spinoff company from the Oregon State University, Agility Robotics have named their bipedal robot as Cassie. Earlier, the firm’s researchers had Cassie’s predecessor, ATRIAS. In a demonstration video, ATRIAS played a slightly one-sided game of dodge ball.

According to the researchers, the robot ATRIAS was the first to exhibit gait dynamics that were surprisingly human-like. Although ATRIAS implemented walking with a spring-mass, it did not serve any purpose other than being the practical machine for a science demonstration. The researchers explained spring-mass walking as a passive mechanism mimicking the human muscles by using the elasticity of springs.

Agile Robotics has improved this mechanism with Cassey, while also adding a hip joint with three degrees of freedom. That allows Cassey to steer more easily. Cassey also has powered ankles, which means it can stand still without having to jig from one foot to the other. Agile Robotics is now mocking up a possible final design for Cassey as a consumer model.

It is interesting to consider how useful such a bipedal bot could be. Compared to a wheeled robot, a bipedal robot walking on two legs may be a complex engineering achievement. However, that means the robot can go pretty much anywhere a human can. That includes stairs, rocky grounds, anything a human can tackle.

According to Agility Robotics, Cassey and similar bots can be used for search-and-rescue operations, in areas dangerous to humans. If the bots are cheap enough, doctors can use such robots to help improve exoskeletons or prosthetic limbs. Another suggestion is to use these bots for delivering packages. However, the bots may need to have an additional telescoping stick for poking at doorbells.

Although still in the future, these bipedal robots will be useful in space exploration, walking and mapping unknown terrains. Another area where they would be welcome is in the nuclear applications, such as when cleaning up after a nuclear disaster, as the bots could be designed to remain unaffected by high doses of radiation.

Researchers Develop Thermoelectric Organic Transistors

Linkoping University scientists have made possible an organic transistor that is driven by temperature changes instead of by an electrical signal. Made of a thermoelectric material, the transistor brings about an appreciable current modulation for just a single degree rise or fall in temperature.

Professor Xavier Crispin, based at the Laboratory of Organic Electronics of the university, states that heat driven transistor is the first logic circuit to be developed that makes use of thermoelectricity.

Wide Range of Applications

The scientists foresee diverse uses for the new transistor. Since the device can record very small temperature changes, healthcare professionals can use it to fabricate therapeutic dressings that monitor the healing process along with treating the patient.

The scientists say it would be possible to build circuits that would respond to the heat contained in infrared radiations, too. This could be of particular use in developing heat cameras and similar devices.

The organic transistor is highly susceptible to minute heat changes. Compared to conventional thermoelectric devices, it is 100 times more sensitive to a drop or rise in temperature. This high level of heat sensitivity implies that just one electrical connector from a heat sensor electrolyte is adequate for sending a signal to the transistor. The researchers explain that a pair of a thermoelectric transistor and a sensor connector would be sufficient to make up a “smart pixel” for the camera.

A set of these smart pixels could make up a matrix, which may serve as a detector. This could be used in place of the numerous sensors used for detecting infrared rays in existing heat cameras. The researchers hope to add in more developments so that even a device as small as a mobile phone can include a heat camera. Since the materials needed for fabrication are non-toxic, inexpensive, and easily available, the feature could be had at a low cost.

Sunlight Charged Supercapacitor

The researchers built the heat-powered transistor by exploring a technique that allowed charging a supercapacitor by sunlight. The capacitor, developed a year ago, captures the light photons falling on it to convert to electricity, which is stored within it for further use. Crispin explains that it was crucial to establish the working of the heat driven supercapacitor before looking into possible electrolytes and the range of possibilities.

The university team researchers looked through a wide range of conducting polymers to turn out a liquid electrolyte that can produce a potential difference from a temperature gradient a hundred times more than that most electrolytes generate. While the positive ions of the electrolyte are small and move quickly through the liquid, the polymer molecules are negatively charged and massive, and move slowly. When a part of the electrolyte is heated, the lighter positive ions move to the colder regions rapidly. The separation of the positive ions from the negatively charged polymer molecules generates a potential difference or a voltage, which is adequate for transistor applications.

Team members Simone Fabiano, a lecturer, and Dan Zhao, a researcher engineer, have worked extensively with the electrolyte to show that heat signals can be used to make electronics controlled by heat signals.

Metamaterial Cools Buildings without Using Energy

Engineers at the University of Colorado Boulder have built a metamaterial that can be used to cool structures without drawing on any energy. The material can also cool objects placed in direct sunlight without using water.

A metamaterial is an artificial substance with remarkable properties not possessed by natural substances.

According to Xiabo Yin, an assistant professor at Colorado Boulder and a director of the research, the new metamaterial could be a game changer in the field of radiative cooling technology. Since the technology does not make use of water and electricity, it presents a huge opportunity in the fields of power generation, agriculture, space research, and several other areas.

The metamaterial, which could make for an environmentally friendly and cost-effective technique for cooling homes and industrial applications, has been discussed in the journal Science. Thermoelectric power installations, which need a large amount of water for maintaining the low temperatures of the cold junction could instead make use of this material for cooling purposes. The hybrid material can be fabricated in the form of glass-polymer sheets in thickness of 50 micrometers. It is only marginally thicker than the kitchen aluminum foil and can be manufactured on rolls, making it economically viable for large-scale production.

When placed over an object, the film cools the surface beneath it by reflecting the incident solar energy radiations back. At the same time, the film helps the object lose the heat contained by emitting low frequency infrared radiations. Field demonstrations were conducted at Cave Creek in Arizona and Boulder in Colorado. The tests showed that at both places, the metamaterial had an average radiative cooling power of 110 W/square meters for 72 hours at a stretch. During direct sunlight at noon, the radiative power recorded was 90 W/square meters.

Gang Tan, an associate professor in the Department of Architectural and Civil Engineering of Wyoming University, explains the test results imply that about 20 square meters of the material installed on the roof of a single family home could achieve reasonably good cooling in summer.

Apart from cooling buildings and power plants, the new polymer-glass hybrid material can serve to enhance the efficiency and life of solar panels put up for electricity generation. Intense sunlight tends to damage solar panels. Yin explains that a layer of the material applied to a panel can boost the efficiency by almost 2%.

The cooling power of the material is approximately equal to the electricity produced by a solar panel of the same area. However, while solar cells can operate only during the hours of sunshine, the new material provides radiative cooling at all hours.

The researchers are now waiting for a patent for the new material and the technology. They are also working with the Technology Transfer Office at CU Boulder to look at prospective commercial applications. A potential project in the offing involves the creation of a model cooling-farm in Boulder sometime this year.

The team has been awarded a grant of $3 million for the invention of the metamaterial and the related research projects by the Advanced Research Projects Energy Agency connected with the DOE.

PiFM: A Pirate Radio with the Raspberry Pi

The popular single board computer, the Raspberry Pi (RBPi), can work as a radio transmitter as well. Using a simple hack, you can turn your RBPi into a powerful FM transmitter with adequate range to cover a bike parade, high school ball game, silent disco, DIY drive-in movie, or even your entire home. However, the broadcast frequency covered by the RBPi is rather large—one to 250 MHz, and there is a possibility this will interfere with government bands. Therefore, it is advisable to limit the transmissions to the standard FM band of 87.5 to 107.9 MHz.

You do not need much to make the RBPi start transmitting. The RBPi board itself, a power source, and the SD card with the OS is all that is necessary. The only accessory required is a piece of wire, which acts as the antenna. The entire project runs on the software PiFM.

Oscar Weigl and Oliver Matios developed PiFM originally, and Ryan Grassel revised it. This project uses the PirateRadio.py script, which enables playback without accessing the command line, while handling most common music file formats automatically. Wynter Woods, a MAKE labs engineering intern, wrote the script.

Oscar and Oliver had hacked the original PiFM code over a few hours. To output FM radio energy, their code used the hardware on the RBPi that actually generates spread-spectrum clock signals on the GPIO pins. Therefore, to turn the RBPi into a really powerful FM transmitter, all that was necessary was to add a wire length acting like an antenna to one of the GPIO pins. The original code used the GPIO pin 4 with a wire of length about 20 cm attached to it. For transmission, Oscar and Oliver had chosen the frequency of 100.0 MHz.

When Sam Freeman and Wynter Woods tested the present project, they found the FM signal only deteriorated once it had to pass through several conference rooms with heavy walls. The signal was able to cover 50 m easily, and objects such as heavy metal cabinets could stop it. They found the sound quality acceptable, although it has some clicks that came from the CPU switching to tasks other than playing music. For the technically minded, a kernel mode driver uses the DMA controller for preventing the RBPi CPU from being loaded, and thereby plays smooth music.

The Python script calls a C program that maps the peripheral bus of the physical memory into virtual address space. After this, it enables the clock generator module and sets points its output to GPIO4. Note that you will not be able to use any other GPIO pin at this time. It also sets the frequency of transmission to 100.0 MHz, which acts as the carrier. If you receive this on a radio, the radio will stop the background noise and become silent.

The carrier is modulated by the audio produced by adjusting the frequency using the fractional divider between 100.025 and 99.075 MHz. The fractional divider can produce audio with only 6-bit resolution. As the RBPi is very fast, it can use 128 subsamples on every real audio sample to produce 9.5-bit audio. The subsample algorithm now gives full 16-bit quality sound with FM pre-emphasis.