Saturday, February 18, 2012

TI's new development kit helps engineers quickly and easily design Bluetooth® technology-enabled applications based on Stellaris® microcontrollers

Texas Instruments Incorporated (TI) (NYSE: TXN) today announced the Stellaris® 2.4 GHz CC2560 Bluetooth® Wireless Kit (DK-EM2-2560B), aimed at jumpstarting Bluetooth®-enabled designs. The kit includes the high-throughput, power-efficient CC2560 Bluetooth solution and proven Bluetooth stack within StellarisWare® software. The performance and integration of Stellaris MCUs pair with TI´s leading Bluetooth solution to help developers address the demand for more streaming audio, remote control and data transfer in industrial and consumer applications. For complete details, visit For a video demonstration, visit

With this offering, TI further expands its broad portfolio of complete microcontroller and wireless technology solutions, which includes 16- and 32-bit MCUs backed by ZigBee®, low-power wireless, RFID, and Bluetooth hardware and software. The Stellaris 2.4 GHz CC2560 Bluetooth Wireless Kit is modular and can be combined with the same Stellaris DK-LM3S9B96 Development Kit that serves as a baseboard for other Stellaris wireless solutions. When coupled with the DK- LM3S9B96 development board, the kit includes all hardware and software needed to jumpstart development. It also speeds the design process, as engineers are able to evaluate the working Bluetooth solution within 10 minutes or less using the included quick-start application.

What’s included in the Stellaris 2.4 GHz CC2560 Bluetooth Wireless Kit
·         StellarisWare® software, including peripheral driver library and example source code
·         Bluetopia® Bluetooth stack – developed by Stonestreet One and licensed, delivered and supported by TI – which includes the Serial Port Profile (SPP), Advanced Audio Distribution Profile (A2DP) and Audio Video Remote Control Profile (AVRCP) with sample applications

·         Stellaris DK-LM3S9B96-EM2 Expansion Board
·         PAN1323 Bluetooth v2.1 + Enhanced Data Rate (EDR) Module
·         TI eZ430 USB emulator with Bluetooth target board and plastic cover
·         Battery board
·         Two AAA batteries
·         Earbud headphones
·         StellarisWare® CD

Features and benefits of the Stellaris 2.4 GHz CC2560 Bluetooth Wireless Kit
Bluetooth 2.1 technology + EDR support
Best-in-class Bluetooth RF performance for robust, high-throughput wireless connection, extended range and better power efficiency
Complete, validated, certified, production-ready module (PAN1323 used for evaluation, PAN1315 or PAN1325 used for production)
Lower manufacturing and operating costs, save board space, ease certification, minimize RF expertise required
Sample applications for the Stellaris LM3S9000 series, with demos showing API usage provided in source code
Simplifies and reduces hardware and software development, allowing faster time-to-market

Price and availability
The Stellaris 2.4 GHz CC2560 Bluetooth Wireless Kit (DK-EM2-2560B) is priced at $199 US, and available to order today at The DK-LM3S9B96 is sold separately for $425 U.S., and available to order today at

Monday, February 13, 2012

Fundamentals Of Low-Power Design

In the realm of design, the quest for low power continues ad infinitum as a primary goal. Yet low-power requirements place significant additional constraints on designs, constraints that ordinarily would be secondary or non-existent. Often, a simple oversight in the firmware executing on a part can substantially reduce battery life.

When on this quest, designers must ask—before writing any code, selecting components, or creating schematics—what “low power” means. Almost always, the answer is that it depends. For instance, it depends on the application, the typical use case, and a whole slew of tradeoffs involving cost, performance, size, and other factors.

Classifying Devices With Regards To Power
Classes of devices with vastly different power needs and power consumption profiles typically include:

• Rechargeable, battery-operated handheld devices: These devices, which often have a runtime measured in hours, are designed to be frequently recharged. They perform little or no processing when off, but significant processing when running. Portable media players and cellular phones fall into this category.

• Devices that spend most of their time in sleep/standby: Such devices have runtimes measured in weeks or months. There’s very little processing when the device is on, and it returns to sleep mode quickly. Most of the time, the device is in deep sleep or standby. These devices include IR/RF remote controls, portable test equipment, wireless keyboards, and blood-glucose meters.

• Devices that are barely alive: Runtimes for these devices are measured in months or years. Minutes, hours, or even days can elapse between short bursts of activity. They’re often found in remote monitoring applications. Utility metering and data loggers are two examples.

Means Of Measurement
So, how do you identify a low-power device? Once again, it depends. There are many ways to define and measure power consumption. Any datasheet, product brief, or application note for a low-power microcontroller comes replete with a colorful assortment of specifications. Common specs include MIPS/watt, mA/MHz, low-power run-mode current consumption, and sleep-mode current consumption.

No single specification tells the whole story, and the actual performance depends heavily on the use case. For instance, a device with a great mA/MHz specification might have an unacceptable sleep-mode current. What’s more, the functionality in each of these sleep modes may not even be easy to quantify. Does the part have any timers active in the mode of interest? Does it keep the contents of RAM? Comparing apples to apples here is an effort unto itself.

Power-Saving Techniques
Despite the myriad product specifications, requirements, and design constraints, much can still be done in any design to minimize power consumption. The following standard techniques can help save power on most modern microcontrollers and processors:

Eliminating Parasitic Peripherals
Since many microcontrollers come out of reset with peripherals enabled, disabling unused peripherals will save a significant amount of power. Often, this is simply a matter of clock gating; turning off the clock to a peripheral will completely eliminate its power consumption. In some situations, though, a more sinister power sink lurks in the bowels of peripherals, a.k.a., quiescent current.

In applications that demand deep sleep and maximize every nanoampere, the peripherals’ quiescent-current consumption becomes vital. Analog peripherals such as comparators and analog-to-digital converters (ADCs) are good examples where clock gating alone won’t suffice when powering down the peripheral.
1. This excerpt from Freescale’s MC9S08QE32 datasheet for the analog comparator peripheral illustrates how leaving the comparator on isn’t a good idea.
The specs shown in Figure 1 were lifted from datasheets for Freescale’s Flexis QE series low-power microcontrollers. On the Flexis QE32, the comparator’s power consumption falls in the 20- to 30-µA range. This may not seem like a lot, but considering that the deepest power-down current consumption on the device measures 350 nA (at VDD = 3 V), leaving that comparator on isn’t a viable option.
Configuring Unused I/O
Unused I/O can be a major source of unwanted power consumption if it’s left configured as an input. In standard CMOS logic, power consumption occurs only when switching states from on to off and vice versa. Floating inputs will cause unintentional switching. The best way to handle unused I/O is to set it as an output when power must be saved, i.e., in a power-down or low-power run mode.
From a board-level perspective, it’s important to consider the lowest power state of the circuit connected to the pin. For example, if the pin is pulled up or down externally, set the output to the value corresponding to VDD or ground, respectively.
Remember, in this scenario unused I/O isn’t limited to the I/O that’s never used. Any time a peripheral or a set of I/O isn’t necessary, it can be reconfigured as an output on-the-fly. This is generally a good idea when entering a low-power mode of operation that works with limited functionality. Dedicated analog inputs must be treated carefully at the board level, as they can be input-only pins with input impedances in the tens of kilohms.
Run-Mode Clock Throttling
In applications featuring a device operating in active mode, where the CPU is enabled and processing for extended periods of time, it makes sense to carefully evaluate the performance/power tradeoff. For instance, low-power applications rarely require blazing-fast speed. Usually, the CPU performs some rudimentary calculations on data or manages peripheral interaction with the outside world.

2. This excerpt from Texas Instruments’ MSP430F2132 datasheet lists the run-mode current for various CPU clock frequencies.
At times, the CPU needs to be on, but its role is limited. Here, lots of power can be saved by throttling its clock down to a level where it efficiently processes data without becoming idle. An excerpt from the Texas Instruments MSP430F2132 microcontroller datasheet illustrates this point, listing the active-mode current consumption at various CPU clock frequencies (Fig. 2).
Taking Advantage of Bursty Operation
On the other side of the CPU throttling coin, bursty operation for processing and data acquisition offers another good opportunity to save power. The principle behind this technique involves minimizing the time in an active mode of operation. It may be unintuitive, but performing the tasks that consume lots of static current for a shorter period of time can be more power-efficient than doing so for a longer period of time at lower power. This applies equally well to CPU run modes and high-power peripherals such as ADCs.

3. Shown is the active-mode current consumption versus processing time for two hypothetical microcontrollers: an eight-bit CPU (a) and a 32-bit device (b).
The burst-mode principle for processing data can be elucidated further by comparing power consumption between 8-bit and 32-bit hypothetical devices (Fig. 3). Both wake up with the same periodicity to acquire and process data. Because the 32-bit device (right) can complete the processing task faster, it’s out of its high-power mode quicker when the sleep interval and data-to-process remains constant. Also, note the difference in the baseline power consumption, with the 8-bit device having the lower of the two. The area under the curve represents total energy consumption. Therefore, the lower-power run-mode on the 8-bit device (left) isn’t necessarily an advantage.
Data-acquisition tasks from peripherals follow this principle, too. Turning on an ADC for short periods of time, only when needed, minimizes the time it’s actively consuming current. Interleaving the data acquisition and the processing tasks will result in more efficient power usage.
Low-power, low-frequency clock sources can be employed to manage sleep/wakeup cycles. Such a timer comes standard on most modern microcontrollers. If not available, then highly accurate and low-power 32.768-kHz watch crystals are an ideal substitute.

Hardware and software design for low power is application-specific. The key part of the process is to become intimately familiar with your product and its intended use case(s) before making any major design decisions.
Most of the design process depends on factors that change with each project. However, following some basic strategies, such as using power only when needed, managing parasitic peripherals, and being careful about clocking, can effectively minimize power consumption.

Engineer from Cornell University: sudoglove

Friday, February 10, 2012

Siemens and BMW believe in Wireless EV charging station

Electric cars (EV) now fall in short-term production plans of most of the car manufacturers. It is a news of these days, in fact, the market expected at the end of the year (at an estimated price of less than 7000 euros) of the Renault Twizy, a zero-emissions two-seater equipped with a 20 hp electric motor, battery life of around 100 km, and charging time of approximately 3 hours and a half. Just charging seems to be one of the troubles of these new-generation cars, ecological, yes, but forcing the user to adopt new habits with regard to refueling operations.
Some European countries (one of these is the Netherlands) have already endorsed projects to create ad hoc service stations specifically equipped to perform the rapid charging of the next coming electric cars. The evolution is however still at an early stage, so the only valid alternative, for now, is to have a garage or parking space with electrical outlet to be able to recharge batteries when the vehicle is not used and by using the appropriate electrical wiring (the equivalent of the "gun" in the traditional gas station). Actually, there is already today a technology that can fully address this problem, a technology that harnesses the wireless power transmission to charge the batteries without requiring ing any electrical connections.

The first practical applications of this technology have been achieved by HaloIPT, a company founded as a spin-out of Auckland University. HaloIPT was the first company in the world capable of marketable wireless charging systems for electric vehicles. These systems are based on the IPT (Inductive Power Transfer) technique, that exploits the physical mechanism of electromagnetic induction to transfer (or rather, to induce) a power supply at a short distance. At the recent Hannover Fair (now the largest industrial trade fair in the world), Siemens and BMW presented their own system for wireless recharging of electric vehicles, based on the same principle, namely electromagnetic induction.
If this technology will take hold, future electric cars will no longer need cumbersome and annoying cables for charging. Contactless technology also provides another significant advantage: the charging stations will be able to be installed almost anywhere (the housing is made under the soil), effectively making them almost invisible and protected from vandals and wear. The project was funded by the Ministry of the Environment of Germany, and a first test has been scheduled for next June 2011 in Berlin, with the use of different types of vehicles. The inductive charging system developed by Siemens allows charging even for short stops, making the charging process less costly in terms of duration. An example is provided by cabs, used to stand for long periods in the special lanes reserved for them: these stops could be used to carry out a battery recharging operation in a transparent way, working in "background".

The system consists of a primary coil placed completely below the ground, connecting the contactless charging station with the power supply (mains). The electric current through the coil creates nearby an electromagnetic field, which generates, by induction, a current in the secondary coil, placed at a distance of 8-15 cm from the primary coil and installed aboard the electric or hybrid car. The secondary coil, in turn, allows thus to recharge the battery. The theoretical efficiency of this system was estimated to be at least 90%, but we must wait until next May, when a 3.6-kW prototype will be thoroughly tested. The system is designed and installed so that the electromagnetic field generated interest only to a well determined area between the two coils. By law, it must meet international standards, which recommend an upper limit for the generated electromagnetic field equal to 6.25 microtesla. Siemens has ensured that the intensity of the electromagnetic field generated by their system meets this requirement, so there is no risk to health. In addition, the charging stations will be able to use the surplus energy produced by solar panels or wind systems, thus minimizing the impact on the environment.

The system designed by Siemens in cooperation with BMW will be tested and verified in practice over the coming months so that designers will be able to do the required changes and improvements to it. We should also recall that BMW strongly believes in the future of electric vehicles (EVs) and hybrid cars. With respect to this topic, they recently announced the creation of a new brand of models (identified by the letter "i") with the aim to offer the most advanced solutions for future mobility. In 2013 it is expected the launch of the models BMW i3 (a compact city car, also called as "Megacity"), and BMW i8 (a sportcar with a winning design). The BMW i3, visible in the drawing below, will be equipped with an electric motor with rated power of 100kW and aims to have minimal impact on the environment, with extensive use of carbon fiber materials to reduce weight and increase the rigidity of the vehicle.

Monday, February 6, 2012

Corning's A Day Made of Glass 2 gives us a window into the future

Before Microsoft bamboozled us with its vision of the future, Gorilla Glass maker Corning blew our socks off with its A Day Made of Glass video.

The YouTube phenomenon (17 million views and counting) gave us a glimpse of the world of tomorrow and was so attractive because it all seemed so possible, as many of the technologies on show have already been developed and are just waiting to hit our homes and streets.
And now we've had to spend another 5 or so minutes with our jaw on the floor as A Day Made of Glass 2 has been released.

According to its makers, the sequel "extends the ideas, applications, and interfaces introduced in the original video into new arenas – including healthcare and education – continuing the story of how highly engineered glass, with companion technologies, will help shape our world".
According to us, it's just bloomin' brilliant. How can you not love a bit of AR Jurassic Park action, or the fact that a doctor can literally drag a patient's brain around?

There's also an extended version of the video that gives a bit of extra detail on the technologies used in the action.


Sunday, February 5, 2012

Does the World Need a New Microcontroller Family?

Everywhere you look there are microcontrollers. 8-bit, 16-bit and 32-bit; high speed or low power; single or multi-core; and an enormous range of peripherals and I/O. So does the world need another family?  Infineon certainly thinks so.
Their reasoning runs like this. Over the last few years the company has been restructured to concentrate on three key areas, which it calls Energy Efficiency, Mobility and Security. In these areas it addresses specific markets, where it is either the largest player, or number two, with microcontrollers, power components and sensors.
The current microcontroller line-up is headed by the TriCore family. (This has 28% of the 32-bit automotive embedded market, and the claim is that almost every second car has a TriCore. It is also widely used in industrial applications.) Backing this are multiple families of 16-bit microcontrollers, designed around the proprietary C166 core, and 8051-compatible 8-bit controllers. There is a significant performance gap between the fastest members of the 16-bit families and the slowest of the TriCores, and this gap is what Infineon is now bridging with its latest announcement.
The intention is to provide a microcontroller that will find applications in controlling industrial drives, in renewable energy and in industrial automation. This requires high computer performance, mixed signal capacity, connectivity, both within and outside the system, and, usually, complex software. Infineon claims that the XMC4000 meets all these needs, and more.
The first surprise is that, after decades of developing its own processor architectures, the new family is based on the ARM Cortex-M4. While ARM is very widespread in microcontrollers, this is a definite change. Infineon people would not be drawn in to give too much detail about future plans, but they did say that the TriCore will continue, as it is particularly well suited for safety-critical applications. They gave the impression that they haven’t ruled out further ARM-based microcontrollers, and the implication was that these would be replacing/supplementing/whatever the 16-bit products.
The public reason for choosing ARM is the massive ecosystem that is available for ARM products. And, speculating, a secondary reason must be that paying ARM is a lot cheaper, and easier, than developing a new architecture.
Around the core is a wide selection of peripherals. Some are standards-based, such as Ethernet and USB; some are Infineon implementations of general functions, such as ADC and DAC, memory interfaces and CAN bus; and there are also “Infineon state-of-the-art” implementations, such as capacitive touch controllers, a real time clock, and memories. The road map shows a fairly typical matrix of clock speed, memory - both flash and SRAM, and packaging options. Unusually the clock speed is measured at 125ºC, rather than the lower temperatures normal for industrial parts. This is because, in applications like motor control, the microcontroller will be mounted directly on the motor, where temperatures can run very high.
A particular example that was discussed in the launch presentation was inverter control in applications like electric drives and photovoltaic connections to the grid. In both cases the inverter takes in DC and outputs AC. The XMC4000 family typically has 4 fast (3.5 million samples/sec) 12-­bit ADC modules and a ΔΣ demodulator. This allows processing to be carried out off the CPU and removes the need for an extra interface IC. A connection matrix can be set up in software to create direct connections between peripherals.
One unusual feature is the provision of up to six serial channels, whose function, (UART, SPI, I2C etc) is defined in software.
These two examples bring us neatly to the development environment. The XMC4000 is supported by the third generation of DAVE (Digital Application virtual Engineer), Infineon’s free IDE. DAVE is Eclipse-based (so it interworks with a wide range of other development tools) and comes with a free GNU compiler, a debugger, and a loader. The new version also includes a selection of apps for peripherals and applications, which are configured through a graphical user interface. When the apps are configured, DAVE generates code that can be used like a library through an API. Infineon expects that third parties and users will generate further apps.
There were simultaneous announcements from tools and middleware companies, with Atollic, IAR and Hitex all announcing support. And a slide in the presentation also named Altium, Wind River, Keil, iSystem, Lauterbach, Express Logic, Micrium and Segger as supporting the family. While most of these support the existing Infineon parts, the Cortex core makes it far easier for them to create XMC4000 specific products.
I have made a bit of a meal out of this announcement, as it can be seen as important for a number of reasons. Firstly it is another example of the way in which, despite several commentators’ views, ARM is still strengthening its hold in the microcontroller market. There are other cores around, often for niche markets, but ARM is still growing in the main stream. It also seems to me to be yet another blow for 16-bit controllers – their future is going to be even more limited as 8-bits continue to mop up low power and simple applications and 32-bit controllers offer more processing power at equivalent, or better, electrical power consumption. And finally it is an example of how the peripheral options are increasingly complex, moving from external chips to the controller core.