Word on the street has it that soft drink bottlers may soon use embedded chips in vending machines to raise the price of soda during heat spells.
Sound far-fetched? It may not be a good marketing strategy, but technology is available to make the idea a reality.
In fact, some vending machines today incorporate chip and software combinations to track inventory and manage money. Add Internet connectivity, something soft drink giant Coke promises to offer so that consumers can have an interactive experience when they buy a soda, and all you need are temperature sensors to make it happen.
All of this is made possible thanks to embedded systems, which are helping the white goods, consumer products, and retail and manufacturing industries go high tech.
More than 38 million embedded devices are used worldwide in cars, cell phones, digital cameras, dishwashers, refrigerators, telecom and data communications, and industrial controls. The market for embedded systems is expected to grow at an average of 13% a year over the next five years, rising from $32 billion in 1998 to nearly $67 billion in 2004, says John Ross, a consultant with Business Communications Company.
Embedded systems are computers hidden inside products we use every day. They include embedded software, embedded processors (meaning microcontrollers, microprocessors, and digital signal processor segments); embedded memory (random access memory (RAM) and programmable read-only memory (PROM), as well as Flash memory (reprogrammable), and embedded boards. All embedded systems can accept programming.
"Embedded devices are like a desktop computer, but without the traditional interfaces, such as a mouse or a monitor," describes Jim Balent, product line manager with National Instruments (Austin, TX). Deep behind the scenes, they can power everything from anti-lock brakes and airbags in cars to pacemakers in the human body.
One reason for the phenomenal double-digit growth of embedded systems is that microprocessor performance is increasing and costs are at an all-time low. But, there are other reasons too:
Applications are demanding greater functionality and complexity than purely electro-mechanical systems can provide.
Embedded systems have made machines less expensive to develop and manufacture.
They also improve product reliability and give longer operating life.
Reaching for an off-the-shelf embedded system and custom programming helps reduce time to market.
Design engineers used to have to learn a unique set of development tools. Now more mainstream software packages are making applications easier to develop.
For an example of how an embedded device can meet these applications, let's go back to the soft drink vending machine example.
|Replacing a mechanical thermostat with an electronic version allows richer features and greater accuracy.|
The beverage industry uses National Instrument's PC/104 interface boards or similar embedded systems in vending machines to scan and accept dollar bills, determine if they are legitimate or counterfeit, a $1 or a $5, and to measure inside temperature to raise or lower it. "Stack PC/104 modules on top of it along with serial ports for communications and data acquisition boards and you can add and share intelligence in virtually any product," says Balent.
But, embedded technology is not only for sophisticated applications, it could also be used for something as simple as a flow valve, so that it has the intelligence to respond to certain conditions and broadcast information to other devices, says Balent.
Traditionally, embedded systems have been difficult to program, but the lines between embedded and PC software technology have started to blur, as software is available that crosses different hardware platforms.
National Instruments produces data acquisition boards for manufacturing and system integration use. These data acquisition boards feature embedded systems with VXI, VME, and compact PCI. Embedded controllers, data acquisition cards, discrete control cards, and motion control cards plug into a bus with timing and triggering lines, enabling data acquisition devices to pass information to each other at high rates of speed.
Embedded software has been notoriously proprietary and closed, in that only certain software worked with certain hardware, and only certain data acquisition boards worked with certain vendors. There were few standards and system support was expensive.
One of the trends, notes Balent, is to move to more off-the-shelf, mainstream PC technologies, like Compact PCI. The bonus, he says, is increased speed.
National Instrument's LabVIEW RT real-time software, for example, runs on a normal computer desktop, but with a simple menu change it can interface with embedded systems on intelligent data acquisition boards. The company's data acquisition, instrumentation control, and image acquisition boards are compatible with Windows NT and the Win32 application programming interface.
"Hardware is just a place to run code," says Balent. "The reason why Java is so hot is that it can be developed once and run anywhere--in any environment." Now, if you can program in Windows, he says, you can specify intelligence in your device. Balent cautions, however, that Windows does not have the power of other real-time operating systems.
"In the past, if you needed a real-time system to perform a brake test in a car, for example, an outside expert would build up a real-time tester for you and you were stuck with it because you did not have the skills to do this yourself," says Balent. "With technologies such as Windows CE, users who can develop desktop applications can apply their knowledge to high-end embedded systems."
Cell phones are big embedded system users. With new cell phone/palm pilot combinations emerging and wireless technology enabling communication between different digital devices, cell phone users can interrupt web surfing to print a page by just passing a nearby printer. On the factory floor, a palm pilot cell phone device could be used in the same way to measure values and send that information to a local database.
In consumer electronics and appliances, refrigerators and washing machines are moving into sophisticated embedded controls. Finbarr Moynihan, systems engineering manager in the embedded control systems group, says that Analog Devices' (Norwood, MA) focus is in supplying powerful digital signal processors for motor control, especially in appliances, industrial applications, and factory automation and robotics. The products integrate a standard DSP core in a variety of peripheral components, such as analog-to-digital conversion and serial ports, which interface with motors. Products include ADNC-401 for high accuracy and fast digital-to-analog conversion required in wafer handling applications. The push at Analog is to provide all the peripheral components needed in high-end applications on a single piece of silicon, in order to reduce size and increase accuracy. "The move is to systems-on-a-chip with faster computing time for more accurate motion and better machine efficiency," says Moynihan.
At Analog's low end is a family of 28-pin ADNC-328 and S-328 DSP devices designed for easy system integration. "There is a revolution going on in appliances," says Moynihan. "White good manufacturers are moving from traditional single-phase, fixed-speed applications to variable-speed compressors, using more sophisticated motors that require more sophisticated control systems." The 28-pin unit provides the full power of the DSP engine, providing the opportunity for more accurate temperature control and even sensorless motor control. "The 28-pin opens up a lot of consumer applications for us," says Moynihan. Those applications include washing machines, air conditioning systems, automotive, and uninterruptible power supplies in office automation. "The advantage of the DSP is that it is more intuitive as an engine and offers a higher programming language." The company offers application kits and web-based example application code to help the integrator.
|A new 12-bit A/D converter on a Microchip 8-bit microcontroller simplifies design and improves reliability. This diagram shows the MCU interfaced to a pressure sensor.|
"Dishwashers are the best example of adding extra features with electronics," says Mitch Corbett, manager of controls engineering with Maytag. Delayed start, automatic detection of soil level and adjustment of the wash cycle are examples of these functions. But cost is a concern, cautions Corbett. "It is still cheaper to use an electromechanical timer over an embedded system, unless that system requires motor controls, automatic temperature controls or other functions." Microprocessors are coming down in price, says Corbett, but you still have to add relays to drive the load, valves, reversing relays, motors, displays, and input/output keys, which up cost to unacceptable levels.
But embedded systems bring added functionality, such as the ability to read sensors and reprogram in the field. And white goods manufacturers find the idea of reprogrammability in the field attractive, says Corbett. Maytag's Neptune washing machine features electronic cycle controls with a timer interface for user feedback. Electronics are also used to control the unit's variable-speed motor control. Corbett feels electronics will eventually replace timers, because consumers want more functionality from machines than timers can supply.
Corbett recommends these tips for the first-time mechanical engineer integrating microcontrollers: Be careful your power supply is designed properly, make certain you have clean power and protection from surges. Check into relay life and reliability, and check out failure modes of electronic components.
For Don Schneider, Business Development manager for the microcontroller group of Toshiba, reliability and cost are driving the replacement of mechanical timers with processors. "In the last two years, we have seen tremendous decreases in price8-bit microprocessors for under a dollar and 50-cent 4-bits," says Schneider. Toshiba sees 4-bits in use in extremely cost sensitive and low performance applications, such as appliances with simple controls and display functions.
If an engineer is looking at a simple, one-time replacement of a mechanical system, a 4-bit is not a bad solution, says Schneider, but if multiple product derivatives are planned requiring different power levels, an 8-bit will provide this design freedom. "The 8-bit offers high-level languages for code reusability and better tools," says Schneider. "In either case, the switch away from mechanical will result in increased reliability and user friendliness."
Toshiba's 870/C family is growing with the recent introduction of two new low-power, high-performance 8-bits: the TMP86CM41F, with 32 Kbytes of on-board Mask ROM; and the Flash version of this part, the TMP86FS41F, with 60 Kbytes of on-board Flash memory. Both are designed around Toshiba's new TLCS-870/C core, with improved C-compiler efficiency at lower cost. "These new devices allow for a highly integrated design solution," says Schneider. The 8-bit MCUs are used in cameras, home appliances, consumer electronics, handheld electronics, and other applications requiring low voltage and low power consumption.
Brains for the brainy
Phoenix-based Microchip has just introduced a family of four new 12-bit analog-to-digital microcontrollers in a 20-pin package. "We are migrating highly sophisticated analog technology into smaller package sizes," says Eric Sells. "Until the MCP320X product, you couldn't find a 12-bit analog-to-digital converter in a 20-pin package--only 28-pin or higher."
The product may be unique, as Sells says, but it points to a growing trend toward design of greater functionality in smaller package sizes, allowing engineers to replace many once-mechanical applications with microcontrollers. The device is ideal for space-constrained applications, smart sensor systems, and processor controls, where data acquisition is important to the design, says Sells.
"Consumers want more features for less money at a higher level of quality, which is driving the replacement of mechanical systems with electronics," says Sells. "But that first step away from the electromechanical into an electronic environment is a scary one for a lot of companies," he says.
In fact, when Microchip introduced its PIC12C line of 8-pin devices 3 years ago, the company created a Mechatronics PowerPak tool kit with a handbook to help mechanical engineers understand design circuitry. The kit provides reference materials, tools, and a tutorial to help the mechanical engineer design intelligence into a system. The company has found that these 8-pin devices are the fastest growing, most popular line it has introduced, because, it claims, mechanical engineers have found them easy to design with. The 8-pin PICXXX devices were designed for electromechanical switch and timer replacement, sensor interfaces, and infrared applications, with a focus on appliances. Since then Microchip created eight devices, offering different memory sizes and peripherals, at a cost of less than $1.50. The chips, available in ROM-based, OTP (one-time programmable) and soon in Flash (reprogrammable) forms, are used in everything from power drills to cell phones.
One of the ways the switch to microcontrollers can boost time to market, says Microchip's Sells, is that a manufacturer can store a certain amount of inventory and do the final programming right before it gets orders, basing that programming on the features that are in demand in different parts of the world.
David Brobst, partner with Solutions Cubed, a Chico, CA embedded design firm, replaced a mechanical timer in a lawn sprinkler system with a Microchip 8-pin microcontroller. "Microcontrollers open up a whole new way of looking at things," says Brobst.
Brobst cites increased reliability as the big advantage of making the switch from a purely electromechanical design to an embedded system. "Electronics are getting so cheap and the mean time between failure is astronomical because nothing moves," says Brobst.
The ability to reprogram or reconfigure the embedded system also makes it ideal. "You can specifically tune it for an application, where as with an electromechanical system it is tough to modify it if something needs to be rethought or added," says Brobst. Other advantages are less heat, and reduced size, cost, and power consumption.
How RFID tracks machine tools
By Christina Lewis
The machine tool industry uses embedded systems such as RFID technology to track tool usage and prevent the wrong tool from being installed into a tool holder.
RFID uses radio waves to transfer information from antennas to tags affixed to the item being tracked. The system consists of three primary components: a tag (also known as a transponder or data carrier, depending on individual manufacturer/user terminology); an antenna (also known as a reader or read/write head); and a controller. Helge Hornis, manager of FA Products for Pepperl + Fuchs (Twinsburg, OH), says the newest generation of identification systems combines the antenna and the controller into one field-mountable unit, commonly called a communicator.
Hornis says RFID is particularly well-suited to machine tool industry identification and tracking applications because of such characteristics as: highly accurate data collection and transfer, even in environments containing grease, dust, paint, and other harsh elements; system flexibility and versatility; the ability to interface with other automation processes; and inherently reliable data transmission.
|In this electromagnetically coupled RFID system, a command is sent from the CNC's controller to an RFID controller, which then processes the command and sends the information requested to the tag, via the antenna. In an RFID system, an antenna serves two functions: powering the tag and reading and writing information to and from the tag.|
Some of the many considerations engineers should keep in mind when designing an RFID system, says Omron's Matt Ream, are:
Make sure the RFID system can interface with the machine center controls. Some systems cannot work with some controls; some can work but they slow down machine process times; some interface seamlessly out of the box; and the vast majority require creative solutions on the part of the design engineer and the controls supplier to develop the most efficient and reliable system for each specific application.
Decide whether you only need basic tool identification (in which case a read-only system is adequate) or whether you need to update information about the tool after each usage (in which case a read/write system would be required).
Determine how much equipment noise surrounds the RFID system. Microwave systems have the highest noise immunity, followed by electromagnetically coupled, low-frequency systems and inductive, low-frequency systems. Some inductive systems can be seriously affected by surrounding noise.
Know the amount of data you need to store and update.
Top Embedded Applications
Anti-lock braking systems
Custom data terminals
Aircraft and spacecraft control systems
Unmanned flight systems
Space station test equipment
Head End Equipment
What embedded systems can do for you
Replace timers, switches, relays, counters.
Boost reliability with fewer moving parts.
Make your product lighter and smaller.
Provide changeable functions.
Lower power requirements.
Increase product features.
Increase design staff productivity.
Cut customer product costs.
Reduce time to market.
Five tips to make the switch
"First take a look at the overall application and the different functions needed to drive it," says John Ross, Business Communications Company consultant. "Then pick the best embedded product--microprocessor, microcontroller, or digital signal processor--to meet the application needs."
Electronics expert Ross offers these tips about switching out an electromechanical system for an embedded one:
Determine the size, power, and cooling requirements of the system and its devices.
Consider the ability to scale or upgrade the embedded product and whether the embedded system allows application interoperability.
Don't skimp on protection circuitry.
Figure out if the microprocessor works with reusable software products.
Embedded devices may not totally eliminate electro mechanical sensors, but instead they may more precisely control relays and timers.