EEWeb Pulse - Volume 32

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Issue 32 February 7, 2012

Jeff Smoot CUI Inc

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TA B L E O F C O N T E N T S TABLE OF CONTENTS

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Jeff Smoot Vice President of Engineering Interview with Jeff Smoot - CUI Inc

8

New Power Topology Propels Quarter-Brick Bus Converter to Benchmark Power Density

BY JEFF SMOOT CUI’s new Solus Power Topology is pioneering a new era in power supply performance.

Featured Products Keep Noise Down When Making Low-Level Measurements

12 14

BY ROBERT GREEN WITH KEITHLEY

Learn how to make successfull low-level measurements and use appropriate techniques to minimize errors.

17

Arduino for Mere M0rtals - Part 1

BY ROBERT BERGER WITH RELIABLE EMBEDDED SYSTEMS

How three Italians formed a rather unconventional approach to electronic prototyping software.

RTZ - Return to Zero Comic

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INTERVIEW

CUI Inc Jeff Smoot - Vice President of Engineering

How did you get into electronics/engineering and when did you start?

I kind of got into electronics by accident. I went to Montana State University and got a B.S. in mechanical engineering, so I started my career as a mechanical engineer.

Growing up, I went to what I like to call Engineering Nerd Camp during high school. It involved going to the University of Wyoming where they take you in and expose you to a bunch of different projects and disciplines over the course of about a month. I definitely liked the mechanical side. Any time I touched electrical engineering, whether it was during the camp or during the classes I had to take for my degree, my thoughts were always, “I’m so glad I’m not going to be doing anything with electronics and I’m going to be away from that industry!” When I got done with my circuits class I was like, “Hallelujah!

I can sell my book back for 45 dollars and never use or touch it again.” Lo and behold, five or six years later, after working on the mechanical

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FEATURED INTERVIEW

Jeff Smoot

INTERVIEW

What are some of your favorite hardware and software tools that you use?

Definitely one of my favorite hardware tools, and this is probably due to my mechanical engineering prowess, is the thermal imaging camera. I love using it to take images, because with power supplies and electronics in general, you can have a great product and a great design, but so often it comes down to heat and how you get rid of it.

I’m also a pretty big fan of using the Tektronix oscilloscopes we have here in the lab for looking at the waveforms or the voltage levels.

Can you tell us a little bit about CUI and the products it offers?

We have our core business, which includes our components, which are things like speakers, connectors and buzzers. Supplying components like these 22 years ago is where CUI got its start.

We also have our encoder line consisting of optical encoders and our proprietary AMT encoders which use capacitive technology for rotary encoder applications. It’s based on the same building blocks as what’s in digital calipers. We’ve been able to take that and adapt it into rotary sensing.

And we have our power line, which consists of a broad range of

standard dc-dc converters, openframe ac-dc power supplies, and external power adapters.

One of the main focuses for us with the Novum line—specifically our digital point of loads—is really driving interoperability within digital power systems.

Those three areas are currently our primary business areas, but my team and I have been focusing on our Novum® Advanced Power line. It targets the Intermediate Bus Architecture, and right now the products are primarily dc-to-dc converters from the Intermediate Bus converter all the way down to the point of load. CUI has been one of the first companies out there with a fully digital point-of-load module.

We’ve also been working on some pretty exciting stuff with our Solus™ Power Topology, which is a new switching topology that allows us to get higher efficiency and greater power density for dc-dc conversion.

It’s also very applicable on the ac-dc side.

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What are some of the advantages of using the capacitive encoder technology over a standard optical encoder?

Optical definitely has the lion’s share of the market; it’s the known go-to technology. But some of the difficulties of optical are that you have to be very precise and very careful with how you mount it. If you get a thumb print or something on the code wheel, you’re done. It’s very sensitive to dirty environments, which can lead to improper readings or functioning issues. Optical is also very susceptible to vibration because it usually includes a glass disk.

With capacitive encoders, because we’re not worried about optics, we can ignore the susceptibilities that exist with optical because they are not sensitive to those types of environments. We have one customer who has had a capacitive encoder mounted on a motor submerged in oil, and it’s still working. They can work in a variety of environments that optical can’t.

And with regard to the performance, optical and capacitive encoders are the same. It’s a nice alternative even if there aren’t environmental concerns.

What are the general applications for the Novum technologies you’re working on?

One of the main focuses for us with the Novum line—specifically our digital point of loads—is really driving interoperability within digital power systems. Digital offers the industry a great tool with a

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FEATURED INTERVIEW

engineering and manufacturing engineering side, an opportunity opened up here at CUI which I worked into, and now I do electrical engineering on a daily basis.

INTERVIEW

Another goal is to be able to adjust the entire bus to a particular voltage for the application to perform at its optimal efficiency.

The main issue with addressing these goals is the problem of interoperability. A power system is comprised of many different converters that must all be able to work together. In today’s systems, there is a high likelihood that these converters will be a mixed solution of POL modules and discrete board level designs. In the digital space, this presents a challenge because each controller and module manufacturer have slightly different protocols for the SMBus/I2C and proprietary serial buses. CUI is working to provide customers with digital power implementation options, whether a system requires a mixed discrete/POL module or a full POL module solution.

Do you have development boards or other supplies for embedded solutions?

Yeah, we have development boards of our point-of-load modules and our Solus quarter brick, which we’ve recently announced. It is 445 watts per cubic inch, and an industryleading 720 watts in the quarter brick package.

Can you tell us more about the Solus Power Topology?

It is a SEPIC-fed buck converter.

Essentially what we did was we took a single-ended primary-inductor converter (SEPIC) and combined it with a buck converter for a new technology that provides the best advantages of both converters.

What the topology does by branching both the voltages and currents down multiple paths is it allows us to drastically reduce the switching losses in a buck converter. One of the best aspects that the Solus Topology offers is a 75 percent switching turn-on loss reduction. With that, we can get higher efficiency and higher power density because we’re not running as much voltage or current across any one component. It virtually eliminates the turn-off losses.

Because of some of the unique properties, we’re able to handle transients much faster than the typical Bus converter. Also, because we’ve significantly reduced the switching losses, it opens the door to some higher frequency converters.

The options are almost endless with where we can go with the topology.

Do you have any tricks up your sleeve, such as a special way of analyzing problems?

I wouldn’t say I have any major tricks.

I definitely like to break problems down into the basics or fundamental elements of the particular issue.

on the board and in the design. I’ve found that this will save you a lot of headaches down the road.

Do you have any note-worthy engineering experiences?

I’ve caught multiple things in the lab on fire over the years! But other than that, nothing really note-worthy outside of the fact that I’ve had the pleasure of working side-by-side with a lot of really great engineers here at CUI and it’s been a lot of fun developing the company into a great, industry-leading technology company.

What is the culture like at CUI Inc? While we are a highly-energized company focused on bringing innovative products and business practices to the marketplace, we are also a company that has a great family atmosphere and sense of community. We definitely think that what we have and what we’ve been able to do is a gift and a blessing, and now we’re trying to give back.

We were recently able to take an afternoon and close down the department and go visit a Habitat for Humanity job site to donate our time. CUI does things like that at various times throughout the year, and is our way of giving back to the community. It’s one of the nicest aspects of working here. CUI truly is a company that cares a lot about giving back, and it’s great to be a part of it. ■

One key element that people should keep in mind with regard to power system design, in addition to thermals, is grounding. Pay special attention to how grounding is done

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FEATURED INTERVIEW

range of diagnostics and reporting information that hasn’t been readily accessible. The data that digital power offers would involve things like temperature feedback and current feedback so that someone can look remotely and see that, for example, a board is running hot or running a little bit more current.

They can then schedule someone to perform maintenance.

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The increased drive and speed along with the very high CMR (common mode rejection) and isolation voltage will enable you to build more efficient and reliable motor drive and power conversion systems. In addition the SO6 package which is up to 50% smaller than conventional DIP packages facilitates smaller more compact design.

Benefits • Suitable for wide range of IGBT class for different market applications • High output peak current for fast and efficient IGBT operation • Rail-to-rail output voltage for reliable IGBT operation • Lower system power budget • Suitable for bootstrap power supply operation • Reduce dead time and improve system efficiency • Prevent erroneous driving of IGBT in noisy environment • 40%-50% smaller than DIP package for space and cost savings To request a free evaluation board go to:

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PROJECT

By Jeff Smoot

A New Topology CUI is leveraging their Solus Power Topology™ to pioneer a new era in dc-dc power supply performance.

Solus is an entirely new topology, rich in features that accelerate the performance trend trajectories for the big-four power conversion needs: higher power density, higher efficiency for “greener” systems, faster transient response, and lower EMI. CUI is introducing their NQB2060 Novum® quarter-brick bus converter as a prime example of the benchmark 720 watts output power performance using their Solus Topology.

Solus’ Key Features Very simply, the Solus Topology combines the single-ended primaryinductor converter (SEPIC) with the ubiquitous buck converter to form the SEPIC-fed buck converter1.

This new topology enhances the dc-dc power supply in a number of ways. The ability to reduce power losses is most important in Solus

Topology’s long list of features.

Solus Topology achieves increased efficiency by reducing both the conduction and the switching losses at several critical points within the converter circuit. The loss reduction is so significant that CUI can increase the output current by 40% for a given power supply package size. Conversely, the loss reduction enables increased efficiency by several percent for “green” designs for a given output

current and package size when compared to the traditional buck topology.

Lower Conduction Losses Via Lower Internal Currents Implementing the “divide and conquer” concept, the Solus Topology accomplishes the reduction of conduction losses by channeling the operating currents into several paths. Figure 1 shows the schematic for the Solus

I4=0.55 IOUT

T1A

D

T1C

Q1SB

GCE

C2

Q2S

VIN+VOUT 2 VIN+VOUT 2

I7=0.55 IOUT T1D

D

Q2S S

VIN

D

Q2B

Q1SB VIN+VOUT Q2B

IOUT

S

I1=0.1 IOUT

VDS

I6=0.55 IOUT

S

C1

C3

T1B

I3=0.45 IOUT

VOUT

I5=0.55 IOUT

Figure 1: Solus Topology schematic with relative average internal currents (Note M = output/input voltage ratio).

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FEATURED PROJECT

New Power Topology Propels Quarter-brick Bus Converter to Benchmark Power Density

PROJECT (D) I VDS

FEATURED PROJECT

(VIN)

(D)

(VDS)

ID = IOUT 0

ID

ID

VIN+VOUT

VIN+VOUT

(D)

VDS

VDS

VIN 0.5 (VIN+VOUT) PLOSS

PLOSS

ID

ID = [IOUT/(2-D)]

ID

0.5 (VIN+VOUT) x [IOUT/(2-D)] 0

SB On

SB Off

= 2V

VDS

ID

0

0

PLOSS

PLOSS

Solus On

Synchronous Buck (SB)

x [IOUT/(2-D)]

Solus Off

Solus Topology

™

Figure 2: The high-side switch VDSxID switching power loss comparison of Solus converter vs. standard buck converter.

Topology SEPIC-fed buck converter topology. Q1SB functions as highside switch for both the SEPIC and buck operation. Q2B functions as the lowside switch in buck operation. Q2S functions as part of the SEPIC operation. Note that as soon as the input current enters the converter at I1, the topology immediately branches that current into several paths, with each circuit path carrying lower instantaneous current than the output current, IOUT. This reduces the conduction losses by the square of the current reduction identified in Figure 1.

Thus, the conduction losses are significantly less when compared to standard buck converter losses.

The reduced imposed current through the MOSFETs allows the design to obtain lower losses for a given set of devices.

the possibility that, for a given voltage conversion, the design may use lower voltage MOSFETs and capacitors compared to the standard buck converter. This allows substitution of lower Rds(on) MOSFETs in a given device package size.

Reduced Switching Losses With lower applied currents and voltages, the Solus Topology shrinks the VDSxID overlap curve area by the value of:

The result is better than a 75% high-side MOSFET turn-on loss reduction compared to the traditional buck converter. This is shown in the curves’ leading edges for the standard buck on the left and the Solus converter in Figure 2b.

Lower Voltage Stress

Sub-nanosecond Silicon MOSFET Turn-off

The multi-current paths, characteristic in the Solus converter, also reduce the voltage stress on components by nearly 50%. This opens

Even more impressive is the Solus Topology’s ability to eliminate turnoff switching losses. This topology

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is ideally suited for implementing the gate-charge-extraction (GCE) circuit, which has the ability to turn off the silicon MOSFET channel in less than a nanosecond. Figure 3 shows the Solus turn-off waveforms for the high side switch (HSS). The oscilloscope capture in Figure 3 shows the voltage and current waveforms for HSS turn-off. In Figure 4, the red curve shows the instantaneous power during turnoff, which is approximately 50 watts peak and lasts 6.4 nanoseconds for a total power loss at 200 kHz of a negligible 68 milliwatts.

Figure 5 demonstrates the total high-side transistor switching loss when comparing the Solus converter to the traditional standard buck converter. Observe that, as the voltage step-down ratio “M” moves from 0.100, to 0.250, to 0.660, the Solus losses are improved by 91%, 88%, and 70%, respectively. Thus, the Solus Topology is ideal for wideconversion-ratio POL applications.

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PROJECT

Since the input current to the Solus Topology is almost straight dc current with only slight ripple, you can reduce the input capacitors by 95% in size. This feature reduces the EMI due to input current ripple.

Figure 3: High-Side Switch (HSS) Gate Charge Extraction (GCE) waveforms

Figure 4: GCE power measurement

Opening the Door to Higher Frequency Converters At increased switching frequencies, these improvements become even more compelling. The higher the switching frequency you can produce, the higher the power density, if converter efficiency is held to a reasonable level. If we assume equivalent switching losses for both turn-on and turn-off of the high-side switch in the buck converter, the Solus Topology has the potential

to reduce the switching losses by over 90%. This allows the Solus converter to operate at a higher switching frequency without sacrificing very much efficiency, permitting benchmark power density at very reasonable levels of efficiency.

Other Benefits As described, the Solus Topology accomplishes performance improvements with novel conversion methods, not higher performance

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Product Example – The Novum® Quarterbrick Bus Converter CUI’s Solus Topology is now being deployed in their Novum Advanced Power line of products.

The NQB2060 quarter-brick bus converter is the first product in this series being introduced by CUI. They developed the NQB2060 to complement their Novum Advanced Power point-of-load product offering. However, the Novum Quarter-brick bus converter can readily provide power to any POLs needing 12 Vdc input. The NQB2060 is highly efficient over the entire input voltage range so there is no current derating due to input voltage, with the quarter brick able to supply the full 60 amperes output current even at maximum input voltage.

The NQB2060 product specifications are: Vin range = 36~60 Vdc Vdc Vout = 12 Vdc Iout max = 60 amperes over FULL input voltage Pout = 720 watts Form factor = 58.4 x 36.8 x 12.2 mm (2.3” x 1.45” x 0.48”)

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FEATURED PROJECT

components or sophisticated control. Yet, any improvements these other factors afford will further improve on Solus’ new performance platform.

PROJECT Solus™

Standard Buck

100 90 80 70 60 %

50 40 30 20 10 0.100

0.250

0.660

M (Converter VOUT/VIN Ratio)

Figure 5: Total Switching Loss Comparison: Solus vs. Standard Buck Converter

Power density = 445 W/in3 Efficiency: (Vin = 48 Vdc and Vout = 12 Vdc) @ full load > 95% @ peak η (approx. 60% load) = 96% Over full input voltage range > 95% Available in both 1st generation DOSA (2 output pins) and 2nd generation DOSA (4 output pins) configurations.

What’s Next The Solus Topology can be used both isolated and non-isolated dc-dc power supply designs. It is an excellent topology for nonisolated dc-dc point-of-load (POL) power supplies due to its ability to provide a wider duty cycle “D” for given output to input voltage ratio “M”. This is an especially attractive feature for wide-conversion-ratio POLs.

In the canonical buck converter, the D term, or pulse-width ratio, is equal to the M term or output/ input voltage ratio. For the Solus converter, M = D/(2-D). Translating that to an operational advantage, at any given voltage ratio, the pulse width will be wider than for the standard buck converter. Thus, the 12 V intermediate bus voltage is still attractive for powering chips even down to 0.5 V. The Solus Topology should support continued use of the lower-distributed-current 12 V intermediate bus voltage, rather than yielding prematurely to lower

with

Since the Solus Topology maintains its effectiveness independent of the control method used, it can operate with analog voltage mode control, analog current mode control, and various digital control profiles.

That opens the door for CUI to implement this topology in a wide variety of power supply product platforms. The Solus Topology can also improve the performance of the isolated high-voltage dc-dc section of the ac-dc power supply.

Since it can operate very efficiently over a wide voltage range, you can substantially reduce the amount of the bulk hold-up capacitance, reducing the total cost of the power supply.

In this limited space, we attempted to describe as many of the Solus Topology’s performanceenhancing features as possible.

The brief feature descriptions provide insight into the potential of this new topology. CUI’s first product using the Solus Topology, the Novum NQB2060 quarter-brick bus converter, provides undisputed validation regarding this novel topology’s potential. Expanded topological features and product specifications are available in CUI’s product literature. ■

Figure 6: Novum® Advanced Power Quarter-brick

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FEATURED PROJECT

intermediate bus voltage higher distributed current.

Switching Loss Comparison

F E AT U R E D P R O D U C T S Texas Instruments Incorporated introduced a low-side gate driver for use with MOSFETs and Gallium-Nitride (GaN) power field-effect transistors (FETs) in high-density power converters. The new LM5114 drives GaN FETs and MOSFETs in low-side applications, such as synchronous rectifiers and power factor converters. Together with the LM5113, the industry’s first 100-V half-bridge GaN FET driver announced in 2011, the family provides a complete isolated DC/DC conversion driver solution for high-power GaN FETs and MOSFETs used in high-performance telecom, networking and data center applications. For more information, please click here.

Test Solution for 802.11ac WLAN VNational Instruments announced early access support for testing nextgeneration 802.11ac WLAN chipsets and devices. This announcement exemplifies how NI’s modular, software-defined wireless test platform continually expands to address the latest cellular and wireless connectivity standards including 802.11ac. NI’s 802.11ac WLAN test solution provides flexibility in testing 802.11ac devices in addition to testing 802.11a/b/g/n devices. It works with a wide range of signal bandwidths including 20, 40, 80 and 80+80 160 MHz for both Tx and Rx for up to 4×4 MIMO configurations. For more information, please click here.

Smallest Programmable Clocks Silicon Laboratories Inc., a leader in high-performance, analogintensive, mixed-signal ICs, introduced the industry’s smallest and lowest power customizable clock generators. Available in a tiny 1.7 mm-squared package, Silicon Labs’ new Si512xx clock generator family offers up to 60 percent lower power than competing solutions and is ideal for space-limited, cost-sensitive embedded and consumer electronics such as portable media players (PMPs), industrial metering and monitoring, portable navigation devices (PNDs), handsets, digital cameras and hundreds of other handheld, power-sensitive products. As part of Silicon Labs’ comprehensive, programmable timing portfolio, the Si512xx clocks are highly customizable devices. The Si512xx clock generators support up to three LVCMOS clock outputs from 3 to 200 MHz in a single device, providing developers with maximum flexibility while simplifying supply chain management. Each output has four levels of output strength setting, which can be configured individually to match the load and the trace length condition of the board. This is more than twice the configurability of the closest competing product. For more information, please click here.

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FEATURED PRODUCTS

GaN FET driver ICs

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Robert Green

Senior Market Development Manager

Keep Noise

Down When Making Low-Level Measurements

C

haracterizing electronic devices such as fieldeffect transistors (FETs) and carbon nanotubes (CNTs) can be a challenge because it requires making measurements of very low currents, often at or below the noise level of the test system. To make these measurements successfully, you need to know what type of test equipment to use, the different sources of measurement error, and the appropriate techniques to minimize these errors.

A number of instruments are available for making lowcurrent measurements. One of these is the digital multimeter (DMM). Although a low-cost, 3-1/2 digit handheld DMM isn’t an appropriate solution for a lowlevel measurement, high-precision laboratory DMMs are available that can measure current levels as low as 10pA. Other options for measuring lower-level currents include picoammeters, electrometers, and source-measurement units (SMUs). Each type offers a different set of capabilities and ranges. For example, an electrometer can measure currents as low as the instrument’s input offset current, in some cases as low as one femto-amp.

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Some SMUs can measure currents as low as 400 attoamps.

Keep It Down!

The sensitivity of all these instruments is limited by noise, both internal and external to the test instrument itself. The source resistance of a device under test (DUT), for example, sets the level of Johnson current noise, which is low-level noise caused by temperature effects on electrons in a conductor. The lower the source resistance, the higher the Johnson noise.

Both temperature and noise bandwidth affect the Johnson current noise. A reduction in either parameter will also reduce the Johnson current noise. Cryogenic cooling, for example, is often used to reduce noise in amplifiers and other circuits in research studies such as superconductivity studies, but the cooling equipment required comes at significant cost. The noise bandwidth can be reduced by filtering, but this will slow down the measurement. The Johnson current noise could also be reduced by increasing a DUT’s source resistance, but this is rarely possible to do.

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TECHNICAL ARTICLE

Noise Current

10–6

1nA

–9

10

Joh

nso

1pA

nC

1fA

10–12

urr ent

No

10–15

ise

10–18

1aA

103 1kΩ

Figure 1

106 1MΩ

109 1GΩ

1012 1TΩ

1015 1PΩ

1018 1EΩ

Source Resistance

Insulators can also contribute to system noise. By using ceramic insulators, wearing gloves when touching them, and keeping them clean, you can minimize insulator noise caused by the piezoelectric effect and by contamination.

By using the right instrument, and minimizing noise sources when designing test systems, you can make very low-level current measurements successfully. For more information on this topic, see the Keithley app note, “Optimizing Low-Current Measurements and Instruments.” You can download it from the Keithley website.

About the Author

The coaxial cables used to interconnect test instruments to each other or to the DUT are another source of unwanted noise. Typical test cables can generate as much as tens of nano-amps when, due to vibration, their outer shields rub against the cable’s insulation. In some applications, such as nanotechnology and semiconductor research, the current generated by this effect may exceed the level of current to be measured from the DUT. To minimize this effect, use low-noise cables and prevent them from

Robert Green is a Senior Market Development Manager at Keithley Instruments focusing on low level measurement applications. During his 20-year career at Keithley, Mr. Green has been involved in the definition and introduction of a wide range of products including picoammeters, electrometers, digital multimeters, and temperature measurement products. He received a B.S. in Electrical Engineering from Cornell University and an M. S. in Electrical Engineering from Washington University, St. Louis, Missouri. ■

Coaxial Cable Outer Jacket

Insulation Center Conductor

Shield

Triaxial Cable Outer Jacket

Insulation Outer Shield

Insulation Inner Shield

Center Conductor

Figure 2

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TECHNICAL ARTICLE

flexing by securing them to the test bench.

1µA

Get the Datasheet and Order Samples http://www.intersil.com

6A Digital Synchronous Step-Down DC/DC Converter with Auto Compensation ZL2101

Features

The ZL2101 is a 6A digital converter with auto compensation and integrated power management that combines an integrated synchronous step-down DC/DC converter with key power management functions in a small package, resulting in a flexible and integrated solution.

• Integrated MOSFET Switches

The ZL2101 can provide an output voltage from 0.54V to 5.5V (with margin) from an input voltage between 4.5V and 14V. Internal low rDS(ON) synchronous power MOSFETs enable the ZL2101 to deliver continuous loads up to 6A with high efficiency.

An internal Schottky bootstrap diode reduces discrete component count. The ZL2101 also supports phase spreading to reduce system input capacitance.

• Snapshot™ Parametric Capture

Power management features such as digital soft-start delay and ramp, sequencing, tracking, and margining can be configured by simple pin-strapping or through an on-chip serial port. The ZL2101 uses the PMBus™ protocol for communication with a host controller and the Digital-DC bus for interoperability between other Zilker Labs devices.

• Test and Measurement Equipment

• 6A Continuous Output Current • ±1% Output Voltage Accuracy • Auto Compensation • I2C/SMBus Interface, PMBus Compatible • Internal Non-Volatile Memory (NVM)

Applications • Telecom, Networking, Storage equipment • Industrial Control Equipment • 5V and 12V Distributed Power Systems

Related Literature • AN2010 “Thermal and Layout Guidelines for Digital-DC™ Products” • AN2033 “Zilker Labs PMBus Command Set - DDC Products” • AN2035 “Compensation Using CompZL™”

100 VOUT = 3.3V

EFFICIENCY (%)

90 80 70 60 50 40 0.0

VIN = 12V fSW = 200kHz L = 6µH 1.0

2.0

3.0

4.0

5.0

6.0

IOUT (A)

FIGURE 1. ZL2101 EFFICIENCY

January 23, 2012 FN7730.0

Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2012 All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

Robert Berger

Embedded Software Specialist

Arduino

for mere m0rtals - PART 1 Disclaimer The views, opinions, positions or strategies expressed by the author and those providing comments are theirs alone, and do not necessarily reflect the views, opinions, positions or strategies of anybody else.

What or who is Arduino anyhow?

This is how the official Arduino site describes it [1]: Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It’s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.

History Once upon a time—well, in 2005 in Irvea, Italy—Massimo Banzi, David Cuartielles and Gianluca Martino started what’s know today as ”Arduino.” Insiders believe that the name comes from a pub close to the birthplace of the project, which in turn was named after Arduin of Ivrea, the main historical character of the town. ”Arduino” is an Italian masculine first name, meaning ”strong friend.”

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The English version of the name is ”Hardwin.” The vision of Massimo and David was to develop a device less expensive than other prototyping systems available at the time which would enable students to develop electronics in multidisciplinary projects.

Arduino is a simple system designed for creative people with little or ”no prior knowledge of electronics,” says Banzi. ”It’s cheap and open-source with lots of documentation written in a not-too-technical language.

Above all, it has a very welcoming attitude towards beginners and tries not to scare them too much.”

The ”rather unconventional” approach to make both hardware and software open-source was taken. I’ll talk more about this later on. It was a big risk, and although it was initially uncertain whether the production costs for the first boards, let alone the time spent for the software, could be covered—as history shows—all went well as

by October 2008; about 50,000 Arduino boards had been shipped and by February 2010 more than 120,000 [2] [3].

Just check the hardware specs of the Arduino UNO

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You can see Arduino The Documentary here.

Stay tuned to find out if, and, or why we should bother in the next part of this series of articles!

References [1] ”Arduino” Figure 1: That’s how an Arduino UNO looks like.

[2] ”Arduino on Wikipedia” [3] ”Arduino on p2pfoundation”

Microcontroller

ATmega328

Operating Voltage

5V

Input Voltage (recommended)

7-12V

Input Voltage (limits)

6-20V

Digital I/O Pins

14 (of which 6 provide PWM output)

Analog Input Pins

6

DC Current per I/O Pin

40 mA

DC Current for 3.3V Pin

50 mA

Flash Memory

32 KB (ATmega 328) of which 0.5 KB used by bootloader

SRAM

2 KB (ATmega328)

EEPROM

1 KB (ATmega328)

Clock Speed

16 MHz

Figure 2

above. A board with a 16 MHz 8-bit AVR sold on planet Earth in 2011? Are these guys serious?

[4] ”Atmel AVR on Wikipedia” [5] ”Arduino Due preview” [6] ”LPCXpresso” [7] ”Raspberry Pi” About the Author Robert Berger is a highly respected and experienced embedded real-time expert and CEO of Reliable Embedded Systems, a leading embedded training consultancy. Robert consults and trains people all over the globe on a mission to help them create better embedded software. He specializes in training and consulting for embedded systems, from small real-time systems to multi-core embedded Linux. ■

Back in 1996 when the AVR (which is short for Alf (Egil Bogen) and Vegard (Wollan)’s Risc processor) was conceived by those two students at the Norwegian Institute of Technology in Trondheim, Norway, it was a pretty cool device: on chip flash, modified Harward architecture, one cycle per instruction (in most of the cases), in-system programmable, on-chip debugging [4]. Working with it back then you would pretty soon realize that it was much less of a pain to write C programs for it than for an 8051 or a PIC, which was what I had lying around in my lab at that point in time.

Nowadays, unless really low power consumption is required, a big leap forward toward 32-bit ARM processors [5] can be observed and the Arduino UNO

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does not look like anything close to a state-of-the-art embedded hardware platform. In the same price range you could get ARM Cortex-M3 boards [6] and even MIPS boards running Linux [7]. So why should we professionals even bother looking into this outdated hobbyist technology?

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