Cryptography-Enabled 32-bit Microcontroller for IoT Designs

Microchip Technology’s CEC1302 hardware crypto-enabled 32-bit microcontroller enables you to easily add security to Internet of Things (IoT) devices. Enabling pre-boot authentication of system firmware, the microcontroller prevents a variety of security attacks (e.g., man-in-the-middle, denial-of-service, and backdoor). You can also use it to authenticate firmware updates.Microchip CEC1302

The CEC1302’s features, benefits, and specs:

  • Private key and customer programming flexibility
  • Power drain savings and improved execution of application performance
  • 32-bit microcontroller with an ARM Cortex-M4 core
  • The hardware-enabled public key engine of the device is 20 to 50 times faster than firmware-enabled algorithms

In order to quickly develop applications with the CEC1302, use MikroElektronika’s CEC1302 Clicker (MIKROE-1970) and CEC1302 Clicker 2 (MIKROE-1969). You can use the boards with MikroElektronika’s complete development toolchain for Microchip CEC1302 ARM Cortex-M4 MCUs.

The CEC1302 (CEC1302D-SZ-C0) is available today for sampling and volume production in a 144-WFBGA package starting at $1.75 each in 10,000-unit quantities.

Source: Microchip Technology

Telit Announces IoT Innovation Conference

Telit announced that it will soon open registration for the 2016 Telit IoT Innovation Conference, which will take place on Tuesday, September 6, 2016 at Caesars Palace in Las Vegas. The one-day, multi-track conference will feature business use cases and provide you with tools for building your network and enabling connected devices.

As an attendee, you can study real IoT business use cases, network with IoT innovators, discover new technologies for IoT solution deployment, connect with partners, and learn more about Telit products and its IoT ecosystem.

Registration opens soon!

Source: Telit

IAR Systems Supports Wireless Gecko SoCs for IoT connectivity

IAR Systems now supports Silicon Labs Wireless Gecko SoCs, which provide scalable solutions and include Thread and ZigBee stacks for mesh networks, intuitive radio interface software for proprietary protocols, and Bluetooth Low Energy technology for point-to-point connectivity. The IAR Embedded Workbench development provides extensive debugging and profiling possibilities such as complex code and data breakpoints, run-time stack analysis, call stack visualization, code coverage analysis, and integrated monitoring of power consumption. IAR Systems also offers integrated add-on tools for static analysis and run-time analysis.

Support for the Wireless Gecko SoCs is available using IAR Embedded Workbench for ARM, from version 7.60. Free trial versions are available.

Source: IAR Systems

The Future of IoT Security

With the onset of Internet of Things (IoT) technology, an enormous number of devices are now accessible via the Internet and are therefore vulnerable to cyberattack. Society is still adjusting to the fact that devices that people used to trust can now betray them in unexpected ways. Your television may expose your conversations, your printer may divulge your documents, and your fitness monitor may reveal your health information. All of these attacks become possible in the presence of IoT devices which are not designed with security in mind. System designers are trained to evaluate system design options in terms of their impact on system characteristics such as power, performance, and time-to-market, but security is a property which is less well understood. Designers of IoT devices need to have the ability to consider, both qualitatively and quantitatively, how design alternatives affect the security of the system. To do that, designers must understand the essential aspects of common cyberattacks.

The nature of cyberattacks is broad and ever-changing as attackers alter their techniques over time. However, there are a number of attack themes which are fundamental to many cyberattacks and change only infrequently. Designers need to understand these important attack themes and how to defend against them. A good example is a vulnerability to a buffer overflow attack which is usually a result of weak coding practices, such as neglecting to verify that the amount of data written into a buffer is not greater than the size of the buffer. Defense against buffer overflow can likely be achieved through static code analysis and proper testing techniques, without the need to include any security components in the IoT device.

Another attack against IoT devices is a battery draining attack which consumes power by exploiting features of the network communication protocol being used by the device. Different protocols, and their interface controllers, have different degrees of vulnerability to such attacks, and the system designer needs to be aware of this when selecting a communication protocol.

This essay appears in Circuit Cellar 309, April 2016. Subscribe to Circuit Cellar to read project articles, essays, interviews, and tutorials every month!

Defending against some attacks will require the use of software and hardware components which are dedicated to security-related tasks. Such components incur overheads which must be considered by the designer. A common example is whether or not to use encryption, what type of encryption, and whether that encryption should be implemented in hardware or software. Besides the power and cost trade-offs involved, the designer will need to be able to estimate how well each type of encryption protects the system from, for example, a man-in-the-middle attack which intercepts communications with other devices.

IoT security is clearly an important design property which must be considered by designers who understand the complexities of cybersecurity. A problem for the field of IoT is that there is a shortage of IoT designers who understand cybersecurity. There is a range of possible solutions to address the shortage problem which vary based on who takes responsibility to find a solution. One alternative is education or training to ensure that designers are aware of the complexities of the security problem and can address them during the design process. Individual IoT designers may take responsibility for their own training, which means that the designer will individually seek out learning materials and possibly courses. As a professor I feel that individuals should always take responsibility for their own education, but in practice this is difficult and may not consistently result in the best outcome for all concerned. An individual who is not familiar with security will have a hard time determining what is important to learn and what is not, so they may waste time and money on education with no real value. In my role as Vice Chair of Undergraduate Studies, I am frequently asked about what a student needs to learn to be productive in industry, but if an individual cannot find an appropriate mentor to provide them with some direction, then their attempts at education may not be fruitful.

Another alternative is to place the responsibility for the development of secure IoT devices on the companies which employ the designers and sell the IoT devices. For this to happen, company managers must first accept that security costs money and that security is worth some expenditure. As long as security is seen as an overhead with no direct financial benefit, industry is not be motivated to make the necessary changes to build secure systems. Too often, security is largely ignored until a successful cyberattack against a company is publicized and the company suffers in terms of reputation and possible lawsuits. Industry needs to accept the importance of security upfront to avoid the more significant costs of dealing with successful attacks.

Companies can take several different approaches to ensuring security including guaranteeing that their designers are appropriately knowledgeable about IoT security. A salary premium for security experts could motivate employees to take responsibility for their own security education. In-house corporate training can be provided to employees whose job responsibilities necessitate an understanding of security. Employers can outsource and pay for education at local or online schools. When a project is particularly security-sensitive requiring more expertise than is available internally, a contractor with the appropriate security expertise can be brought in. All of these options incur different costs which would need to be justified by the need for security in the market where the IoT devices will be used.

Eventually, a mixture of these approaches should be employed to achieve the best, and most secure, results. Individual designers need to make every effort to learn about security issues, and employers need to motivate them with appropriate salaries and facilitate their efforts by providing opportunities for education. The lack of security of current IoT devices has been used as an argument against their adoption, but there seems to be no stopping the growing use of the IoT. At the same time, cyberattacks are also growing in number, sophistication, and financial impact. Security needs to be a first-class design consideration for IoT systems, on par with cost, power, and the other constraints that embedded designers have always dealt with.

Associate Professor Ian G. Harris earned a BS in Computer Science at MIT and MS and PhD degrees in Computer Science from the University of California San Diego. He is currently Vice Chair of Undergraduate Education in the Computer Science Department at the University of California Irvine. His research group focuses on the security and verification of Internet of Things systems. He also teaches an IoT specialization entitled “An Introduction to Programming the Internet of Things.”

New Low-Power Embedded Wi-Fi Solutions for the IoT

Microchip Technology recently launched four low-power, highly integrated solutions that enable Wi-Fi and networking capability to be embedded into a wide variety of devices, including Internet of Things (IoT) applications. These four modules provide complete solutions for 802.11b/g/n and are industry-certified in a variety of countries.Microcontroller  MRF24

The new RN1810 and RN1810E are stand-alone, surface-mount WiFly radio modules that include a TCP/IP stack, cryptographic accelerator, power management subsystem, 2.4-GHz 802.11b/g/n-compliant transceivers, and 2.4 RF power amplifier. You can pair them with any microcontroller and configure them using simple ASCII commands. WiFly provides a simple data pipe for sending data over a Wi-Fi network, requiring no prior Wi-Fi experience to get a product connected. Once configured, the device automatically accesses a Wi-Fi network and sends and receives serial data. The RN1810 features an integrated PCB antenna. The RN1810E supports an external antenna.

The new MRF24WN0MA and MRF24WN0MB are Wi-Fi modules that interface with Microchip’s PIC32 microcontrollers and support Microchip’s MPLAB Harmony integrated software framework with a TCP/IP stack that can be downloaded for free at The modules connect to the microcontroller via a four-wire SPI. They area an ideal solution for low-power, low-data-rate Wi-Fi sensor networks, home automation, building automation, and consumer applications. In addition, an MRF24WN0MA has an integrated PCB antenna, while the MRF24WN0MB supports an external antenna.

The RN1810/E and MRF24WN0MA/B are now available and start at $13.05 each in 1,000-unit quantities. Also available is the $34.95 MRF24WN0MA Wi-Fi PICtail/PICtail Plus Daughter Board, a demonstration board for evaluating Wi-Fi connectivity using PIC microcontrollers and the MRF24WN0MA module (part # AC164153). In addition, a $49.95 RN1810 Wi-Fi PICtail/PICtail Plus Daughter Board is available today with a fully integrated TCP/IP stack and USB interface for easy plug-and-play development with a PC (part # RN-1810-PICTAIL).

Source: Microchip Technology

The Future of Wireless: Imagination Drives Innovation

Wireless system design is one of the hottest fields in electrical engineering. We recently asked 10 engineers to prognosticate on the future of wireless technology. Alexander Popov, a Bulgaria-based engineer, writes:

These days, we are constantly connected to the Internet.5 Popov orange People expect quality service both at home and on the go. Cellular networks are meeting this demand with 4G and upcoming 5G technologies. A single person now uses as much bandwidth as an entire Internet provider 20 years ago. We are immersed in a pool of information, but are no longer its sole producers. The era of Internet of Things is upon us, and soon there will be more IoT devices than there are people. They require quite a different ecosystem than we people use. Тheir pattern of information flow is usually sporadic, with small chunks of data. Connecting to a generic Wi-Fi or cellular network is not efficient. IoT devices utilize well established protocols like Bluetooth LE and ZigBee, but dedicated ones like LPWAN and 6LoWPAN are also being developed and probably more will follow. We will see more sophisticated and intelligent wireless networks, probably sharing resources on different layers to form a larger WAN. An important aspect of IoT devices is their source of power. Energy harvesting and wireless power will evolve to become a standard part of the “smart” ecosystem. Improved technologies in chip manufacturing processes aid hardware not only by lowering power consumption and reducing size, but also with dedicated embedded communication stack and chip coils. The increased amount and different types of information will allow software technologies like cloud computing and big data analysis to thrive. With information so deep in our personal lives, we may see new security standards offering better protection for our privacy. All these new technologies alone will be valuable, but the possibilities they offer combined are only limited by our imaginations. Best be prepared to explore and sketch your ideas now! — Alexander Popov, Bulgaria (Director Product Management, Minerva Networks)

Low-Power 12 DOF Bluetooth Smart Sensor Development Platform

Dialog Semiconductor now offers a small, low-power 12 Degrees-of-Freedom (DOF) wireless smart sensor development kit for Internet of Things (IoT) applications, such as wearables, virtual reality, 3-D indoor mapping, and navigation. The DA14583 SmartBond Bluetooth Smart SoC is combined with Bosch Sensortec’s gyroscope, accelerometer, magnetometer, and environmental sensors. A 16 mm × 15 mm PCB is supplied as a dongle in a plastic housing. Current consumption is only 1.3 mA (typical) when streaming sensor data; it’s less than 110 µA in advertising mode and under 11 µA in power-save mode.Dialog DS025

The complementary software development kit (SDK) includes Dialog’s SmartFusion smart sensor library for data acquisition, auto-calibration, and sensor data fusion. It runs on the DA14583’s embedded Cortex M0 processor. The DA14583 has an ARM Cortex-M0 baseband processor with an integrated ultra-low power Bluetooth Smart radio. The development kit includes the following Bosch sensors: a BMI160 six-axis inertial measurement unit, a BMM150 three-axis geomagnetic field sensor, and a BME280 integrated environmental unit, which measures pressure, temperature, and humidity.

Source: Dialog Semiconductor

The Future of Wireless: Deployment Matters

Each day, wireless technology becomes more pervasive as new electronics systems hit the market and connect to the Internet. We recently asked 10 engineers to prognosticate on the future of wireless technology. Penn State Professor Chris Coulston writes:9 Coulston green

With the Internet of Things still the big thing, we should expect exciting developments in embedded wireless in 2016 and beyond. Incremental advances in speed and power consumption will allow manufactures to brag about having the latest and greatest chip. However, all this potential is lost unless you can deploy it easily. The Futurelec FT-232 serial-to-USB bridge is a success because it trades off some of the functionality of a complex protocol for a more familiar, less burdensome, protocol.  The demand for simplified protocols should drive manufacturers to develop solutions making complex protocols more accessible. Cutting the cord means different things to different people. While Bluetooth Low Energy (BLE) has allowed a wide swath of gadgets to go wireless, these devices still require the presence of some intermediary (like a smart phone) to manage data transfer to the cloud. Expect to see the development of intermediate technologies enabling BLE to “cut the cord” to smart phones. Security of wireless communication will continue to be an important element of any conversation involving new wireless technology. Fortunately, the theoretical tools need to secure communication are well understood. Expect to see these tools trickle down as standard subsystems in embedded processors. The automotive industry is set to transform itself with self-driving cars. This revolution in transportation must be accompanied by wireless technologies allowing our cars to talk to our devices, each other and perhaps the roadways. This is an area that is ripe for some surprising and exciting developments enabling developers to innovate in this new domain. We live in interesting times with embedded systems playing a large role in consumer and industrial systems. With better and more accessible technology in your grasp, I hope that you have great and innovative 2016! — Chris Coulston, United States (Associate Professor, Electrical & Computer Engineering, Penn State Erie)

Technical Preview of Windows 10 IoT Core on ARM Platform

Toradex recently announced the availability of a technical preview of the Windows 10 IoT Core on an ARM-based System on Module (SOM). The technical preview enables embedded developers to evaluate the new features of Windows 10 IoT Core on an industrial-grade embedded computing platform. According to Toradex, a starter kit—available for a limited time at a promotional price—is available with a Colibri T30 SOM and Iris carrier board with required accessories.

The technical preview is based on Colibri T30 powered by NVIDIA’s Tegra 3 ARM Cortex-A9 Quad Core embedded processor. Part of the Azure IoT Certified Program, the Colibri T30 supports accelerated DirectX graphics and provides low-level hardware access.

Although the technical preview’s has a limited number of features, Toradex announced that it intends to gather customer feedback and later extend features and add Windows 10 IoT Core support for its other ARM-based SOMs.

Source: Toradex

Industry 4.0: The Industrial IoT and the Future

The Internet of Things (IoT) is everywhere. Industry 4.0 is becoming serious and many companies develop hardware and software solutions. Relayr is a company with an interesting focus on the IoT and bringing industry to the cloud. Wissa Hettinga interviewed Jaime Gonzalez-Arintero Berciano, a Relayr developer and product evangelist, about the company, its technology, and future of innovation in the IoT space.

The Future of Wireless: IoT “Connect Anywhere” Solutions

Wireless communications have revolutionized virtually every industry, from healthcare to defense to consumer electronics. We recently asked 10 engineers to prognosticate on the future of wireless technology. France-based engineer Robert Lacoste writes:3 Lacoste purple

I don’t know if the forecasts about the Internet of Things (IoT) are realistic (some analysts predict from 20 to 100 billion devices in the next five years), but I’m sure it will be a huge market. And 99% of IoT products are and will be wireless. Currently, the vast majority of “things” connect to the Internet through a user’s smartphone, used as a gateway typically through a Bluetooth Smart link. Other devices (e.g., home control or smart metering) require the installation of a dedicated fixed RF-to-Internet gateway, using ZigBee, 6lowPan, or something similar. But the next big thing will be the availability of “connect anywhere” solutions, through low-power wide area networks, nicknamed LPWA. Even if the underlying technology is not actually new (i.e., using very low bit rates to achieve long range at low powers), the contenders are numerous: LORA Alliance, INGENU, SIGFOX, WEIGHTLESS, and a couple of others. At the same time, the traditional telcos are developing very similar solutions using cellular bands and variants of the 3GPP protocols. EC-GSM, LTE-MTC, and NB-IOT are the most discussed alternatives. So, the first big question is this: Which one (or ones, as a one-size-fits-all solution is unlikely) will be the winner? The second big question has to do with whether or not IoT products will be useful for society. But that’s another story! — Robert Lacoste, France (Founder, Alciom; Columnist, Circuit Cellar)

New MCUs Combine Hardware Cryptography with Advanced Energy Management

Silicon Labs recently introduced two new EFM32 Gecko microcontroller (MCU) families that feature advanced security and energy-management technologies. The Jade Gecko and Pearl Gecko MCUs combine a hardware cryptography engine, flexible low-energy modes, an on-chip DC-DC converter, and scalable memory options backed by Silicon Labs’s Simplicity Studio tools. The MCUs target an array of energy-sensitive and battery-powered devices, such as wearables and IoT node applications.Silicon Labs jade pearl

Jade and Pearl Gecko MCUs are meant to equip IoT-connected devices with the latest security technologies to thwart hackers. They feature a hardware cryptography engine providing fast, energy-efficient, autonomous encryption and decryption for Internet security protocols (e.g., TLS/SSL) with minimal CPU intervention. The on-chip crypto-accelerator supports advanced algorithms such as AES with 128- or 256-bit keys, elliptical curve cryptography (ECC), SHA-1, and SHA-224/256. Hardware cryptography enables developers to meet evolving IoT security requirements more efficiently than with conventional software-only techniques often required by competing MCUs.

Based respectively on ARM Cortex-M3 and M4 cores, Jade and Pearl Gecko MCUs provide ample performance for connected devices while enabling developers to optimize battery life or use smaller batteries for space-constrained designs. The new MCUs feature an enhanced peripheral reflex system (PRS) that lets low-power peripherals operate autonomously while the MCU core sleeps, allowing connected devices to sleep longer, thus extending battery life. Energy-saving low active-mode current (63 µA/MHz) enables computationally intensive tasks to execute faster. Low sleep-mode current (1.4 µA down to 30 nA) and ultra-fast wake-up/sleep transitions further minimize energy consumption.

Jade and Pearl Gecko MCUs also integrate a high-efficiency DC-DC buck converter. Offering a total current capacity of 200 mA, the on-chip converter can provide a power rail for other system components in addition to powering the MCU. This power management innovation reduces BOM cost and board area by eliminating the need for an external DC-DC converter.

Engineering samples of EFM32JG Jade Gecko and EFM32PG Pearl Gecko MCUs are available now in 5 mm × 5 mm QFN32 and 7 mm × 7 mm QFN48 packages. Production quantities are planned for Q2 2016. Jade Gecko pricing begins at $1.24 in 10,000-unit quantities. The Pearl Gecko pricing begins at $1.65 in 10,000-unit quantities. The SLSTK3401A EFM32PG Pearl Gecko Starter Kit costs $29.99.

Source: Silicon Labs

The Internet of Things: Cell Modem Certification

In the multipart article series, “The Internet of Things,” Bob Japenga details how to connect simple devices wirelessly to the Internet.  This month, he covers at the requirements for, the cost of, and some of the problems with cell modem certification for embedded systems.

Japenga writes:

Almost every month, I get a call from some budding new entrepreneur with a great idea for an Internet of Things (IoT) product. Before we get too far along in the conversation, I ask the question: “What is your budget for cell modem certification?” More often than not, the answer is: “What is that and how much does it cost?” This month I would like to address these two questions as well as address the major issues we have had in cell certification. As always, this is a big topic that we cover in thin slices.

What are the requirements?

All cell modems are required to be certified by cell carriers prior to sale to customers like you and me. However, just because the cell modem is certified for a particular carrier, you are still required to certify the device that incorporates this modem. This makes sense for a lot of the certification requirements. For example, just because the cell modem has an acceptable receiver sensitivity and good robust transmit power, it doesn’t mean that your design has met these requirements. This necessitates that you separately test your device to the carrier’s requirements. The only exception to this is when the cell modem is self-contained and not an integral part of your design. For purposes of brevity, I will only cover the requirements for North America. Nor will I go over definitions defined in previous articles in this series.


If your IoT device is going to use AT&T (3G or 4G), you will be required to pass PTCRB and AT&T certification testing. PTCRB (an obsolete acronym that used to stand for PCS Type Certification Review Board) is an independent certification agency used by some North American cell carriers, including AT&T. Testing to the PTCRB standard is done by a third-party independent test lab. You, the designer, are responsible to contract with one of these independent test labs. Cetecom ( and 7Layers ( are two such labs that we have worked with.

After you have passed the PTCRB tests, you need to obtain AT&T approval. Once scheduled, PTCRB testing will take three to four weeks. AT&T approval takes another one to two weeks. The lab costs depend on the particular test lab, but it will cost between $20,000 to $40,000 for GSM modems and $60,000 to $70,000 for LTE modems.


The process of certification for Verizon 3G (CDMA) and 4G (LTE) is done directly through Verizon. This testing can be done through an independent lab or through Verizon. Verizon recommends that you pre-certify your product through its Innovation Center. There you can work with Verizon test engineers and technicians to make sure your design is ready for prime time before you go to certification. Verizon provides this service to qualified companies.

Once you have pre-certified, then you can contract with an outside independent certification lab (e.g., Cetecom, 7Layers, and Intertek). The cost for a CDMA certification will be $15,000 to $20,000 while the LTE certification can cost as much as $70,000. Once scheduled, the pre-certification timeframe is about two to three weeks with another three to four weeks for certification once it is scheduled.


If you are deploying a GSM modem on the Aeris network in North America, you will require PTCRB certification as well as Aeris certification. The cost and schedule are the same as I described earlier.  If you are deploying a CDMA solution, you only require Aeris certification (which has the least stringent requirements of all the carriers, is free and takes a week or two). Aeris also allows you to self-certify for small volumes of installations.

Technical Requirements

Let’s summarize the technical requirements for certification and our experience with these.

Total Isotropic Sensitivity (TIS): All carriers for all radio access technologies require a minimum receiver sensitivity. Basically, this test determines how weak a signal from the cell tower your device can respond to. This is one of the situations where certification is your friend—not your enemy. You don’t want to deploy your great new idea and have a lot of “Can you hear me now?” problems.

There are three primary ways that we have improved our TIS. First you must make your device whisper quiet in terms of radiated emissions in and around the receiver frequencies. If you thought meeting FCC Class B EMC requirements were tough, your requirements for making your device whisper quiet to meet the TIS requirements are much more stringent. I’ll talk more about this when I discuss EMC requirements.

Next is your choice of antenna. We have been unsuccessful meeting TIS requirements without using antennas significantly larger than used in our cell phones. We have often wondered how all of our cell phones met the TIS requirements with their very small antennas. I will leave it to your research and your imagination as to how cell phones are passing the cell carriers TIS requirements with such small antennas. In the words of Deep Throat, “Follow the money!”

Finally, your antenna should be placed as far away from any metal as possible and should have a nonmetallic path to the outside world. One product we had was mounted in a large metal base mounted to an outside wall that shadowed the entire hemisphere behind the product. PTCRB testing of this product required it to meet the TIS requirements completely and evenly around the sphere. We could not get the test lab to relax this 360° requirement. Instead we removed the product from its real world enclosure and performed the testing in a nonrealistic environment. This seemed ludicrous to us since we wanted to test it in the real world enclosure. This resulted in uncertainty on our part once the product passed certification. We were not certain how it would work in the real world when it had this metal box shadowing the back hemisphere. Thankfully, we have deployed more than 50,000 of these with no TIS problems.

Total Radiated Power (TRP): As with TIS, certification testing is your friend concerning TRP. The carriers have similar stringent requirements for TRP. Here your design must carefully place and tune your antenna to obtain the maximum TRP. A little bit of movement of the antenna can make a significant improvement or degradation of your radiated performance.

Another critical requirement for your design is that your power supplies must be capable of instantaneously delivering 1 to 2 A of power when a transmission takes place. Cell modems have one of the more demanding power supply requirements that we have worked with.

One design flaw we saw in one design was having the ground plane under the u.fl connector going to the external antenna. This ground plane was absorbing a significant amount of both outgoing (TRP) and incoming radiation (TIS).  Your antenna connector must not be near either the ground or power plane.

Electromagnetic Compatibility/Electromagnetic Interference (EMC/EMI): We did a preliminary EMC scan on our first IoT cell modem design and were very happy that we met FCC Class B requirements for radiated spurious emissions (EMI) with flying colors. What we didn’t know was that PTCRB had its own idle mode radiated spurious emissions requirements which were far more stringent than FCC Class B. Initially, we were not even close to meeting these PTCRB requirements. We hired an RF expert to help us. His first suggestion was for us to rip apart an old cell phone and tell him what we saw. When we did this, we saw that the entire circuit board was covered with EMI shield cans (see Photo 1). “That’s what you need to do with your design.” So, after designing the circuit with all of the EMI suppression techniques and good layout practices that we knew, we still needed to populate the board with five shield cans.Japenga CC305

Data Retry: If you were a carrier, you would not want to have devices tie up band width with incessant retries. So each carrier has its own unique retry requirements. Some of this retry logic is handled by your cell modem (retries connecting to the cell tower). But in addition, your application software must meet the retry requirements of each carrier. Generally, we are designing systems that use less than 1 MB of data every month so we don’t want too many retries at the application level either.

Data Throughput: Remembering that carriers are trying to get as much data through as quickly as possible, each carrier has data throughput requirements for some radio access technologies. This requirement is strictly a function of your cell modem chip. Since your chip is already certified for the particular carrier, it has already passed these tests. Unfortunately, some carriers require you to retest many of these requirements that have absolutely no bearing on your design unless you have modified the cell modem chip (which you can do). It is understandable that the carriers need to protect their network from rogue devices but I feel very strongly that they need to simplify this area of certification. So chip makers, carriers, and PTCRB board, if you are listening, isn’t there a better way to detect if we have modified the chip’s operation? For example, if there was a flag in the chip that indicated that the radio parameters have been altered in such a way that the carrier/PTCRB certification has been compromised, certification could be made much simpler.

A lot of these tests are very complicated and are being performed to moving standards. We were certifying one product that was failing tests that had nothing to do with our design—only with the cell modem chip. What it boiled down to was this: The chip was tested and passed Version A certification requirements. More stringent requirements were created later (Version B) which our modem failed. Since we were only required to pass Version A requirements, we should have been able to re-run the tests to Version A. The problem was that the certification lab did not have test equipment that ran Version A tests! Hopefully you see the problem. I strongly think this must change as it wastes a lot of time and money in the certification process. We have wasted several months trying to get this device ready for sale.


In 2010, I was at a football game with my grandsons and 103,000 other people. One of my grandsons was not able to make the game, so I wanted to send him a text at kickoff. Even though I had maximum signal strength, I could not make the call. When I looked around the stadium, it was clear that many wanted to text or call at the same time. Cell phones must work in close proximity to other cell phones. Most M2M devices do not have that requirement. PTCRB certification requires that your device not be transmitting on any frequencies other than the frequency you are licensed to transmit on so as to avoid interfering with nearby cell phones. The first device we took through PTCRB testing failed these tests at a couple of points. What we discovered was that every diode in your design acts as a re-radiator of the radio signal you are transmitting. And it radiates at one of the harmonics of the transmit frequency. This must be squelched or you will fail your Harmonic Radiated Spurious Emissions (RSE) tests.


Even after doing another spin of the board with small capacitors around every diode, we were still failing Harmonic RSE at a couple of frequencies by a few decibels. The product was already several months late. Should we do another spin of the board after we find the diode we missed? At this point, I pushed through a waiver. This was a formal request to the PTCRB board for an exception to the requirements. Our unit was stationary. Our unit did not operate in the presence of other cell phones. Come on, we are talking about only 2 db! Thankfully and quickly, the waiver got approved. We had our first cell modem-based IoT device ready to ship. So the moral of the story is: Work with the certifying agency. Some requirements that apply to cell phones do not apply to M2M products. Sometimes the certification process is our friend but a lot of time it is just a pain in the neck.

Certify first

You have a good IoT idea that will make this world a better place. But before you bring it to fruition, you will need to pass the necessary certification tests imposed on you by the cell network carriers. This article gives you a thin slice as to what’s involved and what it will cost.

This article appears in Circuit Cellar 305, 2015.

Bluetooth Smart SoCs Links Wearables to Apps for WeChat

Dialog Semiconductor recently announced its support for WeChat’s communications protocol with the launch of its WeChat SDK. With the kit, you can quickly add Bluetooth connectivity between WeChat apps and wearables and other IoT devices. Dialog DA14580 Dialog’s development kit is available now and includes a protocol stack for the WeChat communication layer. The SDK—which is based on the DA1458x family of SmartBond SoCs—enables you to reduce the overall development time for connecting their products wirelessly to WeChat apps. Your users can control wearable devices via the app and share information via the platform.

DA1458x SoCs combine a Bluetooth low-energy radio with an ARM Cortex-M0 application processor. With intelligent power management circuitry and accessible processor resources via 32 GPIOs,you can build fully hosted applications.

The SmartBond WeChat SDK enables efficient coding and comes with SmartSnippets software development environment, which is based on Keil µVision tools.

Source: Dialog Semiconductor

Innovative Product Design: An Interview with Rich Legrand

Rich Legrand founded Charmed Labs in 2002 to develop and sell innovative robotics-related designs, including the Xport Robot Kit, the Qwerk robot controller, the GigaPan robotic camera mount, and the Pixy vision sensor. He recently told us about his background, passion for robotics, and interest in open-source hardware.

Legrand-IMG_5660CIRCUIT CELLAR: Tell us a bit about your background. When did you first get started with electronics and engineering?

RICH: Back in 1982 when I was 12, one of my older brother’s friends was what they called a “whiz kid.” I would show up uninvited at his place because he was always creating something new, and he didn’t treat me like a snotty-nosed kid (which I was). On one particular afternoon he had disassembled a Big Trak toy (remember those?) and connected it to his Atari 800, so the Atari could control its movements. He wrote a simple BASIC program to read the joystick movements and translate them to Big Trak movements. You could then hit the return key and the Atari would play back the motions you just made. There were relays clicking and LEDs flashing, and the Big Trak did exactly what you told it to do. I had never seen a computer do this before, and I was absolutely amazed. I wanted to learn as much as I could about electronics after that. And I’m still learning, of course.

CIRCUIT CELLAR: You studied electrical engineering at both Rice University and North Carolina State University. Why electrical engineering?

RICH: I think it goes back to when I was 12 and trying to learn more about robotics. With a limited budget, it was largely a question of what I get my hands on. Back then you could go into Radio Shack and buy a handful of 7400 series parts and create something simple, but pretty amazing. Forrest Mims’s books (also available at Radio Shack) were full of inspiring circuit designs. And Steve Ciarcia’s “Circuit Cellar” column in Byte magazine focused on seat-of-the-pants electronics projects you could build yourself. The only tools you needed were a soldering iron, a voltmeter, and a logic probe. I think young people today see a similar landscape where it’s easier to get involved in electrical engineering than say mechanical engineering (although 3-D printing might change this). The Internet is full of source material and the hardware (computers, microcontrollers, power supplies, etc.) is lower-cost and easier to find. The Arduino is a good example of this. It has its own ecosystem from which you can launch practically any project or idea.

CIRCUIT CELLAR: Photography factors in a lot of your work and work history. Is photography a passion of yours?

RICH: I don’t think so, but I enjoy photography. Image processing, image understanding, machine vision—the idea that you can extract useful information from a digital image with a piece of software, an algorithm. It’s a cool idea to me because you can have multiple vision algorithms and effectively have several sensors in one package. Or in the case of Gigapan, being able to create a gigapixel imager from a fairly low-cost point-and-shoot camera, some motors, and customized photo stitching software. I’m a hardware guy at heart, but hardware tends to be expensive. Combining inexpensive hardware with software to create something that’s lower-cost—it sounds like a pretty niche idea, but these are the projects that I seem to fall for over and over again. Working on these projects is what I really enjoy.

CIRCUIT CELLAR: Prior to your current gig at Charmed Labs, you were with Gigapan Systems, which you co-founded. Tell us about how you came to launch Gigapan.

RICH: Gigapan is robotic camera mount that allows practically anyone with a digital camera to make high-resolution panoramas. The basic idea is that you take a camera with high resolution but narrow field-of-view (high-zoom) to capture a mosaic of pictures that can be later stitched together with software to form a much larger, highly-detailed panorama of the subject, whether it’s the Grand Canyon or the cockpit of the Space Shuttle. This technique is used by the Mars rovers, so it’s not surprising that a NASA engineer (Randy Sargent) first conceived Gigapan. Charmed Labs got a chance to bid on the hardware, and we designed and manufactured the first Gigapan units as part of a public beta program. (The beta was funded by Carnegie Mellon University through donations from NASA and Google.) The beta garnered enough attention to get investors and start a company to focus on Gigapan, which we did. We were on CNN, we were mentioned on Jay Leno. It was a fun and exciting time!

he first Xport was a simple circuit board with flash for program storage and an FPGA for programmable I/O.

The first Xport was a simple circuit board with flash for program storage and an FPGA for programmable I/O.

CIRCUIT CELLAR: In a 2004 article, “Closed-Loop Motion Control for Mobile Robotics“ (Circuit Cellar 169), you introduced us to your first product, the Xport. How did you come to design the Xport?

RICH: When the Gameboy Advance was announced back in 1999, I thought it was a perfect robot platform. It had a color LCD and a powerful 32-bit processor, it was optimized for battery power, and it was low-cost. The pitch went something like: “For $40 you can buy a cartridge for your Gameboy that allows you to play a game. For $99 you can buy a cartridge with motors and sensors that turns your Gameboy into a robot.” So the Gameboy becomes the “brains” of the robot if you will. I didn’t know what the robot would do exactly, other than be cool and robot-like, and I didn’t know how to land a consumer electronics product on the shelves of Toys “R” Us, so I tackled some of the bigger technical problems instead, like how to turn the Gameboy into an embedded system with the required I/O for robotics. I ordered a Gameboy from Japan through eBay prior to the US release and reverse-engineered the cartridge port. The first “Xport” prototype was working not long after the first Gameboys showed up in US stores, so that was pretty cool. It was a simple circuit board that plugged into the Gamboy’s cartridge port. It had flash for program storage and an FPGA for programmable I/O. The Xport seemed like an interesting product by itself, so I decided to sell it. I quit my job as a software engineer and started Charmed Labs.

CIRCUIT CELLAR: Tell us about the Xport Botball Controller (XBC).

RICH: The Xport turned the Gameboy into an embedded system with lots of I/O, but my real goal was to make a robot. So I added more electronics around the Xport for motor control, sensor inputs, a simple vision system, even Bluetooth. I sold it online for a while before the folks at Botball expressed interest in using it for their robot competition, which is geared for middle school and high school students. Building a robot out of a Gameboy was a compelling idea, especially for kids, and tens of thousands of students used the XBC to learn about engineering—that was really great. I never got the Gameboy robot on the shelves of Toys “R” Us, but it was a really happy ending to the project.

CIRCUIT CELLAR: Charmed Labs collaborated with the Carnegie Mellon CREATE Lab on the Qwerk robot controller. How did you end up collaborating with CMU?

RICH: I met Illah Nourbakhsh who runs the CREATE lab at a robot competition back when he was a grad student. His lab’s Telepresence Robotics Kit (TeRK) was created in part to address the falling rate of computer science graduates in the US. The idea was to create a curriculum that featured robotics to help attract more students to the field. Qwerk was an embedded Linux system that allowed you make a telepresence robot easily. You could literally plug in some motors, a webcam, and a battery, and fire up a web browser and become “telepresent” through the robot. We designed and manufactured Qwerk for a couple years before we licensed it.

The Qwerk

The Qwerk

CIRCUIT CELLAR: Pixy is a cool vision sensor for robotics that you can teach to track objects. What was the impetus for that design?

RICH: Pixy is actually the fifth version of the CMUcam. The first CMUcam was invented at  Carnegie Mellon by Anthony Rowe back in 2000 when he was a graduate student. I got involved on a bit of a lark. NXP Semiconductors had just announced a processor that looked like an good fit for a low-cost vision sensor, so I sent Anthony a heads-up, that’s all. He was looking for someone to help with the next version of CMUcam, so it was a happy coincidence.

The Pixy vision sensor

The Pixy vision sensor

CIRCUIT CELLAR: You launched Pixy in 2013 on Kickstarter. Would you recommend Kickstarter to Circuit Cellar readers who are thinking of launching a hardware product?

RICH: Before crowdfunding was a thing, you either had to self-fund or convince a few investors to contribute a decent amount of cash based on the premise that you had a good idea. And the investors typically didn’t have your background or perspective, so it was usually a difficult sell. With crowdfunding, a couple hundred people with similar backgrounds and perspectives contribute $50 (or so) in exchange for becoming the very first customers. It’s an easier path I think, and it’s a great fit for products like Pixy that have a limited but enthusiastic audience. I think of crowdfunding as a cost-effective marketing strategy. Sites like Kickstarter get huge amounts of traffic, and getting your idea in front of such a large audience is usually expensive—cost-prohibitive in my case. It also answers two important questions for hardware makers: Are enough people interested in this thing to make it worthwhile? And if it is worthwhile, how many should I make?

But I really didn’t think many people would be interested in a vision sensor for hobbyist robotics, so when faced with the task of creating a Kickstarter for Pixy, I thought of lots of excuses not to move forward with it. Case in point—if your Kickstarter campaign fails, it’s public Internet knowledge. (Yikes!) But I’m always telling my boys that you learn more from your mistakes than from your successes, so it seemed pretty lame that I was dragging my heals on the Kickstarter thing because I wanted to avoid potential embarrassment. I eventually got the campaign launched, and it was a success, and Pixy got a chance to see the light of day, so that was good. It was a lot of work, and it was psychologically exhausting, but it was really fun to see folks excited about your idea. I’d totally do it again though, and I’d like to crowdfund my next project.

CIRCUIT CELLAR: Can you tell us about one or two of the more interesting projects you’ve seen featuring Pixy?

RICH: Ben Heck used Pixy in a couple of his episodes of the Ben Heck Show ( He used Pixy to create a camera that can automatically track what he’s filming. And Microsoft used Pixy for an Windows 10 demo that played air hockey IR-Lock ( is a small company that launched a successful Kickstarter campaign that featured Pixy as a beacon detector for use in autonomous drones. All of these projects have a high fun-factor, which I really enjoy seeing.

CIRCUIT CELLAR: What’s next for Charmed Labs?

RICH: I’ll tell you about one of my crazier ideas. My wife gets on my case every holiday season to hang lights on the house. It wouldn’t be that bad, except our next-door neighbors go all-out. They hang lights on every available surface of their house—think Griswolds from the Christmas Vacation movie. So anything I do to our house looks pretty sad by comparison. I’m competitive. But I had the idea that if I created a computer-controlled light show that’s synchronized to music, it might be a good face-saving technology, a way to possibly one-up the neighbors, because that’s what it’s all about, right? (Ha!) So I’ve been working on an easy-to-set-up and low-cost way to make your own holiday light show. It’s way outside of my robotics wheelhouse. I’m learning about high-voltage electronics and UL requirements, and there’s a decent chance it won’t be cost-competitive, or even work, but my hope is to launch a crowdfunding campaign in the next year or so.

CIRCUIT CELLAR: What are your thoughts on the future of open-source hardware?

RICH: We can probably thank the Arduino folks because before they came along, very few were talking about open hardware. They showed that you can fully open-source a design (including the hardware) and still be successful. Pixy was my first open hardware project and I must admit that I was a little nervous moving forward with it, but open hardware principles have definitely helped us. More people are using Pixy because it’s fully open. If you’re interested in licensing your software or firmware, open hardware is an effective marketing strategy, so I don’t think it’s about “giving it all away” as some might assume. That is, you can still offer closed-source licenses to customers that want to use your software, but not open-source their customizations. I’ve always liked the idea of open vs. proprietary, and I’ve learned plenty from fellow engineers who choose to share instead of lock things down. It’s great for innovation.

On a different robot, a flapping winged ornithopter, we had this PC104 computer running matlab as the controller. It probably weighed about 2 pounds, which forced us to build a huge wingspan – almost 6 feet. We dreamed about adding some machine vision to the platform as well. Having just built a vision-based robot for MIT’s MASLAB competition using an FPGA paired with an Arduino – the PC104 solution started to look pretty stupid to me. That was what really got me interested embedded work. FPGAs and Microcontrollers gave you an insane amount of computing power at comparatively minuscule power and weight footprints. And so died the PC104 standard.


This interview appears in Circuit Cellar 305 (December 2015).