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A real-life Star Trek communicator for $99 (via OnBeep)

OnBeep is a San Francisco start-up company that recently unveiled its Onyx communicator to technocrats in New York, sparking buzz. OnBeep is only one year old, but they raised $6.25 million in early 2014 to develop their Onyx device: something that lets you communicate with groups of people at the touch of a button.


The working, finished product was only unveiled early last month, but Business Insider, CNN, Forbes, and Wired already have something to say about it. The design is meant to be worn on any type of clothing, handbags, belts, or even put inside your pocket. The ease of talking at the push of a button was inspired by Star Trek, so your LARPing adventures can be fortified by this device for sure.


In practice, the Onyx seems like an expensive, stylish speaker phone in the style of a walkie-talkie. In terms of hardware and design, it basically is exactly that. But the co-founder, Jessie Robbins notes that it does more: it allows a group of people to work together and stay focused on the task at hand. Both Robbins, and the OnBeep CTO, Greg Albrecht, have experience in emergency situations as firefighters and EMTs. Hence, the Onyx really makes sense when you need to communicate real-time with a group of colleagues and can’t afford to waste time messing around with a phone.


The cool thing about the Onyx is that in thoeryit allows you to collaborate with anyone around the world. For now, radio frequency regulations mean that people outside the US can't technically buy the Onyx. Considering the amount of funding OnBeep has raised, it seems like a matter of time before the Onyx is available everywhere. The device can currently be pre-ordered for expected release in December 2014. The current cost of the Onyx is $99 which seems a bit steep for an extension of your smartphone, but I can see how it can be super helpful depending on your job environment.


I can certainly see businesses adopting this technology as a new part of team management: cutting the time and space between employees. Perhaps this is why so many business gurus are interested in the technology since it enables people to work together, real-time, outside of boring meetings.


The Onyx works by using Bluetooth to sync to your smartphone. In order to take advantage of Onyx's capabilities, you must download the OnBeep smartphone app which is currently available for iPhone and Android systems. The Onyx then takes advantage of wireless data/WiFi to contact your networks and stay connected. The app allows you to manage your groups, see who's available, and see where every member of your team is located – if you are worried that Tom forgot the dip, for instance.


You can talk to up to 15 people at once with the Onyx, and you can create as many groups as you like. The platform works regardless of network carrier, however it is only compatible with iPhone and Android at the moment.



See more news at:


Hello Everyone!  Just trying to network a little bit, on my breaks...


So, my team has developed some cool products that are actually being utilized out there in the market.


  • EISS™ Virtual Top Node Server




  • EISSBox - OpenADR 2.0b Certified Virtual End Node



  • EISSClient Software Platform



  • EISSBox Data Logger (for Data Logging / Telemetry Endpoint)





If you're close to the Eatontown, NJ area, we're always looking for Embedded Systems and Raspberry Pi experience on our team - growing pretty fast!  We have some real neat stuff going on.  Definitely let me know if you're interested.


















This article was first issued on embedded beat (Freescale blogs)


A mixed environment system is one where a multicore system runs a combination of a real-time operating system and a feature-rich operating system.  It’s not a new concept, and there are many examples of products in the industry today, particularly in automotive and high-end industrial. These devices are feature-rich and highly user-interactive, but must respond quickly and reliably to system level events that are driving critical operation of the device.


After presenting earlier this month on the topic at ARM TechCon, I was energized to see the level of interest in heterogeneous processing for mixed environment use cases. What’s new is that the underlying hardware architecture for a mixed environment use case, if implemented correctly, can now be used to solve new design challenges like improving energy efficiency of devices that need to stay connected and provide continuous monitoring of environmental inputs. The device itself does not need to be in a high level state of operation because it is essentially just maintaining a network connection (Wi-Fi, Bluetooth, others), processing sensor inputs and is not required to perform heavy processing. But the device must also be able to quickly elevate to a higher state of processing when needed.




What I talked about in my session was the challenge of implementing this type of heterogeneous architecture in a single-chip solution that also provides system flexibility without sacrificing system integrity. System flexibility means that both cores have the ability to access all peripherals and shared memory. This ultimately allows the system to be able to adapt to new application use cases. However, this type of shared bus topology means that both cores now have the ability to access all peripherals and shared memory in the system. So the architecture must provide a way to configure and enforce the safe sharing of system resources.


What is the ultimate benefit of this type of heterogeneous architecture?  A more energy-efficient, system-aware device that can also provide a feature-rich user experience and yet not sacrifice on real-time responsiveness.


Where does Freescale fit in?

Freescale is no stranger to multicore and heterogeneous processing, but earlier this year we announced that this architecture will be coming to the i.MX 6 series with the first applications processor to integrate an ARM® Cortex®- A9 core with an Cortex-M4 core in a single chip design. And, heterogeneous processing will bring new applications and new levels of scalability to the i.MX 6 series which already has a broad footprint and acceptance in the embedded market.

You can see more on the next generation of i.MX 6 series in this short informational video.  (Full product disclosure coming in Q1 2015.)


Amanda McGregor is a product marketer for i.MX applications processors.

This article was first published on embedded beat (Freescale blogs)


Some of the Kinetis MCUs are designed to provide industry-leading new technologies, others are optimized to solve specific problems, while others are just designed to appeal to the biggest number of engineers and please everyone.


What type of Kinetis MCU are you most like?


Take this short Kinetis MCU Personality Quiz to find out!


What type of Kinetis MCU are you.

Kathleen Jachimiak is a Kinetis MCU product marketer.

This article was first published on embedded beat (Freescale blogs)


It’s not just about performance and integration, the ARM Cortex-M4 based Kinetis K Series brings world class low-power modes and a comprehensive set of development tools and software, helping you save precious time and resources.


If you haven’t noticed, the Kinetis portfolio is vast – from general embedded, to ultra-low power, to a wide range of application specific MCUs.  As for the Kinetis K Series, we’ve honed in on general embedded applications.  Need USB? We’ve got that. Ethernet, Crypto? Yep. Graphic LCD? Ditto.  And there’s more.  Kinetis K devices range in flash size from 32KB to 2MB, up to 256KB of onboard SRAM and a broad range of peripheral combinations for measurement and control, connectivity and security.


Selector Guide


Here’s the family lineup:

K0x Entry-level MCUs
K1x Baseline MCUs
K3x Segment LCD MCUs
K4x USB & Segment LCD MCUs
K5x Measurement MCUs
K6x Ethernet Crypto MCUs
K7x Graphic LCD MCUs

How do you decide which device is best for your design with what seems like endless options?

We’ve helped make the selection process easier with the Kinetis K Selector Guide.

Try it out and let me know what you think.


Justin Mortimer is a Kinetis Product Owner

This article was first issued on Freescale embedded beat blogs (http://blogs.freescale.com) by Kathleen Jachimiak, product marketing manager for Kinetis microcontrollers.



Remember playing with Rubik’s cubes back in t he 1980s? 2014 actually marks the 40th birthday of this 3D puzzle. It is a simple cube in which each side is made up of nine colored mini-cubes with an objective to somehow rotate it in exactly the correct way so that each side would be one solid color. They provide hours of fun, but are not always easy to figure out. I read online that with six colored sides, 21 pieces and 54 outer surfaces, there’s a combined total of over 43 quintillion different possible configurations. No wonder I failed to ever solve that thing on my own!


The thought of doing the next great engineering design can be equally daunting. And while Kinetis MCUs cannot help you solve the Rubik’s cube (unless of course you use some sort of cube-solving machine like the one shown here), Kinetis MCUs can help you solve today’s- and tomorrow’s- engineering design challenges with a broad portfolio of ARM®-based solutions. Though not quite a quintillion (yet), Freescale is offering close to 1,000 products for customers to choose from.


The Kinetis MCU portfolio is often referred to as the world’s broadest ARM® Cortex®-M-based portfolio. But, what makes a portfolio broad? And is that even a good thing?

A broad portfolio is about providing choices that span the technical limits in terms of low-end and high-end capabilities, and filling all of the gaps in between. It means offering solutions that can enable everything from a swallowable medical device to the electronics within a 5,000-pound truck. The Kinetis MCU portfolio has both general purpose and application-specific devices designed to do just that – meet the various needs of embedded designers while covering a breadth of options for performance, memory, package, integration and price.

General Purpose vs. Application-Specific Devices


The Kinetis MCU portfolio is most easily explained as six (and counting) series of general purpose and application-specific devices. General purpose series, like Kinetis K and Kinetis L series, reach the greatest number of customers, while application-specific series target vertical markets to provide specific integration and support. Within each series is a number of families that further divide the portfolio into various levels of integration and performance.


Kinetis K series MCUs were our first MCUs based on ARM Cortex-M cores and the industry’s first MCUs based on the ARM-Cortex-M4 core. As well, it is called the K series because that is how it all started – K for Kinetis. These devices are known for pushing high performance and various level of integration supporting the broadest range of customers.

Kinetis L series is our ultra- low power series and the industry’s first Cortex-M0+-based MCU. In fact, this series boasts the world’s most energy-efficient ARM-based MCU. It also holds the record as the world’s smallest ARM-based MCU, thanks to Freescale’s wafer-level chip-scale packaging (WLCSP) technology.

Kinetis E series MCUs are about supporting applications in electrically harsh conditions with high EMI and ESD thresholds. They are designed to maintain high robustness and reliability within electrically noisy environments. And in another first, Kinetis E series MCUs were the industry’s first 5V MCUs built on the ARM Cortex-M0+ processor.

Kinetis V series MCUs are designed for (vector) motor control and digital power conversion applications. This is the most recently introduced series for the Kinetis portfolio, launching in April 2014.

Kinetis M series MCUs are an application-specific series, targeted for metering and measurement applications.

Kinetis W series MCUs are for wireless applications. These Kinetis MCUs are with integrated radio transceivers for 802.15.4 2.4GHz and sub 1-GHz wireless communications.

Scalability and Compatibility: The Secret to Success
It’s not enough to have a lot of parts. To a designer looking for a specific solution, the fact that we have 999 other options is not all that interesting to him/her. The secret to making a broad portfolio successful is scalability and compatibility, and Kinetis MCUs offer both. Providing both pin-to-pin and software compatible options is key for customers wishing to scale up and down the portfolio to address various market segments and tiers of products within those segments. Additionally, Kinetis customers are able to reach faster time to market with common software and hardware tools.


Get more info on the Kinetis MCU portfolio @ Freescale.com/Kinetis


Kathleen Jachimiak is a product marketing manager for Kinetis microcontrollers.

This article was first published on Embedded Beat (oct. 2014) by Donnie Garcia, Freescale Kinetis New Products Team




I don’t have a home security system, but my second hand experience from family and friends is that they can be a real hassle. In addition to the cost of the system and having it physically installed, there are constant headaches with remembering to set the alarm, false alarms, and having to remember yet another password. When deciding to bring such a device into the home, home owners must balance cost and inconvenience with the benefits of peace of mind and crime deterrence. In the embedded world, as more “Things” get connected, a similar choice has to be made: accessibility via connectivity has opened up a new range of “Things” which are vulnerable to attacks. Embedded developers of home automation nodes, energy metering and payment solutions all have to deal with numerous and aggressive threats.


Protecting embedded assets is not a new problem, and for Freescale, a semiconductor company who can provide a solution for virtually all points within the Internet of Things (IoT) continuum, there is a strong legacy of excellence in security. As a Kinetis MCU product marketer, I have had the opportunity to collaborate with security experts from across the company who work on our numerous product lines to ensure that the best possible security is being implemented in our embedded solutions. Kinetis MCUs contain features to help improve reliance of end applications and have a type of embedded trust architecture that can be used to provide security in the age of increasing connectedness.

Kinetis devices provide an advantage that most other higher end applications processors do not typically have. Kinetis MCUs are architected to only boot up from internal memory.  This protects against the threat of hijacking an embedded application by changing an external memory device.

In addition, Kinetis devices have several levels of embedded protection that can be selected using non-volatile control bits. The protection, when enabled, restricts access to all internal resources (Flash, SRAM and peripheral registers) from the debug port. As well, to facilitate a safe firmware update via a serial peripheral, Kinetis devices have a 64-bit key, which can be set so that only authorized firmware updates are allowed.


The highest levels of Kinetis security can also lock the embedded memory by disabling Flash erase capabilities, forever locking the application code in the end device. This security level creates a secure ‘Read Only Memory’ version of the embedded application, essentially avoiding the threat of cloning of a device.

Some Kinetis devices have an additional external memory interface (for SRAM or NOR Flash). On these devices, when security is enabled, the attributes of this external memory are controlled by system level configuration bits. So, even in higher end embedded applications which rely on external memory expansion, the reliable Kinetis MCU security architecture has the capability of restricting execution from the external memory to protect against attacks.

Many Kinetis devices also contain a system level Memory Protection Unit (MPU). This peripheral can be used to define memory spaces with certain access rights, creating another layer of system checking to ensure that the execution of firmware is controlled.


Besides the standard features mentioned above, cryptographic acceleration hardware is available on a number of Kinetis sub-families. This hardware, which is enabled by a library, greatly speeds up cryptographic algorithms that can be used in firmware updates or in the protection of data as it passes from device to device.

On a sub-set of Kinetis devices there are advanced anti-tamper capabilities. The features of this peripheral include a tamper protected memory space for a master key. The security of a system depends on keeping the master key a secret. The tamper protected memory space is automatically erased if a tamper event is detected. This erasure of the master key happens without any software intervention, and so can be depended upon to protect the most sensitive data. Tamper events are not only physical attacks, and so the advanced security peripheral also protects against temperature, voltage or clock speed attacks.


One of the newest features on the Kinetis devices is the Flash Access Control (FAC). This feature was made to support the growing need of protection of software intellectual property (for example, proprietary sensor algorithms, or connectivity stacks). The FAC allows the use of software libraries while not allowing them to be read or downloaded from the device. This feature works in conjunction with the embedded security levels of the Kinetis MCUs to provide developers a platform to use to promote their innovations in a safe and reliable way. Being able to protect software property will be a key enabler to the propagation of embedded technology expected by the Internet of Things.

What will the future bring in regards to embedded security features? To support the expansion of Kinetis edge nodes, more advanced encryption acceleration and new algorithms are on the roadmap.


Finally, as a product definer, I am always looking for new requirements. What aspect of embedded security threat are you concerned with? Leave a comment.


Donnie Garcia is on the Kinetis New Products Team

For those familiar with TrueSTUDIO from Atollic, you already know how powerful this development environment is, and what it offers beyond the C/C++ compiler and debugger functionality.  For all the rest please check out more about it in element 14 Design Center and see the intro video here.


element14 is now selling TrueSTUDIO for your and your business' needs in the Americas.


Blueshift Hydrogen (via Blueshift)


If you thought the ‘80s mobile boombox was out of style, guess again. Blueshift recently announced the launch of its portable, supercapacitor-powered, Bluetooth speaker, Hydrogen – your new best friend.


The Blueshift Hydrogen speaker is changing the nature of mobile devices. The portable Bluetooth speaker is powered by supercapacitors, and while it only takes five minutes to fully charge, the 4lb speaker can play for more than 4 hours at 80 percent volume. Connect it to your computer, cell phone, or any other Bluetooth-capable device and let the beat drop.



Inside the Hydrogen speaker (via Blueshift)


Blueshift’s Hydrogen sits at 9” x 8” x 4.” What it lacks in stature it makes up for in sound. The beach-friendly box speaker features a 3” full-range driver, Class-D amplifier and volume controls, housed in a bamboo shell – a wood which really vibrates well for music., All of the speaker’s parts are custom-made in America and the entire unit is plastic-free. The real secret, however, are the supercapacitors.


While batteries store chemical energy, supercapacitors house energy in the form of a physical, electric field. This allows for the technology to charge rapidly and remain extremely durable. For example, the supercapacitors that power the Hydrogen speaker charge in five minutes and are guaranteed to function at optimal energy levels for up to half a million charges. If the same technology is applied to mobile devices everywhere (or any electronic devices, for that matter), your local energy company would be very upset.


The Hydrogen speaker is open-source and includes a Bluetooth A2DP and 1/8” wired input, 1/8” cable and AC charger in the box. Blueshift claims that the Hydrogen speaker is built to last. All of the parts are easily replaceable and/or upgradeable and all of the parts, from the components to the bamboo shell itself, are durable. With this, since the project is open-source, Blueshift welcomes new upgrades and enhancements from consumers. While supercapacitors are still more expensive than traditional batteries, having a practical way to use the technology really opens the doors for makers to change the way we charge. 

Blueshift has designed a number of other speakers, currently on presale via Crowd Supply, including a subwoofer, entitled Iron Subwoofer, preamp and home sound system. All of the speakers feature bamboo and the signature Blueshift simplistic design. While the designs are open hardware, the retail versions are proprietary.



Blueshift Product Line (via Blueshift)


Blueshift is currently running a crowd-funding campaign via Crowd Supply. The Hydrogen speaker will retail for $400, but is on sale for early backers at $330. All of the company’s speakers are on presale, but the Hydrogen may be the best bang for your buck. Cool Material was quoted saying that the portable speaker might be the best deal in the market, when factoring charge time vs. playback.


The crowd funding campaign is open for two more weeks, so if you’re considering buying one, act now. Honestly, who couldn’t use a portable speaker? So, hurry and support their effort!

Sure, they’re wonderfully useful at morning board meetings, but they’re epically awesome on the beach. C’mon man. Drop that bass.


See more news at:


Dear Microcontroller and Microprocessor users


1. You are looking for some training to learn programming your RiOTboard (i.MX6 ARM Cortex-A9) or your Freedom board (Kinetis ARM Cortex-M0+/M4) ?

2. You are able to come to Paris, France to visit us at the Freescale DWF event scheduled October 14th 2014 in the famous Roland Garros tennis stadium ?

Farnell/Element14 will drive a technical hands-on for RiOT board and teach you step-by-step, how to create a webserver demo featuring a temperature sensor datalogger, which a nice IoT example.

During this 3h lab, you will learn how to copy a BSP image, generate a Linux BSP image with the Yocto builder tool and you will start creating the application based on Linux 3.10.

Computer and boards will be provided during the workshop session.

Freescale will drive a hands-on for Freedom board (FRDM-K64F) and teach you step-by-step how to create a sensing application which is another nice IoT peripheral example.

During this 3h lab, you will learn how to create from scratch a project using new Freescale development tools Kinetis Design Studio (IDE toolchain) and Kinetis Software Development Kit (peripheral libraries). 

Computer and boards will be provided during the workshop session.

All Freescale experts and several 3rd parties will be present to answer your questions.

More than 45 application demos will be exposed in the 620m² Techlab based on latest Freescale technologies (ARM Cortex-M Microcontrollers, ARM Cortex-A Processors, Motion Sensors, Radio, Analog).

And the best for the end ... This is a 100% free event including lunch and drinks.

I have posted below the official invitation and the link to register (please select Farnell as distributor for our invitation statistics).

Don't hesitate to answer this blog if you have some questions.

Nice to meet you there


Sans titre 1.jpg

Designing with Freescale Seminar, Paris Roland Garros, 14 Octobre 2014

Freescale a le plaisir de vous inviter à son événement technologique phare de l’année.

Ne manquez pas cette occasion de participer à notre journée de présentations et de formations portant sur nos technologies, produits et solutions pour l’électronique embarquée.

Designing with Freescale (DwF) offre des sessions interactives sur une large gamme de solutions Freescale pour les ingénieurs développant des produits et systèmes innovants.


Lors de cette journée, vous pourrez découvrir et participer à :


- Des sessions techniques présentant nos différentes familles de produits : microcontrôleurs et microprocesseurs basés sur les architectures ARM® et Power Architecture®,

capteurs, circuits analogiques, connectivité couvrant les marchés automobile, industriel, grand public et réseaux.


- Un Techlab de 620m²où seront exposées plus de 45 démonstrations d’applications mises en œuvre par Freescale et ses partenaires.


- Une formation ‘’hands-on’’ pour créer votre première application dans le monde de l’Internet des Objets (IOT).Grace à la carte communautaire  RIoT,

vous testerez toute la puissance de son processeur ARM®  i.MX 6Solo. Ses accessoires vous montreront comment il est rapide de

développer cette application sous un Operating Système Linux ou Android et connectée au ‘’Cloud’’.


- Une formation ‘’hands-on’’ sur les capteurs basée sur la plateforme de développement Freescale Freedom. Vous découvrirez notre outil de développement

de logiciels pour les capteurs Xtrinsic sensing solutions et comment  programmer le code dans un microcontrôleur de la série Kinetis.


- Une table ronde sur l’Internet des Objets avec des experts dans les domaines des plateformes logicielles, de la sécurité des systèmes ainsi que de la connectivité.


Si vous êtes intéressé par cette opportunité unique, cliquez sur le lien ci-dessous pour découvrir l’agenda détaillé et vous enregistrer.


En savoir plus et s’enregistrer>>


PCB stack-up design

Posted by skipbruce Aug 21, 2014
PCB Stack-Up Design

Before designing multi-layer PCB circuit boards, designers need to confirm the circuit boards structure primarily based on the scale of circuit, the size of circuit boards, and the requirements of electromagnetic compatibility (EMC). It means that designers have to decide to use 2, 4, 6, or more layers of circuit boards. If the design requires the use of high density ball grid array (BGA) devices, the minimal number of wiring layers required for these devices must be considered. For years, people always believe that the less PCB layers, the lower the cost, however, there are many other factors affecting PCB manufacturing costs. In recent years, the differences between costs of multi-layer boards have been reduced significantly. As soon as the number of layers been determined, the placement of the inner layer and how to distribute different signals in these layers can then be decided --- this is the stack-up design of multi-layer PCB. Careful planning and choosing rational stack-up designs beforehand will save a lot of efforts in the following wiring and future production.


1.1 Layer Selection Principle

There are many factors to consider when determining the number of layers of multi-layer PCB board. For experienced designers, they will emphasize on the analysis of the bottlenecks of PCB wiring after the pre-placement of devices. In combination with other EDA tools to analyze wiring density of circuit board; and combined with the quantities and kinds of signal lines with specific wiring demands, such as differential lines, sensitive signal lines, to determine the number of signal layers; and then to determine the number of internal power layer according to the type of power supply, isolation and immunity requirements. Therefore, the layer number of the whole circuit board plates is basically determined.

The following table is the empirical data to determine number of signal layers based on the PIN density, for reference.

Ps: Definition of PIN density: Area of board (square inch)/ (Total number of pins on the Board/14)


1.2 PCB Stack-Up Principle

After the number of circuit board layers determined, the following job is to reasonably arrange the placement order of the circuit of each layer. In this part, there are two main factors to be considered:

(1) The distribution of special signal layers

(2) The distribution of power layer and ground layer

The more layers of circuit boards, the more varieties of arrangement of special signal layers, ground layers and power layers, thus it is more difficult to choose the best combination method, but the general principles are as follows.

(1) The signal layer should be next to an internal power layer (internal power/ground layer), shielded by the copper film of internal power layer.

(2) The internal power layer should be integrated with ground layer tightly, which means the thickness of medium between internal power layer and ground layer should take the smaller value, in order to improve the power supply capacitor between the internal power layer and ground layer, and increase the resonant frequency. If the electric potential difference between internal power layer and ground layer is not significant, a smaller insulation thickness can be used, like 5mil (0.127mm).

(3) To avoid the two signal layers directly adjacent. It is easy to introduce crosstalk between adjacent signal layers, leading to the fail of the circuit. To place a ground layer between two signal layers can avoid cross talk efficiently.

(4) Multiple grounded internal power layers can reduce the ground impedance effectively. For example, A signal layer and B signal layer use ground plane respectively can reduce common-mode interference effectively.

(5) The symmetry of layer structure.


1.3 Demonstration

For your reference, a stack-up design for the four, six, and eight layered high speed digital signal PCB is demonstrated in below:

1.3.1 Four Layer Stack–Up

Figure 1.3.1 Four Layer PCB Stack-Up Example

The high speed signals on the top layer are referenced to the ground plane on layer 2. Since the references for the high speed signals on the bottom layer are the power planes on layer 3, it is necessary to place stitching capacitors between the aforementioned power planes and ground. In this stack up, it is preferential to route high speed signals on the top layer as opposed to the bottom layer so that the signals have a direct reference to the ground layer. For some designs it may be desirable to have the bottom layer as primary high speed routing layer. In this case, the power and ground usage on Layer 2 and 3 could be swapped.

1.3.2 Six Layer Stack-Up


Figure 1.3.2 Six Layer PCB Stack-Up Example

In this example, the reference planes for the high speed signals on the top layer are the power planes on layer 2. Stitching capacitors from the associated reference power plane to ground are therefore required. The signal reference for the bottom layer is the ground plane on layer 5. In this stack-up, it is preferable to route high speed signals on the bottom layer. As in the previous example, power and ground layers could be swapped if it is desirable to have the primary high speed routing layer on the top layer.

The reference planes for signals on layer 3 are located on layer 2 and 5. The same reference planes are used by signals routed on layer 4. As the reference planes are on layers which have a relatively large distance from signal layers 3 and 4, the traces would need to be very wide in order to achieve a common impedance of 50Ω. Therefore, these layers are not suitable for routing high speed signals. In this stack-up approach, layers 3 and 4 can only be used for routing low speed signals where impedance matching is not required.

1.3.3 Eight Layer Stack-Up

Figure 1.3.3 Eight Layer PCB Stack-Up Example

The signals on the top layer are referenced to the plane in layer 2, while the signals on the bottom layer are referenced to layer 7. The reference planes for signal layer 3 are the ground plane on layer 2 and the power planes on layer 4. When routing high speed signals on layer 3, stitching capacitors need to be placed between the power and the ground planes. The power planes on layer 5 and 7 are used as references for the high speed signals routed on layer 6.

The inner layer 6 with the two adjacent ground planes is the best choice for routing high speed signals which have the most critical impedance control requirements. The inner layers cause less EMC problems as they are capsulated by the adjacent ground planes. As layer 3 is referenced to a power plane, outer layer 1 and 8 are preferable for high speed routing if layer 6 is already occupied.


Embedded Systems

Posted by em_strings Aug 21, 2014

Hi ,


Embedded Strings inc  is a well-established company which specializes in the design, development, testing and manufacturing of complex embedded systems/Hardware. Our target markets are healthcare, telecommunication, aerospace and remote monitoring.

We have delivered customized hardware and software products that have application in wireless sensor networking, wireless tracking, digital signal processing and innovate medical monitoring devices.

We specialize in Field Programmable Gate Array design , we have developed our own VHDL/Verilog ip cores that have been integrated in high performance embedded systems, Nios SOC , ARM SOC and Digital Signal Processing.

We also have in-house resource to design multi-layer PCB using leading edge design tool Altium.

Please feel free to contact us in case you need to utilize any of the services that our company provides. We guarantee you complete security and confidentiality of information that you will share with us.



Thanking you ,

Ahmed Asim Ghouri

Embedded Strings inc

Website : www.emstrings.com

Email : support@emstrings.com

A Sensing node consists of methane gas sensor, carbon monoxide gas sensor, accelerometer sensor, temperature sensor and RS232 interface circuit with dual port RAM. Methane gas sensor and carbon monoxide gas sensors are placed on stationary node because its concentration is lighter than so it detects near the roof of the mine. The purpose of using accelerometer is to detect the earth quake type of activities. The Sensing node gets data from neighbouring Sensing node and sends its data to the next Sensing node.


The main computing microcontroller in this Hardware is CC430F6137. There are various gas sensors connected to Sensing node which will help monitor explosive and toxic gases within the mine environment. To monitor any structural change in the mine the Sensing node will analyze accelerometer data and to prevent any fire it will also monitor temperature inside the mine.





There are number of sensors connected to the microcontroller as shown in figure 5.The data of some of these sensors will be captured by built-in 12 bit ADC inside the CC430f6137.To extend the addressable memory an external SRAM has been connected via SPI interface whereas Accelerometer is connected via I2C bus.


Schematic Design


The complete schematic design of Sensing node comprises of 3 sheets which are connected with each other using off sheet connectors. The first sheet has a main computing unit of CC430 with CO sensor circuit, Methane gas sensor, Accelerometer and battery monitoring circuit. The second sheet has a RF matching circuit for CC430 RF Radio Core and the 3rd sheet has a power supply circuit for power-up all the modules.




schematic design of Sensing node. The gas sensor output is connected to the voltage clipping circuit because the A/D of CC430 can read maximum of 3.3V and gas sensors output varies from 0V-5V.The Output of clipping circuit is connected to CC430  via A/D convertor. The A/D reads the output of Methane and CO gas sensor and translates its voltage level to the respective gas concentration. The Accelerometer is connected to CC430 via I2C interface. The battery monitoring circuit output is connected to A/D of CC430. A/D read the value of voltage from battery monitoring circuit and displays the status of the battery on respective LED. A 1Kbit of SRAM is included to stationary node due to insufficient internal memory of CC430.






Following is the power supply circuit diagram supplying +3.3V and +5.0V




During testing we were able to send and receive data at a distance of 100 meters with RF power output of +12dbm


Embedded Strings inc  is a well-established company which specializes in the design, development, testing and manufacturing of complex embedded systems/Hardware. Our target markets are healthcare, telecommunication, aerospace and remote monitoring.

We have delivered customized hardware and software products that have application in wireless sensor networking, wireless tracking, digital signal processing and innovate medical monitoring devices.

We specialize in Field Programmable Gate Array design , we have developed our own VHDL/Verilog ip cores that have been integrated in high performance embedded systems, Nios SOC , ARM SOC and Digital Signal Processing.

Please feel free to contact us in case you need to utilize any of the services that our company provides. We guarantee you complete security and confidentiality of information that you will share with us.



Thanking you ,

Ahmed Asim Ghouri

Embedded Strings inc

Website : www.emstrings.com

Email : support@emstrings.com


PCB Panel Design

Posted by skipbruce Aug 18, 2014

1.5 Printed Cuicuit Board Panel Design

There are two problems to consider when design panel: one is how to place the boards; and the other is the way of connection.

1.5.1  Panel Layout

Panel can increase productivity and save on production costs; the first thing to consider in panel design is how to place small plates together to make a lager board. It is recommended that the basis of panel design is when the final size is close to the ideal size (Figure1.2.1). PCB board’s long side length ≥ 125mm

When PCB board’s long side length ≥ 125mm, the boards can be placed as Figure shows. The perfect number of boards is achieved when the final size is consistent with as (Figure1.2.1) requires. The stiffness of this placement is beneficial for the wave-soldering. Figure is a typical panel, and Figure is suitable for the situation that the rounded corners required after the separation of daughter boards.

(a) V-shaped groove separating method


(b) Slotted hole separating method

Figure Panel PCB Board’s long side length < 125mm
When PCB board’s long side length < 125mm, the boards can be placed as Figure shows. The perfect number of boards is achieved when the final board length is consistent with as Figure1.2.1 requires. When this method is used, the rigidity of boards should be concerned. Figure (a) is a typical V - shaped groove separated panel, there are three perpendicular craft edges to the PCB transfer direction with double-sided deposited copper foil, to enhance the stiffness. Figure (b) is suitable for the situation that the rounded corners required after the separation of daughter boards, and the joint stiffness of separated sides paralleled to the PCB transfer direction should be concerned.


(a)V-shaped groove separating method

(b) The Long Slot plus a Small Circular Hole Separating Method


Figure Panel Panel of Sketch Plate

Pay attention to the connection between panel and panel, and try to keep each separated connection in a line, as shows.

(a) L Shaped Panel

(b) T Shaped Panel

Figure Panel of Sketch Plate

1.5.2 Connection of Panel

There are two main connection methods for panel: Double face carved V-shaped groove (V-CUT), and the long slot plus a small circular hole (commonly known as stamp hole), depending on the shape of the PCB. V-CUT connection method

When it is straight-lined connection between plate and plate, the plate margin is neat and does not affect devices installation; the V-CUT method can be used. V-CUT is a through type, and cannot turn in the middle. Currently SMT Board is widely used, characterized with neat and level edges after separation and low processing costs, which is recommended as priority.

a) The two sides of V-CUT line (A side and B side) require a no device and no wire area that is not smaller than 1mm, to avoid the damage to devices and wires when separating.

b) After cutting the V-shaped groove, the remaining thickness X should be 1/4 to 1/3 of the board thickness Y, which is not smaller than 0.4mm. Board bears heavier can take upper limit, and vice versa. The misalignment of the upper and lower sides cut S of V-shaped groove must be less than 0.1mm.

The design requires being consistent with Figure

Figure Design Requirements of V-Cut The Long Slot plus a Small Circular Hole Connection Method

The connection method of long slot plus a small circular hole, also known as stamp hole method, is suitable for any shapes of daughter boards. As the margin area is not neat and level after separation, it is not recommended for those PCB with fixed conduit ferrule.

Requirements for the long slot plus a small circular hole method: The width of long slot is usually between 1.6mm and 3.0mm, and the length is about 25mm to 80mm, the connection bridge between slot and slot is generally 5mm to 7mm, with several small circular holes placed, and the diameter Ф of these holes is 0.8mm ~1 mm, the distance from the center of the aperture to the outside is 0.4mm – 0.5mm: Thicker boards take smaller value and thinner boards take larger value, it is a typical value in Figure The length of the cutting groove is based on the PCB routing directions, assembly process, and the size of PCB. The smaller the aperture, the neater the margin area.

Figure The Long Slot plus a Small Circular Hole Method The Design of Connection Bridge

When design connection bridge, it is mainly to consider: whether the margin area after separation is neat or not; whether it is convenient to separate or not; is the stiffness enough for production; the material, thickness and total weight of single plate; the distance between connection bridges (the recommended distance is 60mm). In order to make the margin area neat after separation, the separating holes are usually placed on the sidelines or slightly within the daughter board.

In PCB (Printed Circuit Board) design, it is best not to exceed the batch-production technology level of manufacturers. Otherwise, the PCBs may not be able to be processed, or have high associated costs.

1.1 Range of Dimensions

The ideal dimensions for production are as follows: width (200mm-250mm), length (250mm-350mm). For a PCB with length shorter than 125mm or width shorter than 100mm the panelization method can be used to transform the dimensions of the PCB to ideal values according to requirements of production. This facilitates component insertion and soldering.

1.2 Shape

a) The shape of the PCB is rectangular. If a PCB does not need a panel, the four corners of the plate must be rounded as shown in Figure 1.2.1. If a panel is needed, the four corners of the PCB must be rounded after being panelized, with radius 1mm-2mm.

Schematic Diagram of PCB Shape

Figure 1.2.1 Schematic Diagram of PCB Shape

To ensure stability in the transmission process, the penalization method is used to transform irregularly shaped PCBs. Specifically, the gap on the corner must be supplemented, as shown in Figure 1.2.2. Otherwise, special tooling design is needed.

Schematic Diagram of Technological Panelization

Figure 1.2.2 Schematic Diagram of Technological Panelization

b) To ensure that the PCB is stably transferred by chains, any gap on a pure SMT must have length shorter than 1/3 of the corresponding edge, as show in Figure 1.2.3.


Permitted Size of Gap

Figure 1.2.3 Permitted Size of Gap

c) Figure 1.2.4 shows design requirements for gold fingers: chamfers are designed on the insertion edge as required; (1-1.5) x 45o chamfers or (R1-R1.5) circular beads should be designed on the two sides of the insertion board to facilitate insertion.

Design of Chamfer of Gold Fingers

Figure 1.2.4 Design of Chamfer of Gold Fingers


1.3 Technology Edge

For a PCB without a technology edge, scopes that are 5mm or further than 5mm from the positive or negative edges of the board cannot have any components or soldering spots; and the wiring position must be at least 3mm from edges of the board. If short-insertion wave soldering is adopted, the board must meet the width requirements of general transfer edges, and the height of components 10 mm from board edges must be limited to 40 mm (containing the thickness of the board), in consideration of the characteristics of short-insertion wave braziers, as shown in Figure 1.3.1.


Schematic Diagram of PCB Transfer Edge

Figure 1.3.1 Schematic Diagram of PCB Transfer Edge

If the size of the keep-out area on the transfer edge of the PCB board cannot meet above-stated requirements, a 5mm or wider processed edge must be added to the corresponding board edge. The smoothing radius of the processed edge is 2mm, as shown in Figure 1.3.2.

Design Requirement 1 of PCB Technology Edge

Figure 1.3.2 Design Requirement 1 of PCB Technology Edge

To meet the special requirements of structural design, if a component protrudes from the transfer edge of the PCB, the width of the auxiliary edge must meet the requirements shown in Figure 1.3.3.

Design Requirement 2 of PCB Technology Edge

Figure 1.3.3 Design Requirement 2 of PCB Technology Edge

1.4 Fiducial Mark

Fiducial marks are needed for the placement of equipment adopting optical locations. They are used for overall automatic location of chip mounters, and must have high contrast ratios when illuminated by a chip mounter.

1.4.1 Design of Fiducial Marks

Requirements of appearance design of fiducial marks are as follows:

1. Solid circle;

2. Inner diameter = 1mm;

3. Ring-shaped radius of the solder mask is 0.5mm, as shown in Figure 1.4.1.

Schematic Diagram of Fiducial Mark

Figure 1.4.1 Schematic Diagram of Fiducial Mark

1.4.2 Application of Fiducial Marks

Fiducial marks are mainly applied to panel, plate and local positions, as shown in Figure 1.4.2.

Application of Fiducial Mark

Figure 1.4.2 Application of Fiducial Marks Global Fiducials

Three fiducials must be selected from the four corners of the board. If both the surfaces of the board have placement components, each surface must have fiducial mark, as shown in Figure 1.4.3.

Location of Fiducial Mark on the Plate

Figure 1.4.3 Location of Fiducial Mark on the Plate Panel Fiducials

Global fiducial marks of three panels are required. The diagonal point of each panel should have at least two fiducial marks. In special situations, you must negotiate with technologists to determine whether the two fiducial marks on two panels can be omitted or not. However, the global fiducial marks of the panels must be reserved. Local Fiducials

The lead pin pitch is smaller than 0.4mm. For QFP packaging chips with more than 144 lead pins, two marks at opposite corners of the chip need to be increased. If the above-stated components are close (with distances smaller than 100mm), they can be regarded as a whole, and two local fiducials need to be increased on the diagonal position, as shown in Figure 1.4.4.

Local Position of Fiducial Marks

Figure 1.4.4 Local Position of Fiducial Marks

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