Driving I2C-Bus Signals Over Twisted Pair Cables with PCA9605
The availability of powerful I2C buffers that drive their I/Os on both sides to a nominal ground or ‘zero offset’ logic level allows the removal of noise introduced into one section of a larger bus system. That ‘regeneration’ of clean I2C signals enables building long I2C buses by combining together relatively short bus sections, each say less than 20 meters, using such buffers or multiplexers that contain them. Conventional twisted pair communication cabling with its convenient connectors, and a ‘modular’ I2C system approach, make large system assembly easy. Each drop point or node can be individually selected for bidirectional data communication with the Master just by using normal I2C software addressing. As an example, a system is described for control of LED lighting displays and it is suggested that the power for the LEDs, and the I2C control system, might be economically provided using ‘extra low voltage’ distribution at 48 V using either the control signal cable or similar low cost wiring in a manner similar to that used in ‘Power over the Ethernet’ systems. The simplicity and flexibility of this approach makes it attractive to consider as an alternative to other control systems such as RS-485 or CAN bus.
C++ Tutorial
●5 commentsThese tutorials explain the C++ language from its basics up to the newest features of ANSI-C++, including basic concepts such as arrays or classes and advanced concepts such as polymorphism or templates. The tutorial is oriented in a practical way, with working example programs in all sections to start practicing each lesson right away
Arduino Programming Notebook
This notebook serves as a convenient, easy to use programming reference for the command structure and basic syntax of the Arduino microcontroller. To keep it simple, certain exclusions were made that make this a beginner’s reference best used as a secondary source alongside other websites, books, workshops, or classes. This decision has lead to a slight emphasis on using the Arduino for standalone purposes and, for example, excludes the more complex uses of arrays or advanced forms of serial communication.
Introduction to Embedded Systems - A Cyber-Physical Systems Approach
●3 commentsThis book strives to identify and introduce the durable intellectual ideas of embedded systems as a technology and as a subject of study. The emphasis is on modeling, design, and analysis of cyber-physical systems, which integrate computing, networking, and physical processes. This book is intended for students at the advanced undergraduate level or the introductory graduate level, and for practicing engineers and computer scientists who wish to understand the engineering principles of embedded systems.
Embedded Systems – Theory and Design Methodology
●3 commentsThis book addresses a wide spectrum of research topics on embedded systems, including basic researches, theoretical studies, and practical work.
High Performance Systems, Applications and Projects
●1 commentThis book addresses a wide spectrum of research topics of embedded systems, including parallel computing, communication architecture, application-specific systems, and embedded systems projects.
Lessons in Electric Circuits - Volume III - Semiconductor
●2 commentsThis book covers all of the common semiconductor devices and their principles of operation. However, the true value of this reference is in the fact that it provides key circuits and applications where they come in handy. A few of the devices that are covered in this book are Bipolar junction transistors, diodes, JFETs, thyristors, OPAMPs and FETs. This book will be a good reference in your library that has a clear style of explanation.
Embedded Linux Primer
●4 commentsThis book brings together indispensable knowledge for building efficient, high-value, Linux-based embedded products: information that has never been assembled in one place before. Drawing on years of experience as an embedded Linux consultant and field application engineer, Christopher Hallinan offers solutions for the specific technical issues you're most likely to face, demonstrates how to build an effective embedded Linux environment, and shows how to use it as productively as possible.
A Guide to Approximations
Most embedded processors don’t know how to compute trig and other complex functions. Programming in C we’re content to call a library routine that does all of the work for us. Unhappily this optimistic approach often fails in real time systems where size, speed and accuracy are all important issues. The compiler’s runtime package is a one-size-fits-all proposition. It gives a reasonable trade-off of speed and precision. But every embedded system is different, with different requirements. In some cases it makes sense to write our own approximation routines. Why?
Consistent Overhead Byte Stuffing
Byte stuffing is a process that transforms a sequence of data bytes that may contain ‘illegal’ or ‘reserved’ values into a potentially longer sequence that contains no occurrences of those values. The extra length is referred to in this paper as the overhead of the algorithm. To date, byte stuffing algorithms, such as those used by SLIP [RFC1055], PPP [RFC1662] and AX.25 [ARRL84], have been designed to incur low average overhead but have made little effort to minimize worst case overhead. Some increasingly popular network devices, however, care more about the worst case. For example, the transmission time for ISM-band packet radio transmitters is strictly limited by FCC regulation. To adhere to this regulation, the practice is to set the maximum packet size artificially low so that no packet, even after worst case overhead, can exceed the transmission time limit. This paper presents a new byte stuffing algorithm, called Consistent Overhead Byte Stuffing (COBS), that tightly bounds the worst case overhead. It guarantees in the worst case to add no more than one byte in 254 to any packet. Furthermore, the algorithm is computationally cheap, and its average overhead is very competitive with that of existing algorithms.
Embedded Touchscreen Handbook
I want to add a touchscreen to my embedded product. Where do I start? That question is common nowadays. Most manufacturing companies are seeing the value – maybe the necessity – of touch screen technology. Many of them don’t have a long-term or close association with the technology, yet they expect their embedded engineers to handle the project successfully and on a tight schedule. These engineers often have questions... - How much am I going to have to learn to get the job done? - I’ve heard that LCD suppliers were not like other suppliers. But, how so? - What don’t I know that could shift the project from “exciting” to “doomed.” You have choices: Probably the three major questions that crop up when you need to add an LCD touch screen to your product are these: - Should I use a full-blown, embedded operating system, like Windows CE, CE Linux or QNX? - How much work does it take to develop an in-house LCD system from scratch? - Do I have other options? The answer to the first two questions is a resounding “maybe,” (depending on what you need to accomplish). The answer to the third question is, probably “yes.” In most cases, there is another option. Who should read this? If you are an embedded engineer who is thinking of adding a touch screen to your product, and if: - You need to know what is involved in adding color touch controls to your product. -You need to understand the risks (both known and hidden) involved in LCD technology. - Your main area of expertise is not LCD technology. - You don’t want to re-focus your time to acquire color LCD technology expertise. If you find that any of the statements above voice your concerns, you may find this paper worth reading.
Time in Wireless Embedded System
●1 commentWireless embedded networks have matured beyond academic research as industry now considers the advantages of using wireless sensors. With this growth, reliability and real-time demands increase, thus timing becomes more and more relevant. In this dissertation, we focus on the development of highly stable, low-power clock systems for wireless embedded systems. Wireless embedded networks, due to their wire-free nature, present one of the most extreme power budget design challenges in the field of electronics. Improvements in timing can reduce the energy required to operate an embedded network. However, the more accurate a time source is, the more power it consumes. To comprehensively address the time and power problems in wireless embedded systems, this dissertation studies the exploitation of dual-crystal clock architectures to combat effects of temperature induced frequency error and high power consumption of high-frequency clocks. Combining these architectures with the inherent communication capabilities of wireless embedded systems, this dissertation proposes two new technologies; (1) a new time synchronization service that automatically calibrates a local clock to changes in temperature; (2) a high-low frequency timer that allows a duty-cycled embedded system to achieve ultra low-power sleep, while keeping fine granularity time resolution offered only by high power, high frequency clocks.
Stop Guessing – Trace Visualization for RTOS Firmware Debugging
Some decades ago, the embedded industry shifted focus from assembly to C programming. Faster processors and better compilers allowed for raising the level of abstraction in order to improve development productivity and quality. We are now in the middle of a new major shift in firmware development technology. The increasing use of real-time operating systems (RTOS) represents the third generation of embedded software development. By using an RTOS, you introduce a new abstraction level that enables more complex applications, but not without complications.
Transforming 64-Bit Windows to Deliver Software-Only Real-Time Performance
Next-generation industrial, vision, medical and other systems seek to combine highend graphics and rich user interfaces with hard real-time performance, prioritization and precision.Today’s industrial PCs running 64-bit Windows, complemented by a separate scheduler on multicore multiprocessors, can deliver that precise real-time performance on software-defined peripherals.
Electrical Ground Rules Part 3
Best Practices for Grounding Your Electrical Equipment Examining the role of ground as a voltage stabilizer and transient limiter, along with tips on improving safety and signal integrity (Part 3 of 3)
Driving I2C-Bus Signals Over Twisted Pair Cables with PCA9605
The availability of powerful I2C buffers that drive their I/Os on both sides to a nominal ground or ‘zero offset’ logic level allows the removal of noise introduced into one section of a larger bus system. That ‘regeneration’ of clean I2C signals enables building long I2C buses by combining together relatively short bus sections, each say less than 20 meters, using such buffers or multiplexers that contain them. Conventional twisted pair communication cabling with its convenient connectors, and a ‘modular’ I2C system approach, make large system assembly easy. Each drop point or node can be individually selected for bidirectional data communication with the Master just by using normal I2C software addressing. As an example, a system is described for control of LED lighting displays and it is suggested that the power for the LEDs, and the I2C control system, might be economically provided using ‘extra low voltage’ distribution at 48 V using either the control signal cable or similar low cost wiring in a manner similar to that used in ‘Power over the Ethernet’ systems. The simplicity and flexibility of this approach makes it attractive to consider as an alternative to other control systems such as RS-485 or CAN bus.
Arduino Programming Notebook
This notebook serves as a convenient, easy to use programming reference for the command structure and basic syntax of the Arduino microcontroller. To keep it simple, certain exclusions were made that make this a beginner’s reference best used as a secondary source alongside other websites, books, workshops, or classes. This decision has lead to a slight emphasis on using the Arduino for standalone purposes and, for example, excludes the more complex uses of arrays or advanced forms of serial communication.
Consistent Overhead Byte Stuffing
Byte stuffing is a process that transforms a sequence of data bytes that may contain ‘illegal’ or ‘reserved’ values into a potentially longer sequence that contains no occurrences of those values. The extra length is referred to in this paper as the overhead of the algorithm. To date, byte stuffing algorithms, such as those used by SLIP [RFC1055], PPP [RFC1662] and AX.25 [ARRL84], have been designed to incur low average overhead but have made little effort to minimize worst case overhead. Some increasingly popular network devices, however, care more about the worst case. For example, the transmission time for ISM-band packet radio transmitters is strictly limited by FCC regulation. To adhere to this regulation, the practice is to set the maximum packet size artificially low so that no packet, even after worst case overhead, can exceed the transmission time limit. This paper presents a new byte stuffing algorithm, called Consistent Overhead Byte Stuffing (COBS), that tightly bounds the worst case overhead. It guarantees in the worst case to add no more than one byte in 254 to any packet. Furthermore, the algorithm is computationally cheap, and its average overhead is very competitive with that of existing algorithms.
A Multithreaded Real-time Robot for Embedded Design Space Exploration
This thesis introduces an autonomous robot platform for real-time scheduling exper- imentation and benchmark suite to evaluate real-time optimizations and apply modern task scheduling methods. It makes two contributions. First, it presents a reference hardware and software design for a line-following, obstacle-avoiding and maze-solving robot. This robot is based on a small commercially-available product. The software is structured as a multithreaded real- time system for use in evaluating scheduling approaches for cost-sensitive and resource- constrained applications. Second, it provides a detailed design space exploration showing the costs (processor speed and memory) of di erent scheduling approaches (static vs. dynamic and non-preemptive vs. preemptive). It also measures and analyzes each task's timing information and explores the mini- mum microcontroller clock speed under di erent scheduling approaches.
An Embedded Object Approach to Embedded System Development
●1 commentBuilding an embedded system from an idea to a product is a slow and expensive process requiring a lot of expertise. Depending on the developer’s expertise, the required quantity and price level of the final product, and the time and money available for development, the developer can build a device from different granularity of components, ranging from ready-made platforms, kits, and modules to individual components. Generally, solutions requiring less expertise, time and money produce products with higher production costs. The main contribution of this thesis is the EOC (Embedded Object Concept) and Atomi II Framework. EOC utilizes common object-oriented methods used in software by applying them to small electronic modules, which create complete functional entities. The conceptual idea of the embedded objects is implemented with the Atomi II framework, which contains several techniques for making the EOC a commercially feasible implementation. The EOC and the Atomi II Framework decreases the difficulty level of making embedded systems by enabling a use of ready-made modules to build systems. It enables automatic conversion of a device made from such modules into an integrated PCB, lowering production costs compared to other modular approaches. Furthermore, it also enables an automatic production tester generation due to its modularity. These properties lower the number of skills required for building an embedded system and quicken the path from an idea to a commercially applicable device. A developer can also build custom modules of his own if he possesses the required expertise. The test cases demonstrate the Atomi II Framework techniques in real world applications, and demonstrate the capabilities of Atomi objects. According to our test cases and estimations, an Atomi based device becomes approximately 10% more expensive than a device built from individual components, but saves up to 50% time, making it feasible to manufacture up to 10-50k quantities with this approach.
