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
These 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
This 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
This 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
This 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
This 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
This 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 Linux Primer
This 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.
Design and Implementation of the lwIP Stack
LwIP is an implementation of the TCP/IP protocol stack. The focus of the lwIP stack is to reduce memory usage and code size, making lwIP suitable for use in small clients with very limited resources such as embedded systems. In order to reduce processing and memory demands, lwIP uses a tailor made API that does not require any data copying. This report describes the design and implementation of lwIP. The algorithms and data struc- tures used both in the protocol implementations and in the sub systems such as the memory and bu®er management systems are described. Also included in this report is a reference manual for the lwIP API and some code examples of using lwIP.
An Embedded Object Approach to Embedded System Development
Building 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.
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)
Electrical Ground Rules Part 2
Best Practices for Grounding Your Electrical Equipment Examining our use of ground as protection, and how ground fault circuit interrupter devices operate to protect us from severe shock (Part 2 of 3)
Freescale Trust Computing and Security in the Smart Grid
With the increasing deployment of automated technical solutions in the implementation of automated metering reading (AMR), advanced metering infrastructure (AMI) and smart grid infrastructure, possibilities of security attacks like data hacking, introducing malware in the system and cyber attacks are on the rise as well. Vulnerabilities in AMI devices include non-secure data buses, serial connections or remote access to debug port. The question arises: how can data security and customer privacy in smart meters and smart energy gateways be ensured? This paper talks about how trusted computing helps resolve security issues in implementing the smart grid by providing a clear idea of what elements of the system are trusted—and to what level and why. Freescale solutions that embed trusted computing are also covered.
Choosing An Ultralow-Power MCU
This application report describes how to compare ultralow-power MCUs. It discusses the key differences between popular low-power MCUs and how to interpret features and specifications and apply them to application requirements
Interrupts, Low Power Modes and Timer A
This document contains a lot of what you need to know to get the most out of the MSP430. The MSP430 line is renowned for it's low power usage, and to really utilize it well you have to architect your software to be an interrupt driven device that utilizes the low power modes.
Reed-Solomon Error Correction
[Best paper on Reed-Solomon error correction I have ever read -- and it's from the BBC!] Reed-Solomon error correction has several applications in broadcasting,in particular forming part of the specification for the ETSI digital terrestrial television standard, known as DVB-T. Hardware implementations of coders and decoders for Reed-Solomon error correction are complicated and require some knowledge of the theory of Galois fields on which they are based. This note describes the underlying mathematics and the algorithms used for coding and decoding,with particular emphasis on their realisation in logic circuits. Worked examples are provided to illustrate the processes involved.
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?
