An Engineer's Guide to the LPC2100 Series
●7 commentsThis book is intended as a hands-on guide for anyone planning to use the Philips LPC2000 family of microcontrollers in a new design. It is laid out both as a reference book and as a tutorial. It is assumed that you have some experience in programming microcontrollers for embedded systems and are familiar with the C language. The bulk of technical information is spread over the first four chapters, which should be read in order if you are completely new to the LPC2000 and the ARM7 CPU.
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.
PID Without a PhD
●8 commentsPID (proportional, integral, derivative) control is not as complicated as it sounds. Follow these simple implementation steps for quick results.
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.
Memory allocation in C
●5 commentsThis article is about dynamic memory allocation in C in the context of embedded programming. It describes the process of dynamically allocating memory with visual aids. The article concludes with a practical data communications switch example which includes a sample code in C.
Advanced Linux Programming
●6 commentsThis book is intended for learning advanced linux programming.
Red Hat Linux - The Complete Reference
This book identifies seven major Linux topics: basic setup, environments and applications, the Internet, servers, administration, and network administration. These topics are integrated into the different ways Red Hat presents its distribution: as a desktop workstation, network workstation, server, and development platform
Essential Linux Device Drivers
●5 commentsThis book is about writing Linux device drivers. It covers the design and development of major device classes supported by the kernel, including those I missed during my Linux-on-Watch days. The discussion of each driver family starts by looking at the corresponding technology, moves on to develop a practical example, and ends by looking at relevant kernel source files. Before foraying into the world of device drivers, however, this book introduces you to the kernel and discusses the important features of 2.6 Linux, emphasizing those portions that are of special interest to device driver writers.
CPU Memory - What Every Programmer Should Know About Memory
●6 commentsAs CPU cores become both faster and more numerous, the limiting factor for most programs is now, and will be for some time, memory access. Hardware designers have come up with ever more sophisticated memory handling and acceleration techniques–such as CPU caches–but these cannot work optimally without some help from the programmer. Unfortunately, neither the structure nor the cost of using the memory subsystem of a computer or the caches on CPUs is well understood by most programmers. This paper explains the structure of memory subsystems in use on modern commodity hardware, illustrating why CPU caches were developed, how they work, and what programs should do to achieve optimal performance by utilizing them.
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.
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.
Enhanced Sample Rate Mode Measurement Precision
The low-noise system architecture and the tailored frequency response employed in the HDO4000A, HDO6000A, HDO8000A and MDA800A series provides the foundation for enhancing ADC sample rates through additional techniques. In this case, carefully constructed filters combined with a pristine front-end amplifier and a frequency response carefully limited to 1 GHz provide the opportunity to provide more measurement precision than would otherwise be possible. The technique utilized to achieve higher measurement precision is interpolation, and this technique is used by default as an Enhanced Sample Rate up to 10 GS/s. By integrating the Enhanced Sample Rate functionality with the normal Timebase controls for Sample Rate, Time and Acquisition Memory adjustment, the oscilloscopes are optimized for best waveform signal fidelity in all situations.
Electrical Ground Rules Part 1
Best Practices for Grounding Your Electrical Equipment A look at circuit grounding and its importance to you, as well as the US AC power system and its use of earth ground (Part 1 of 3)
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.
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.
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?
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.
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)
