Choosing An Ultralow-Power MCU

Mike Mitchell

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

Erik Cheever

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

Tim Wescott

PID (proportional, integral, derivative) control is not as complicated as it sounds. Follow these simple implementation steps for quick results.

Reed-Solomon Error Correction

C.K.P. Clarke

[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

Leslie Aldridge

This 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

Mark Mitchell, Jeffrey Oldham

This book is intended for learning advanced linux programming.

Red Hat Linux - The Complete Reference

Richard Petersen

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

Sreekrishnan Venkateswaran

This 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

Ulrich Drepper

As 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.

Driving I2C-Bus Signals Over Twisted Pair Cables with PCA9605

NXP Semiconductors

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.