How-to Articles

Most control systems utilize feedback in some manner. Here's a look at several fundamental feedback mechanisms, culminating in a description of a basic PID controller.

In 1998, the UK's Motor Industry Software Reliability Association established a set of 127 guidelines for the use of C in safety-critical systems. Here's a look at the rules, what they mean, and how they can work for you.

Sun's K Virtual Machine gives embedded developers a virtual kick in the pants. KVM makes it possible to, for the first time, run Java programs on any 16-bit processor with 128KB of available memory.

Language specifications, including those for C and C++, are often loosely written. A static analysis tool called lint can help you find dangerous and non-portable constructs in your code before your compiler turns them into run-time bugs.

When tasks share resources, as they often do/must, strange things can and will happen. Priority inversions can be particularly difficult to anticipate. A basic understanding of the problem is key.

Memory leaks can be particularly risky for long-running embedded systems. Here are some tools to identify, track, and analyze memory leaks in embedded C and C++ programs.

Some human languages are read and written from left to right; others from right to left. A similar issue arises in the field of computers, involving the representation of numbers.  Which is the most convenient end on your system?

For those embedded systems that can't be constantly watched by a human, watchdog timers may be the solution.

Most embedded systems need to be self-reliant. It's not usually possible to wait for someone to reboot them if the software hangs. Some embedded designs, such as space probes, are simply not accessible to human operators. If their software ever hangs, such systems are permanently disabled. In other cases, the speed with which a human operator might reset the system would be too slow to meet the uptime requirements of the product.

Pulse width modulation (PWM) is a powerful technique for controlling analog circuits with a processor's digital outputs. PWM is employed in a wide variety of applications, ranging from measurement and communications to power control and conversion.

The proper use of C's volatile keyword is poorly understood by many programmers. This is not surprising, as most C texts dismiss volatile in a sentence or two. This article will teach you the proper way to use volatile.

Have you experienced any of the following in your C or C++ embedded code?