FPGA Development Board

In sharp contrast with plummeting prices of FPGA chips, suitable development systems for these interesting devices are costly and hard to find. However, that situation seems to have changed for the better with the arrival of a low-cost kit from Australia-based BurchEd.The FPGA (Field Programmable Gate Array) is a programmable logic building block for use in complex digital circuits. Using either a hardware descriptive language or a graphics editor, users of FPGAs are able to design logic circuits that can be downloaded into an FPGA chip. The result (hopefully) is the FPGA acting as the desired logic configuration in all its complexity. As may be expected, FPGAs contain a massive amount of universal elements consisting of gates and/or flip-flops, depending on the FPGA chip you have selected for the job. These elements may be interconnected to form configurations, hence the ability of an FPGA to perform countless digital functions designed by you, the user.

Alongside a wide variety of expensive, up-market products, two reasonably powerful C compilers for microcontrollers have emerged in the freeware circuit.The use of ‘free’ C compilers often presents unexpected problems because of the frequent lack of a user-friendly user interface. Also, despite their unrivalled price/performance ratio, these programs deter many potential users because their configuration and setup is not without problems. This article aims at providing some information to help overcome such initial problems. Specifically, we hope to supply some practical guidance in relation to the ‘SDCC’ compiler for the MCS-51 series and ‘AVRGCC’ for Atmel micros.

Many people are put off using Digital Signal Processors (DSPs) by the thought of grappling with complex mathematical algorithms. In some situations a DSP offers the most cost-effective solution and in practice you don’t need to be Einstein to use them successfully. In this article we deal with a practical application and take a look at some of the background theory.Back in March 1998 we published a series of articles titled “Introduction to digital signal processing” which gave a good insight into the theory behind signal processing and used software routines running on a PC and its sound card to process signals. This article takes a different slant. Here we take a proprietary DSP chip (just a special form of high-speed processor using an instruction set that allows mathematical computations to be performed efficiently) and together with the author’s filter design software we build a practical filter circuit.

GPS modules with NMEA output are available for less than 80 pounds, and compact hand-held GPS units with the interface are now hardly any more expensive. This article shows what can now be done with these units.The Global Positioning System (GPS) allows the user to determine very accurately his position in space. Since the artificial error introduced for civilian users has been switched off, the accuracy is now around 20 to 50 m, and in practice an error of rather less than 10 m can be achieved. Using Differential GPS (DGPS) the accuracy can be improved still further with the aid of correction information.