Mesa digital computadorizada

Abstract

The main goal of this work is to develop and evaluate a prototype of computer-based electronics lab for digital circuit testing with a low budget. The methodology of the process has as its first stage an analysis of commercial devices with similar functions, aiming to define a cost limit to the project, followed by a stage of study of technologies and purchase of components. The following development stages include the part of communication and definition of the protocol between device and computer, development of the firmware for circuit testing and the software for user interface and prototype assembly. The project was develop in two modules. The first module consists in a digital electronics lab using a LPCXpresso 1343 ARM-based microcontroller, in which the firmware was programmed in C language for USB communication with the computer and applying and sampling of the digital signals defined by the user in the following configurations: 8 inputs/8 outputs, 4 inputs/12 outputs, 12 inputs/4 outputs, 16 inputs and 16 outputs. The prototype features 4 KB reserved to circuit testing data storage and maximum sample rate of 1MS/s. The second module, which covers the software developed for the computer, was programmed in JAVA language, providing communication with the prototype and user interface, allowing the definition of the input digital signals to be applied and the viewing of the output digital signals made with the data sampled by the device. The technologic result consisted on the development of a digital circuit test device that, instead of mechanic switches and LEDs, uses an interface with a computer. The socioeconomic result of this project reveals itself in the composing of a prototype with cost below R$300,00, 70% less than the R$1000,00 of the average cost of digital circuit test devices in Brazil, what can ease the purchase of this equipment for education institutes or even for the students who wish to set up their own home labs.