\chapter{Introduction}

Prototyping, design evaluation and the measurement of physical properties in experiments make a daily occurrence in the engineering praxis. This task involves the generation and capture of electrical signals coming to and from specialized sensors, actuators and other circuitry. As the technology advanced, driven by the consumer electronics market in the pursuit of miniaturization and lower cost, a multitude of integrated sensors with digital interfaces became available. Those devices can provide a sufficient accuracy and precision for the task at hand while keeping the circuit complexity down by integrating a large portion of the necessary circuit, often including the sensor itself, on a single chip or in a compact module.

The drive for miniaturization and the advent of modern hardware buses, in particular USB (Universal Serial Bus), however, simultaneously lead to the disappearance of low level computer ports, such as the once ubiquitous parallel port, that would provide an easy way of connecting those digital devices and low level hardware in general to personal computers.

With those developments, we on the one hand have an easy access to interesting integrated devices that would make the mentioned experiments and evaluations easier, on the other, our means of interfacing them have become more complicated. When an engineer today wants to perform some measurements using a digital sensor, they are often left having to implement an embedded firmware for a microcontroller that can be connected to the PC through USB, commonly through a USB-USART adapter. This approach lets one optimize the solution for a particular task and possibly achieve higher performance, however it is time-consuming and requires knowledge of the embedded system design that is entirely removed from the desired measurement.

Clearly it would be advantageous to have a way to easily attach those integrated devices and low level hardware in general to a PC without having to burden ourselves with technicalities of the connection. The design and implementation of such a system is the object of this work.











