  This paper describes the design and development of low cost USB Data
Acquisition System (DAS) for the measurement of physical parameters. Physical
parameters such as temperature, humidity, light intensity etc., which are
generally slowly varying signals are sensed by respective sensors or integrated
sensors and converted into voltages. The DAS is designed using PIC18F4550
microcontroller, communicating with Personal Computer (PC) through USB
(Universal Serial Bus). The designed DAS has been tested with the application
program developed in Visual Basic, which allows online monitoring in graphical
as well as numerical display.
