4 IEEE TRANSACTIONS ON EDUCATION, VOL. 47, NO. 1, FEBRUARY 2004 Stand-Alone Laboratory Sessions in Sensors and Signal Processing Bruno Andò, Member, IEEE, Salvatore Graziani, Member, IEEE, and Nicola Pitrone Abstract—Real laboratory experiments can help students to gain a better understanding of theoretical problems. Great efforts are needed, however, to improve the quality of laboratory sessions, and a large number of tutors are usually required. Moreover, students may lose time because of hardware failure or an inefficient experimental setup. Several educational tools (based on virtual instruments) have been developed allowing for optimized time scheduling and remote access to laboratory sessions. Drawbacks related to hardware failure have not, however, been seriously addressed. This paper proposes an educational tool made up of a user-friendly interface controlling experimental boards. It basi- cally consists of an array of optical sensing devices connected to suitable conditioning circuits, which are interfaced to a virtual instrument by means of a data acquisition system. To solve the previously mentioned drawbacks, a solution based on both pre-cabled hardware and PC-based measurement stations has been adopted. Moreover, the ability to configure self-educational tasks optimizes time scheduling for students during laboratory activities. The proposed system allows students to improve their knowledge in the field of optical sensing devices, virtual instrumentation, data acquisition systems, and signal processing. The paper describes an application of the tool as a simple system for surface recognition. This application is one of the laboratory tasks performed in measurement classes during this engineering course at the University of Catania, Catania, Italy. Index Terms—Measurement classes, optical sensors, signal con- ditioning, signal processing, virtual instrument. I. INTRODUCTION C LASSES in electronic measurement are closely involved with laboratory experiences, aimed at guaranteeing a deeper understanding of the real problems related to measure- ment sessions. Both the evolution of measuring instruments and the ever-growing number of students attending each class require a new approach to laboratories. Computers are widely used during the teaching process [1]–[5]. The use of computers in measurement laboratories al- lows the learning process to be speeded up, and this use allows students to approach new measuring technologies early in their career [2]. Low-cost PCs used in laboratories are equipped with software packages, e.g., LabVIEW by National Instruments, and also with hardware devices, such as data acquisition (DAQ) boards and networking cards, to build modern distributed Manuscript received March 19, 2002; revised January 13, 2003. The authors are with the Dipartimento Elettrico, Elettronico e Sistemistico (DEES), Engineering Faculty, University of Catania, 6–95125 Catania, Italy (e-mail: bando@dees.unict.it). Digital Object Identifier 10.1109/TE.2003.818276 measurement systems (possibly with stand-alone measurement instruments) [6]. Another interesting consideration concerns the need to include nontraditional subjects in measurement application fields. Courses in electric and electronic measurement must be adapted to consider new measurement topics. As an example, signal processing and image processing are two topics with a large number of real applications [6]–[8] (introduced in several courses), which require the nontraditional approach to mea- surement sessions [9], [10]. In this context, virtual instruments play an important role because of their extreme flexibility and easy-to-use features. In the past, several systems based on virtual instruments were developed to perform suitable educational tasks [11]–[13]. Drawbacks related to hardware failure (e.g., wire connection, unsuitable bonding, and so on) were not, however, addressed, and they can cause loss of time for students performing the experiments. This paper describes a new teaching tool to be used by under- graduate students during laboratory sessions. The system goal is to familiarize students with subjects, such as virtual instru- ment design, general-purpose signal conditioning circuits, and basic signal processing. It uses virtual instruments, managing already cabled and configured hardware, thus avoiding draw- backs related to hardware failure. Moreover, the ability to adopt stand-alone and self-explaining tools reduces the effort required for the teaching staff and allows students to optimize their time- scheduling during laboratory sessions. The proposed tool aims to improve student knowledge about infrared (IR) optical sensing devices, about the fundamentals of signal processing and data acquisition systems, and about an array of optical sensors and suitable conditioning circuits. The hardware of the system communicates with a PC via a general- purpose DAQ card, and a virtual instrument is adopted to control the hardware and manipulate the data acquired [6]. The main features are flexibility in terms of both the ap- plication, which can be defined case by case, and the hard- ware/software solutions adopted, which allow for suitable signal processing. The user (i.e., the student) is forced to interact with the measurement device and to familiarize himself or herself with instrumentation, data acquisition procedures, and the funda- mentals of signal processing [1]–[3]. The experiment described is used with students attending a six-month course in Elec- tronic Measurements, scheduled in the fourth year of a five-year course in Electronic Engineering at the University of Catania, Catania, Italy. It can, however, be a useful training tool for any 0018-9359/04$20.00 © 2004 IEEE