Abstract:

The purpose of the authors of this paper is to share their experience in the use of the Multisim and Proteus software environments as well as the open source Arduino platform for teaching and examining mixed circuits in engineering higher education.

Multisim and Proteus are Spice (Simulation Program with Integrated Circuit Emphasis) based and are intended for simulation and analysis of analog, digital and mixed-signal circuits. Their interface is constantly improved and their capabilities are expanding. This makes them suitable for teaching and mastering mixed-signal circuits through circuit modelling.

An Arduino 2560 integrated environment was chosen to serve as the microcontroller, as it is is intended for application development in various fields. In the current article it is used to extend the capabilities of the Texas Instruments Analog System Lab Kit PRO (ASLK PRO) and to enhance the ability of the students to develop their own projects.

Proteus is suitable for simulating, testing and analyzing the processes taking place in digital-to-analog converters (DACs), since it keeps the teaching focused on the concepts of the course and provides the opportunity to study the hardware and software aspects of the material taught. Trainees learn about the engineering workflow: designing and simulating the feasibility of circuits using virtual tools.

A simulation model of a DAC with summation of voltages, made of 8 bit R2R matrix was created in the Proteus Design Suite. It allows the trainees knowledge of the principle of the superposition theorem to be easily reinforced. In order to demonstrate the resolution of the DAC, the input binary combinations are generated by an Arduino Mega 2560.

The output waveforms observed with the EasyScope software oscilloscope are displayed on a computer monitor. EasyScope allows control and adjustment of the generated signals so that their parameters can be read with high accuracy.

A DAC simulation model with current summation was created in the Multisim environment. A Multisim simulation is a good method for the successful training of the students to prototype a real circuit. The model uses switches to send different combinations of the bits of the digital input signal, for which currents and voltages in the circuit branches are measured with measuring probes without the need to wait or to restart the simulation. The article presents the theoretical calculations for the resolution of a 4-bit DAC and an 8-bit DAC and compares the obtained simulation results.

The simulation models can be deployed using real hardware (a laboratory platform) to conduct physical experiments. Proteus and Multisim enhance the students' creative thinking and prepare them for the physical examination of these types of DAC.

The trainees verify the results of the DAC simulation tests using the laboratory models created. The results of the experimental studies are presented.

Training future engineers necessitates using diverse strategies and resources for teaching, training and support. The transformation of the learning process into a modern educational environment requires students to master methods of knowledge, among which the combination of simulation and experimental study of mixed-signal circuits is becoming increasingly important.

Keywords:

Proteus, Multisim, mixed-signal circuits, engineering higher education.