Teaching electronics involves a robust practical component where students acquire knowledge, skills, and competencies related to circuit assembly, complementing theoretical concepts. This practical aspect requires several physical elements, including electronic components, prototyping boards, power supplies, and oscilloscopes. Such requirements can limit autonomous activities, especially in online teaching or situations where in-person instruction is not feasible. To address these challenges, it is crucial to utilize simulation programs that accurately replicate the laboratory environment.

Autodesk Tinkercad enables the design and simulation of electronic circuits through a web interface that displays both circuit diagrams and the physical assembly of components with power and measurement equipment, mimicking laboratory setups. This helps students connect schematics, simulation and physical assembly, reinforcing their understanding from face-to-face sessions with practical instrument experience. However, Tinkercad has limited import and export capabilities, and exercise evaluation is restricted to visual inspection, precluding automatic evaluation and assessment even for simple, univocal assemblies.

To facilitate evaluation, we developed a Python-based tool for analyzing, comparing, and validating electronic circuits created in Tinkercad. The tool uses BRD files as input, a format based on XML, which is the only text-based export option available in Tinkercad. The process begins by analyzing the files to extract relevant information about elements and connections. Using graph theory, the tool relates two circuits, framing the comparison as a quadratic assignment problem to maximize the objective function. The graphs of each circuit are represented by matrices based on component connections, including additional virtual connections with their specific typology. These virtual connections are restricted to ensure the optimization process does not alter the intrinsic characteristics of the components. The comparison quantifies differences between assembly schemes based on the objective function's value.

The evaluation tool has been validated with various circuit assembly examples, accurately detecting discrepancies compared to the reference assembly. This system significantly aids in correcting practical exercise submissions, easing the teacher's workload. It also has the potential for future integration into learning management systems such as Moodle.

Keywords: Automatic evaluation, electronics, project-based learning, circuit simulation, graph theory, learning management systems.