Abstract
In recent years, artificial intelligence has had a significant impact across a broad spectrum ranging from everyday life to industrial production, education and healthcare, public administration, and defense technologies. Systems capable of interacting with text, images, audio, and unstructured data are making functions such as search, summarization, recommendation generation, decision support, and automation increasingly reliable and accessible. This transformation is not limited to the emergence of new tools; it is also fundamentally changing how institutions access, verify, and integrate information into business processes. Particularly in technical domains, generating answers grounded in verified sources has become not merely useful but essential. One approach addressing this requirement is Retrieval-Augmented Generation (RAG), which connects generative systems to institutional or domain-specific knowledge sources so that generated text is grounded in documents. Rather than relying only on the model's high-level knowledge, RAG retrieves document passages semantically related to the user's query and constructs the answer based on those passages. This creates a practical bridge between fluent text generation, traceability, and source grounding, reducing hallucination risk and improving domain-specific accuracy. This study focuses on the comparative analysis of different language models supported by RAG under the same domain documents and experimental conditions. Responses generated by different language models are examined within a single, consistent RAG pipeline built on STM32F103C8 technical documentation. The evaluation emphasizes source-grounded accuracy, technical specificity, and consistency rather than merely fluent text. By using the same document pool, contextualization approach, and standardized question set, the comparison aims to provide a fair and reproducible framework for assessing model capabilities. The methodology section presents the dataset and experimental setup in detail; the findings summarize question-level and model-level observations; and the discussion addresses practical implications and limitations. Overall, the study presents a domain-specific, application-oriented evaluation approach for the common engineering requirement to rapidly locate correct information and generate clear, source-grounded answers.