In this article, we present an approach to the ABZ 2020 case study, that differs from the ones usually presented at ABZ: Rather than using a (correct-by-construction) pproach following a formal method, we use MISRA C for a low-level implementation instead. We strictly adhere to test-driven development for validation, and only afterwards apply model checking using CBMC for verification. In consequence, our realization of the ABZ case study can serve as a baseline reference for comparison, allowing to assess the benefit provided by the various formal modeling languages, methods and tools.