Technological systems are vulnerable to faults. In many fault situations, the system operation has to be stopped to avoid damage to machinery and humans. As a consequence, the detection and the handling of faults play an increasing role in modern technology, where many highly automated components interact in a complex way such that a fault in a single component may cause the malfunction of the whole system. This work introduces the main ideas of fault diagnosis and fault-tolerant control under the optics of various research work done in this area. It presents the Arduino technology in both hardware and software sides. The purpose of this paper is to propose a diagnostic algorithm based on this technology. A case study is proposed for this setting. Moreover, we explained and discussed the result of our algorithm.