# Testing of Indoor Obstacle-Detection Prototypes Designed for Visually Impaired Persons
## 4 Conclusions
The addition of a radiator will add to the overall weight of the prototype and will create additional problems, so the advice is to power the prototype down after maximum 5 h of usage. This will be transmitted to the user by an alert message. This aspect will receive due attention in further developments of the algorithm. Tests were performed for each case over a period of 30 min, except for material tests, which were conducted for 10 min. Each result of a complete test was saved as log files and analyzed, creating a two-dimensional confusion matrix whose elements were populated with the number of correct or false results. The prototypes were miniaturized first using a breadboard, just like in the Figure 22. Materials used were a micro-controller Atmega 328, a 16 kHz quartz, two 22 nF capacitors, and a 10 kOhm resistor. After some testing, the prototypes were split into two parts: one part that has the micro-controller and the power supply and the second part hosts the ultrasonic sensor and  
Figure 22: Detector micro-controller board. the 3.5 mm jack module for the headset. In Figure 23, the\"brain\" of the detector and its components are shown, comprising the power supply and the micro-controller board. In light of the detection part, the ultrasonic element, and the headset being specifically designed to be an add on and to serve in detecting obstacles that are above the ground and not connected to it, we provide a suggestion for the position on the body for the device to be worn; see Figures 24 and 25:  
The two parts are connected by a cable that allows the transmission of data from the ultrasonic sensor to the board and the transmission of audio messages to the jack module, as seen in Figure 26.  
Figure 24: Placed on the head. Figure 23: Detector micro-controller board. Figure 25: Placed on the torso. Author Contributions:Conceptualization, R.P. and R.G.V. ; Hardware prototype development, R.P. and L.G. ; Software development, R.P. and R.G.V. ; Testing methodology, R.P., R.G.V. and I.-A.P. ; Testing results analysis, R.P., R.G.V., I.-A.P. and L.G. ; Supervision, R.P. ; Validation, R.P., R.G.V., I.-A.P. and L.G. ; Writing--original draft, R.P. ; Writing--review and editing, R.G.V., I.-A.P. and L.G. All authors have read and agreed to the published version of the manuscript. Funding:This paper was financially supported by \"Network of excellence in applied research and innovation for doctoral and postdoctoral programs/InoHubDoc\", a project co-funded by the European Social Fund financing agreement no. POCU/993/6/13/153437. Institutional Review Board Statement:Not applicable. Informed Consent Statement:Data are available upon request from the corresponding authors. The data are not publicly available due to privacy. Acknowledgments:The input and test results of this prototype were made possible thanks to the students of the Special School for the Visually Impaired from Cluj-Napoca and the Ilas Crina. Conflicts of Interest:The authors declare no conflicts of interest. Appendix A Prototype Test Results for Square Obstacle Placement So It Covers Half of the Prototype's Detection Cone