1 Reaction Rate Test Simulation and Practical Realization with LED Diodes in Tinkercad and Arduino Nano Environments Sandra Stamenković Control Systems Module Faculty of Electronic Engineering University of Niš Niš, Serbia sandrastamenkovic@elfak.rs Isidora Stevanović Control Systems Module Faculty of Electronic Engineering University of Niš Niš, Serbia isidora.stevanovic@elfak.rs Milan Pejković Control Systems Module Faculty of Electronic Engineering University of Niš Niš, Serbia milan.pejkovic@elfak.rs Luka Radičević Department for International Relations Faculty of Social Sciences University of Ljubljana Ljubljana, Slovenia lr0903@student.uni-lj.si Abstract—This paper portrays a game simulation with the aim of testing the reaction rate of people. Using the LEDs that are placed to form a circle, the reaction rate is tested by pressing a button at a specific time – when the main LED changes its color. The test was simulated in the Tinkercad environment since it is a suitable simulator for creating the foundation and adjusting the basic functions of the game. After being successfully simulated, the practical realization of the game was started using the Arduino Nano environment. Keywords—Tinkercad, Arduino, simulation, reacton rate test, tricolor LED diodes I. INTRODUCTION The aim of this project was creating a specific reaction rate test game for people of different age. The test was first simulated in the Tinkercad environment and is being practically realized using Arduino. Reaction rate will be indirectly assessed through the length of the time frame between the lighting of the main diode and the moment in which the pushbutton is pressed. The main innovation that this project is supposed to introduce is measuring the reaction rate not by timing, but rather by checking whether the user has pressed the pushbutton in the exact intended moment. This way, people’s reaction rate can be tested with the aim of gaining direct insight in their basic motoric abilities, i.e. in (psychologically) evaluating pre-school children. Besides this, another innovative aspect of this project is simulating and practically realizing the reaction rate test, which is thoroughly described in the paper. II. SIMULATION A. Tinkercad Tinkercad is a free, online collection of software tools. The author of this platform from 2011 is Autodesk, a company from San Francisco [1]. Fig. 1. An example of a 3D model in the Tinkercad environment (adapted from [2]). The platform is classified as a 3D modeling software and can be used to create models that can be realized using a 3D printer. It can also be used to create models of electrical circuits that consist of various electronic components or to write codes [1]. Since Tinkercad uses a "cloud" to store data, it enables fast and efficient processing of 3D models in real time, thus enabling anyone to do basic 3D modeling, as shown in Figure 1. On the official website of Tinkercad, there are instructions and video tutorials that can be very useful when getting acquainted with the platform, so that it can be used by both beginners and experienced designers [1]. Arduino is an open source electronic prototype platform, which allows users to create interactive electrical objects, such as electrical circuits, assemblies, etc. There are different types of Arduino, such as Arduino Uno, Arduino Nano, Arduino Mega, Arduino Due, LilyPad Arduino and others [3]. Arduino Uno was used in this simulation, since the Tinkercad platform offers only that type of Arduino. Arudino Uno offers both digital and analog pins, and in this simulation, both types were used for more efficient practical realization. In addition to the Arduino Uno, the tools offered by Tinkercad and were used in the simulation are also: two Breadboard plates, six eight-bit shift registers type 74HC595, a pushbutton, 48 LEDs, 48 500Ω resistors, and wires.