Design and construction of a currency coin counting and sorting machine.

Abstract

The various works done to test different coin currencies to construct their own currency coin counting and sorting machines do not have Ugandan Shilling coin currency included and thus the one for Ugandan currency coins has not been developed, yet methods such as edge detection and use of microcontrollers are applicable for Ugandan coins although the parameters used to differentiate and sort the coins will differ since the currencies are not the same. The unavailability of a Ugandan currency coin counting and sorting machine means that manual coin counting and sorting is the only option. The manual alternative method encounters a lot of human errors thus making it less efficient. The manual classification of coins of various denominations and finding the sum of the coins is a slow tedious process and is at times required to be done quickly especially in fast paced environments that handle a lot of coins such as banks and supermarkets in Uganda. Therefore there is a need to find a solution to manual coin counting and sorting. In order to solve this problem of manual counting and sorting, a currency coin counting and sorting machine test prototype was developed to count and sort Ugandan currency coins through the use of CATIA software, Arduino hardware, Arduino software and mechanical based sorting system. The components of the machine were designed and assembled in CATIA software before going into the actual construction. The major Arduino hardware components used in the machine were servomotor used to turn the rotating disc in the hopper that takes the unsorted coins into the system, infrared transceiver that detects coins that go into the system for sorting, Liquid Crystal Display that displays the total number of coins detected by the infrared transceiver and Arduino Uno and Mega boards that store instructions for the servomotor and coin counting system respectively. The servomotor was powered by a computer whereas the coin counting and display units were powered by a battery. Arduino Integrated Development Environment software was used to code and programming was done in C++ language to develop the coin counting algorithm. The mechanical based sorting system comprised of a coin sorter which would distinguish the coins as they slide down on it based on diameter for the UgShs.50, 200 and 500 and thickness for the UgShs.100 and 1000. The currency coin counting and sorting machine prototype was tested multiple times and the general performance of the prototype was found to be fair. The machine prototype was functional to some extent as errors would occur occasionally with coins getting jammed or stuck in the system. The efficiency of the machine prototype was calculated to be about 90%. The repeatability of the prototype was also calculated and found to be about 80%.