Design of an ARM - based Automatic Rice - Selling Machine for Cafeterias

To address the problems of low selling efficiency, poor sanitation conditions, labor-intensive requirement, and quick rice cooling speed in manual rice selling in cafeterias, especially in colleges and secondary schools, this paper presented an Advanced RISC Machines (ARM) microprocessor-based rice-selling machine for cafeterias.The machines consisted of a funnel-shaped rice bin, a thermal insulation box, and a conveying and scattering mechanism.Moreover, this machine exerts fuzzy control over stepper motor rpm, and the motor drives the conveyor belt with a scraper to scatter rice, deliver it, and keep it warm.Apart from an external 4*4 keyboard, a point of sale (POS) machine, an ARM process and a pressure sensor, the machine is also equipped with card swiping and weighting mechanisms to achieve functions of card swiping payment and precise measurement, respectively.In addition, detection of the right amount of rice and the alarm function are achieved using an ultrasonic sensor and a beeper, respectively.The presence of the rice container on the rice outlet is detected by an optoelectronic switch.Results show that this rice-selling machine achieves precise measurement, quick card swiping, fast rice selling, stable operation, and good rice heat preservation.Therefore, the mechanical design enables the machine to achieve its goals.