Automatic coffee grinding and brewing process with NUC140 microcontroller

Abstract

One of the parameters that determine the quality of the coffee beverage is by grinding the coffee beans correctly. In addition to proper grinding process, water temperature settings also become an important part. Grinding and brewing process must be done in a short time so that the taste of the coffee bean is not lost and the quality is maintained. A control system based on PID (Proportional Integral Derivative) is used to maintain proper water temperature. The components used is LM35 temperature sensor, Solenoid Valve, AC dimmer, and DC Motor that is connected to a Nuvoton NUC140 module that serves as the main controller of the system. Temperature control is done by adjusting the voltage of the AC dimmer circuit to heat the element with the PWM changes removed from the microcontroller. The PID parameter is determined using the Ziegler-Nichols method. The test results with Kp = 13, Ki = 116, and Kd = 29 systems have a response with a constant time of 613 seconds and the air temperature can be stable at 90 ° C with a steady state error of 1.1%. Overall, the system can process 8 grams of coffee beans for 5 minutes started from grinding the coffee beans to brewing.