Today we designed the block diagram for our system and develop some theories to better understand the project.

Basic System

The upper heating elements and the lower heating elements of the oven will be connected to our AC circuit by passing through a relay, which we’ll use as a switch to control the oven. The thermocouple will act as a temperature measurement to send the temperature data (which is an analog signal) of the oven to the A/D convertor component of micro-controller. Therefore, the temperature will correlate with the circuit voltage by some constant, and we can denote as V = kT. The oven’s fan will also connect to a relay in a separated AC circuit. The oven’s door state should also be provided to the micro-controller. For instance, if the door is opened, then we want the process to stop.

For user interface, it can either be a LCD display or a PC, or both. The data after being computed by the micro-controller will be sent to these components to display the information to the user. The LCD display should provide at least the current processing time, temperature and stage of the oven. There can also be a separated keypad for inputs where the user can manually set up and control the desired temperature, time, fan speed, stage or other elements for the ovens.