Abstract
SCM, known as micro-controller, was first to be used in the industrial control area and developed from a dedicated processor with only a CUP inside the chip. At the beginning, it was designed to make the computer system smaller and easier to match those complex control devices, which has more strict volume standards, by integrating enormous peripherals and CPUs into a single chip. INTEL's Z80 was the first processor designed in accordance with this idea, after when SCM and dedicated processors parted their ways of development. SCM is run by software program and can be modified. Through different software program, it could provide different functions, which is hard for other devices. SCM, as the smallest computer system, can do simple calculation and control operation using only one IC (Integrated Circuit). Small as it is, SCM plays a decisive role in the whole device, and now it has been used in all aspects of our life.
This research uses ATmega16-SCM to present a temperature acquisition and display system. It is C language programmed and can achieve the following functions: real-time temperature displays, set limits of temperature alarm and so on. This design consists of four components as below: temperature acquisition circuits, LCD display circuits, alarm circuits and button-control adjustment circuits. The AVR-SCM uses the temperature sensor DS18B20 to achieve the temperature acquisition function; uses four buttons to set the parameters and adjust itself; shows the real-time temperature on the LCD1602 screen; when the temperature meets the upper or lower limits, the buzzer and alert will ring. The temperature sensor for this design has a degree of accuracy of 0.0625℃, so it’ll apply to many circumstances.
This research describes the basic principles of ATmega16-SCM and analyzes the function of every pin in detail. At the meantime, it gives a clear look on how LCD1602 screen and the temperature sensor DS18B20 work and the process of design.
Finally, the researcher tested and debugged this simulated system with PROTEUS, so as to ensure its feasibility.