Specific realization function
The system consists of STC89C51 single-chip microcomputer + LCD1602 liquid crystal display + L298N control module + DC motor + DS18B20 temperature sensor.
Specific functions:
(1) Realize the control of the motor by L298N, use LCD1602 to directly and clearly display the temperature;
(2) Realize the control of the motor speed based on the measured temperature (using the motor to simulate the air conditioner frequency conversion system);
(3) In automatic mode, the higher the temperature, the higher the duty cycle and the faster the number of revolutions. In manual mode, the motor speed can be controlled by pressing the button.
design background
In recent years, with the rapid development of the air-conditioning industry, it has greatly occupied the market. Compared with a fan, an air conditioner has a powerful cooling function, which can quickly and effectively reduce the ambient temperature. However, there are also many problems with air conditioning. For example, if you blow for a long time in summer, you can easily get air-conditioning disease. If the indoor and outdoor temperature is not balanced, you can easily catch a cold. At the same time, due to forced cooling, the elderly and children can't stand it easily. When the air is not circulated, it is easy to breed bacteria, and the air conditioner consumes more energy. Therefore, reasonable control and use of air conditioners is very important. With the development of science and technology and the improvement of people’s living standards, household appliances products tend to be automated, intelligent, low power consumption, environmentally friendly and humanized, and intelligent temperature control controlled by a microcomputer Air-conditioning appeared.
In order to solve the above-mentioned problems, the use of single-chip microcomputers has the characteristics of miniaturization and multi-function, which can achieve a variety of design requirements, and is applied in many fields. This paper designs an air-conditioning temperature control system based on single-chip microcomputers. This system uses a high-precision integrated temperature sensor, controlled by a single-chip microcomputer, can display real-time temperature, and adjust the frequency conversion system of the air conditioner according to the temperature to realize air conditioning control, improve the intelligence and humanization of the air conditioner, and save electricity.
hardware design
The figure shows the hardware design of this system. Specifically, the hardware circuit is composed of the following modules:
(1) The smallest single-chip microcomputer system. It is used to drive and control other modules to realize the overall function. It uses AT89C51 single-chip microcomputer as the core chip, supplemented by reset circuit and crystal oscillator circuit;
(2) Button module. It is composed of three buttons to realize the switch of automatic/manual state and the control of motor speed (acceleration and deceleration);
(3) Display module. Display the real-time temperature value measured by DS18B20 through LCD1602 liquid crystal display;
(4) Motor and its drive module. Simulate the work of the air conditioner inverter through the rotation of the motor.
software design
According to the design requirements of this article, on the basis of hardware circuit design, specific functions that need to be realized through software programming:
(1) Drive each module to work and realize the clear display of LCD1602;
(2) Button setting function. The interactive single-pole double-throw switch is used to switch between automatic and manual states, and the other two key switches are used to control the motor speed (acceleration and deceleration);
(3) Realization of temperature detection function. Realize real-time detection and display of ambient temperature;
(4) The drive and control of the motor. Realize motor speed control based on temperature.
The specific design process is shown in the figure.
Schematic diagram
The system schematic design adopts Altium Designer19, as shown in the figure.
program
This design uses KEIL5 software to realize the program design, as shown in the figure.
Simulation implementation
This design uses protues8.7 software to realize the simulation design, as shown in the figure.
All information
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