| Temperature, humidity and illumination are three important conditions for the growth of plants. The accurate measurement for the temperature and humidity can help the fruit trees to grow better and then bear more fruits. Therefore, the measurement for temperature and humidity is very important and meaningful. Focus on the characteristics of the temperature and humidity for the orchard, in this paper, we propose an autocontrol system digital for temperature and humidity based on the technology of wireless transmission. The new control system has the specialty of advanced technology and low cost, and can control the irrigation of the orchard remotely, regularly, and quantitatively, and then solve most of the difficulties existing in the current irrigation system in some sense.In this paper, we has designed and produced an autocontrol system for temperature and humidity based on a kind of wireless transmission technology. First, we figure out the whole picture for the system; then, we design the hardware for each part of the system; after that, we use the AT89C52 single chip microcomputer as the main part of the system to integrate each part; in the end, to make the system work successfully, we study the circuit diagram and then design the flow chart for each running device part and the whole system. The system is made up by the two parts: one is the indoor control terminal, the other is the outdoor working terminal. These two parts are connected by the wireless transmission system, which can also exchange information between these two parts. The indoor control terminal include the display module, the keyboard input module, and the main control module; the outdoor working terminal include DS18B20 temperature sensor, the DHT11 humidity sensor, electromagnetic valve, solar panels, multiple power supply charging module and so on. In our design, we use two pieces of n RF24L01 wireless transmission devices, which can not only serve as the sender to send data but also can be used as the receiver to receive the data, and thus reduce the problems resulted in the designing for the complex line of communication effectively. We also use a sensor module in our temperature acquisition system, and use LCD1602 as our LCD display module.In order to save energy, we use the battery as the main power for the system circuit inside, and use solar panel as the main power for the outdoor work system. In real operation, we only need to set the clock on the in door control terminal, at the same time, the LCD will display the values for temperature and humidity for the orchard. After that, the LCD will display the countdown, and then the clock data will be transferred to the work system outdoor by the wireless transmission. The outdoor working terminal then turn on the solenoid valve according to the command send out by the indoor control terminal, and reckon by time automatically, which make the time for irrigating being controlled exactly, and then achieve the goal of saving water. All the codes related the work of this paper are written by C language.After designing and debugging repeatedly, we have created up a physical prototype system, and the system satisfies most of our requirements. That is, the system can measure the temperature successfully, and transfer it to the display by wireless transmission system and then display it. In current, the temperature the system can measure range from-55℃ to 125℃, and the error is about 1℃;Humidity measure range is 20%-90%RH, 0-50℃, accuracy of 5%RH, a resolution of 1. |
