The Design of Light Intensity Measurement System Based on Programmable Controller

With the rapid development of social science and technology, science and technology play an increasingly important role in people's daily life. People's demand for products that are conducive to their convenience is increasing. The traditional light intensity measurement has a single function, low accuracy, and can not adapt well to the development and progress of society. Today, it is not enough to meet people's diverse needs for light measurement. The illumination intensity measurement system controlled by programmable controller can collect data. It has the advantages of flexible programming, accurate measurement, timely message communication and convenient detection. The system design can automatically detect the size of the light intensity under the measured environment and display it in a long-range to let people know the intensity of the light. When the light intensity is greater or less than the range of illumination it should be, alarm and switch curtains and lights. The system design uses BH1750FVI sensor to measure the light intensity, STC89C52RC chip to process data and control the system, ESP8266 module to transmit data wirelessly and display it on the mobile phone, and step motor and relay to switch curtains and lights. The whole system uses MQTT's Internet of Things communication protocol, which makes it very convenient to expand the system on the original basis. The introduction of ESP8266 module also makes full preparations for the adaption of smart home devices such as millet house and HomeKIT, bringing unlimited possibilities to the system.