Research On Debugging Interaction Of IoT Devices Based On Visible Light Communication

In order to meet the needs of information interaction of edge sensing systems in IoT applications,a near-field communication method with convenient transmission and low power consumption can be adopted.However,the traditional near-field communication method is based on electromagnetic wave broadcast communication,and the use of broadcast communication to implement online debugging for nodes has inherent security shortcomings.On the other hand,if a node deployed in an unmanned area has a wireless communication failure,it will cause the node to lose contact with the network.At this time,the traditional means of debugging and repairing interactions that rely on wireless networks may fail.Because the hardware structure of the sensor network node is simple,it is generally difficult to provide additional debugging methods.In this paper,by tapping the potential of various optical modules on existing sensor nodes and mobile terminals,and without modifying the hardware,this paper proposes a debugging interaction method based on visible light communication for faulty sensor nodes that have lost communication.The method realizes a hybrid duplex debugging interactive system based on visible light.In this system,the data transmitted in the downlink is mainly used for repairing updated code numbers,and the data volume is large.However,the sensor node light sensor has a large light-sensitive delay,which causes the data unit transmission time to be too long,and the overall code data transmission rate is low.To this end,this paper proposes a double-headed pulse interval modulation CDH-PIM based on compressed expression.The core idea is to use the special symbols to compress the repeated data appearing in the code data,which can effectively improve the data transmission rate.Experiments show that CDH-PIM has a 98.6% improvement in data transfer rate compared to PWM,and a 79.8% reduction in energy consumption,a 14.8% increase in throughput and an 8.7% reduction in energy consumption compared to DH-PIM.The system uplink is mainly responsible for transmitting the debugging information sent by the sensor node.Its information receiver is an optical camera on a mobile device.For this reason,we use the working mechanism of the rolling shutter of the camera to design an efficient data transmission method.However,due to the high directivity of visible light,slight shaking may also affect data transmission.In addition,because the optical camera completes the shooting in image frame units,and the time it takes for the node LED to send a frame of data needs to match the image frame of the optical camera the exposure time must be consistent to successfully transmit the debugging information.To this end,we further propose a feedback frame synchronization scheme for rolling shutters.In this synchronization scheme,the mobile device communicates with the nodes and cooperates to complete the synchronous transmission and reception of signals.The captured images are detected in real time.When data is lost,the mobile device sends feedback information,retransmits the lost data and synchronizes again to ensure data transmission quality.The frame synchronization scheme can reach a data transmission rate of 600b/s at 30 fps.