What visible light is in our mobile phones, and which ones are bothering our lives? How to solve it?

At present, passive radio frequency identification technology widely used uses radio frequency signals to power electronic tags and read the data information contained in them. This form of communication is more convenient, but it requires additional reader equipment. In contrast, the communication mode using visible light is not only simple but also does not need additional equipment. This characteristic makes visible optical communication technology get more and more attention. Moreover, the use of light-emitting devices similar to LED lamps is very popular, which makes these light-emitting devices may become the sending end of visible light signals, so that the deployment of visible light communication systems will become very easy.

in addition, with the development of technology, the functions of smart phones are becoming more and more perfect, and their computing power has also been better improved. Therefore, the mobile phone has enough computing power to complete the workload in the visible light communication system. Therefore, it is possible to use the mobile phone as the receiving end of the visible light communication system to receive, read and identify the visible light signal.

technical realization factors:

the purpose of the present invention is to provide a visible light communication method, which is based on an LED dot matrix and a mobile phone camera and can transmit data by using visible light. The proposed communication protocol can effectively control the data transmission process and ensure the security and stability of the data in the transmission process.

in order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

in the visible light communication system, the transmitting end encodes the data to be transmitted into a binary data stream, and the binary data stream is represented by an LED lattice. The encoding process is as follows:

Step 1, express the data to be transmitted as ASCII binary code.

step 2: Base64 encode ASCII binary code to obtain Base64 string.

step 3, express Base64 string as ASCII binary code.

Because ASCII encoding uses 8-bit binary bits to represent a character, while Base64 encoding uses 6-bit binary bits to represent a character, such an encoding scheme encrypts the data to be transmitted and improves the security of data transmission.

the encoded binary data is expressed by the on-off state of each LED lamp in the LED lattice in units of frames, that is, a data frame is represented by the state of an 8*8 LED lamp. After the receiver successfully reads the information represented by the LED lattice, it decodes each data frame to obtain the original data to be transmitted. The decoding process is as follows:

Step 1, the obtained data frame is decoded in ASCII to obtain the Base64 string.

step 2: Base64 decode the Base64 string to obtain ASCII binary data.

step 3, restore the ASCII binary data to the original string.