Romain Poirier - Computer science student at ENSEEIHT
Li-fi for vehicle security
In my first year of preparatory class, I collaborated with one other student on a project involving Li-fi technology.
The goal of the project was to explore the use of Li-fi technology, which involves transmitting information via light waves at high frequencies from a transmitter to a receiver.
We noticed that LED lights are widely used in cars, which inspired us to explore the possibility of using car headlights as both transmitters and receivers of information for other vehicles.
Our main goal for this project was to successfully implement Li-fi technology. We started by experimenting with using an LED as a transmitter and a photodiode as a receiver with Arduino.
The information is encoded in binary form, where a brief LED flash represents a "1" and the absence of a flash represents a "0."
We selected a 15 ms sampling period, as it is fast enough to be imperceptible to the human eye.
Our first experiment was unsuccessful due to issues with the intensity of the light. We tried repeating the test in a dark environment to rule out ambient light as the cause, but the issue persisted. Through further experimentation, we determined that ambient light was not the problem.
Despite our efforts to improve the conditions of the experiment and upgrade to higher quality materials, we were unable to successfully receive the transmitted information. As a result, we decided to switch to using an infrared transmitter and receiver. We implemented an initialization process to calibrate the transmitter and receiver, and added a delay in the coding to ensure proper transmission. With these changes, we were able to successfully transmit our signal and transmit information such as velocity to another Arduino card. We also implemented a filter to remove frequencies higher than the ones we used for transmission.
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That's why we decided to change the technology and use an infrared transmitter and receiver.
Through this project, I gained experience with conducting experiments, troubleshooting and adapting to new components and methods when necessary. I also learned how to analyze graphs, design experiments to test hypotheses, and make adjustments to improve the outcome of the experiment.