# Investigation of an LED Strip Controller Based on a PWM Driver and a PIC Series Microcontroller
## 4 Conclusions  
An LED lighting controller was developed on the basis of the PIC24 FV32 KA302 microcontroller and the PCA9685 PWM driver. Such a concept for an LED controller allows for more precise control of the lighting parameters of the LED strip. During this study, the scheme of the LED controller and the operation of an LED controller with 16 LED strip control channels were designed and investigated. PWM signal modification was used for feeding and controlling LED strips. Meanwhile, the power supply for the LED strips was achieved by modulating the voltage of the power source according to the regularity of the PWM signal variation. Analysis of the designed LED controller scheme revealed that the working regime of the LED controller was made stable and reliable using two separate components--a microcontroller and a PWM driver with an I2C bus. This LED controller design concept is simpler in design and more economical than the LED control concepts discussed in the literature review, such as RDM (Remote Device Management), etc. It was observed that the reaction time directly depended on the length of the command sent by the microcontroller. A smaller command length results in a faster response time and PWM driver response. As the results show, the response time was the lowest (0.5 ms) when the length of the command sent by the microcontroller was 1 bit. This shows that there is a linear relationship between these two variables. The use of the I2C communication protocol, which is a master-slave architecture and uses data and synchronization lines, was also found to affect the response times. Not only did the length of the command have an influence, but also the speed of the protocol used and the overall efficiency of communication. The characteristics of the PWM signal were changed programmatically in the microcontroller program code, changing the logic values from 0 to 4095. During the study, it was found that when the logic values of the microcontroller were changed from 1000 to 4000, the size of the PWM signal changed from 25 to 100%. It was observed that when the percentage of the PWM signal changed, the supply power of the LED strips changed, and this dependence was linear. The percentage of the PWM (pulse-width modulation) signal directly affected the LED strip's light flux. Decreasing the duration of the PWM signal decreased the light flux. When the percentage of the PWM signal was changed from 10 to 100%, the light flux of the LED strip changed from 100 to 1000 lm. The measurement results showed that the power of one channel changed from 1 to 12 W when the PWM signal was changed from 10 to 100%. By modulating the supply power from the power supply to the individual channels of the LED controller, it was possible to  
Figure 11: The LED light flux dependence on the power of one channel of the LED controller.  
achieve light flux regulation without the direct use of a PWM signal. This allows effectively adjusting the light flux of LED strips and adapting it to different applications. Meanwhile, the light flux changed from 100 to 1000 lm when the power of a channel was changed from 1 to 12 W. The results obtained in this study and the implemented LED controller concept open up new possibilities for controlling LED lighting systems, ensuring efficiency, reliability, and flexibility.  
Methodology, G.B. and A.I.; Software, I.S.; Formal analysis, G.G.; Writing-original draft, Z.K. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflicts of interest.