# Investigation of an LED Strip Controller Based on a PWM Driver and a PIC Series Microcontroller
## 2 Materials and Methods  
An electronic system based on PIC microcontrollers was developed to control LED light flux (generated by LED strips). LED strip light flux parameters are controlled using PWM modulation. In order to change the light flux of the LED strip, the PWM parameters are changed with the help of a microcontroller. LED strips are powered by a PWM signal. The PWM signal is fed through 12 V MOSFET-type transistors. The PWM power signal is formed using a PWM controller/driver PCA9685 with the I2C protocol. The designed and manufactured LED controller has 16 power channels that supply LED strips with PWM-type power current. A basic diagram of the LED lighting controller is presented in Figure 1.  
\begin{table}
\begin{tabular}{l l l} \hline \hline
**LED Control Technology** & **Operating Principle** & **Advantages/Disadvantages** \\ \hline PWM & Pulse-width modulation & Universal/resolution \\ \hline DMX & Digital Multiplex & Accuracy/limited speed \\ \hline RDM & Remote Device Management & Remote control/high cost \\ \hline KNX & Konnex & Universal/complexity \\ \hline DALI & Individual control & Individual control/limited control \\  & & distance \\ \hline Microcontroller/PWM &
\begin{tabular}{l} Microcontroller/pulse-width \\ modulation \\ \end{tabular} & Universal/complex software code \\ \hline \hline \end{tabular}
\end{table}
Table 1: Control technologies for LED strips/lighting systems.  
Figure 1: General conceptual diagram of an LED lighting controller.  
The LED strip light flux control is based on changing the duration of the PWM signal. The change in PWM signal duration is performed by the PIC24 FV32 KA302 microcontroller via the PCA9685 controller/driver. It is a 16-bit microcontroller with extremely low power consumption, designed for power-constrained and battery-powered applications, with unique peripherals such as DSBOR, DSWDT, and RTCC that operate in deep-sleep mode for a leading low-power performance. The power of the microcontroller reaches about 12 mW in the working mode and about 5 \(\mu\)W in the sleep mode. The C programming language was used for programming the microcontroller. The LED controller has the ability to react to motion. LED lighting can be turned on in case of a motion. MOTION SENSORS UPSTAIRS are used for this purpose. This option allows the controller to be used, e.g., for stair lighting. Lighting is turned on only when motion on the stairs is detected. The BLUETOOTH MODULE was used to change the operating mode of the LED controller: HC-05 and control application. The LED controller is powered by a pulsed power supply 12V 25A PFC with a control, closed Mean Well. A plastic housing was designed and printed using a 3D printer to install the LED controller. The LED light flux was evaluated using a universal light (photometric) parameter measuring device KIMO 200, which has the ability to transfer data to a computer. Measurements were made at a distance of 20 cm from the LED strips. This study was conducted in phases. An electronic circuit was created to control the LED lighting strips using the details already listed. The CEM DT-3809 system was used to measure the light flux of LED strips. A unique program algorithm was developed for control, which allowed ensuring the control of LED lighting parameters using a PWM signal. The developed LED control controller was tested and studied under real conditions. The selected sequence of research stages allows evaluating the work efficiency and highlighting the operational advantages of the developed LED control system compared to analogs.