## 5 Conclusions  
In this article, a low-cost easy-to-install Master-Slave intelligent LED light-controlling system has been proposed, which is based on Internet of Things (IoT) techniques. The proposed system has been adopted and installed so the LED lights' brightness in the same zone can be changed simultaneously to save energy consumption. Moreover, the parameters of the LED lights can be directly set. Furthermore, the related collected data can be uploaded to the cloud platform. In this article, we have used a parking lot as a case study. Experimental results showed that when the proposed system is installed in a zone with few people, the energy-saving rate will be as high as 90%. Moreover, when 12 people pass by the zone within one hour, its energy-saving rate can reach up to 81%. Therefore, for large-scale fields, the proposed system can also directly set the parameters of LED lights via Wi-Fi 2.4 G Hz wireless transmission modules to uniformly set each LED light in the large-scale field parameter setting. Therefore, the proposed system is not only suitable for small families (as long as the lamp is replaced with the proposed IoT-based intelligent LED light), but it is suitable for large-scale public zones such as buildings, communities, factories, warehouses, etc., where people and vehicles pass by for a short time, and even general street lighting is also a very suitable target that could adopt the proposed system. As a result, the detailed calculations have been demonstrated in the case study for ESR calculation section. In a parking lot with 16 areas (each area has 16 LED lights), if 12 people pass by each hour and each degree is priced at CNY 4 (yuan), it will be available every year. It saves CNY 108,988.416 and reduces the CO\({}_{2}\) emissions of 16,974.848 kg. What's more amazing is that its energy-saving rate is as high as 81%. The most suitable area for the work is where people and vehicles will pass by for a short time. If it is used in an office, it is not practical. In the future, we will strengthen and improve this work to be used in office environments (places where people stay for a long time). The current preliminary idea is to combine the help of counters to distinguish whether there are people in the space correctly. Finally, the advantages and contributions of this work compared to other systems are summarized, as follows. * We have improved the traditional sensor lights with motion sensors of low- and highlight modes. LED lights in the same zone will simultaneously change to the high-light mode instead of sequentially lighting up each LED. * The proposed system can retain the original lamp holder without wiring and setting up a server. It can achieve the energy-saving purpose of an intelligent LED light-controlling system. * The parameters of the LED lights can be set directly via the IoT, and the collected data can also be uploaded to the cloud. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Electricity Consumption** & **Electricity Consumption** & **Power Saving** & & **Electricity Bills** & **Reduced CO\({}_{2}\)** \\
**before Improvement** & **after Improvement** & **(Degrees/Year)** & **(Degrees/Year)** & **ESR** & **Savings** & **Emissions** \\  & & & & **(Yuan/Year)** & **(kgCO\({}_{2}\)e)** \\ \hline
33,638.4 & 6391.296 & 27,247.104 & 81\% & 108,988.416 & 16,974.848 \\ \hline \end{tabular}
\end{table} 
Table 8: Reduced electricity consumption, cost, and carbon emissions of a parking lot during the same year. * The proposed system has a high power-saving rate. If the proposed system is installed where few people pass by, the energy-saving rate will be as high as 90%. When 12 people pass by every hour, the energy-saving rate is 81%. Conceptualization, C.-T.L. and H.-M.C. ; methodology, C.-T.L. and L.-B.C. ; software, C.-T.L. and L.-B.C. ; validation, C.-T.L., C.-J.H., and W.-C.L. ; formal analysis, C.-T.L. and C.-J.H. ; investigation, C.-T.L. and L.-B.C. ; resources, C.-T.L. and W.-C.L. ; data curation, C.-T.L. ; writing--original draft preparation, C.-T.L. and L.-B.C.