1. The principle of intelligent control of LED lights
This system uses STC89C51RC single-chip microcomputer to make a Bluetooth switch LED light system, which is connected to an Android smart phone through a Bluetooth communication module, and then uses the developed App to control the switch of the three LED lights, so as to realize the intelligent switch control of the lights without needing to Manual operation of turning on and off the lights at the fixed switch. The smart phone can control three LED lights at the same time, and the switches of the three lights do not affect each other and are independent of each other. The communication diagram is shown in Figure 1.
2. The scheme design of the intelligent control system
2.1 Hardware design of intelligent control system
The hardware design is divided into three parts: MCU selection design, Bluetooth module selection design, and other components selection design. The specific description is as follows:
(1) STC89C51RC single-chip microcomputer is used for the selection of single-chip microcomputer. STC89C51RC is an in-system programmable chip (In System Programming, ISP) using 8051 core, with a maximum operating clock frequency of 80 MHz. The power supply system adopts the integrated voltage stabilizing module LM7805, which has the characteristics of low cost and high conversion rate. It is suitable for the production of small projects. The voltage stabilization range is 6 to 12 V. This design can be matched with six dry batteries and 2 s/ The 3 s lithium battery module provides power supply, which is highly portable. If you need an external 5 V high-power electrical appliance, you can use the LM2596S module.
(2) The choice of Bluetooth module is the HC-06 Bluetooth module, which has a working voltage of 3.3 V, a wireless receiving and transmitting frequency of 2.4 GHz, a volume of 27 mm × 13 mm × 2 mm, and a built-in 8 M Flash module with powerful functions. Customizable software, suitable for various Bluetooth devices, Bluetooth module technology can refer to literature.
(3) The remaining components are selected. The components of the control system include 10μF electrolytic capacitor, 10 kΩ color ring resistance, 1 kΩ color ring resistance, DIP40 MCU socket, 22 pF ceramic capacitor, 11.059 2 MHz crystal oscillator, 7 cm×9 cm ten thousand hole plate , 2.5 mm pin header, self-reset button, DC 5 V power socket, DC 5 V USB power cord, LED power indicator, 3 LED light-emitting diodes, welding jumper, 4.7 kΩ resistor, DuPont wire, wire, 1 kΩ color ring resistance, solder wire.
The hardware circuit of the control system contains a crystal oscillator module and a reset module. The reset module is composed of a 4-pin button plus a 1μF electrolytic capacitor and a 10 kΩ pull-up resistor. When the switch is pressed, the module will give the reset pin of the single-chip microcomputer a high level for a longer period of time to make the internal program of the single-chip microcomputer Restart to prevent the program from running away and ensure the safety and stability of the system. The crystal oscillator module is composed of a 11.059 2 MHz crystal oscillator and two oscillating capacitors. The value range of the capacitor is generally 22 pF to 30 pF. The purpose is to give the system a continuous and stable clock frequency. This module needs to be connected to the specific pins of the microcontroller, such as the reset module needs to be connected to the RST pin of the microcontroller, otherwise it is useless. In addition, the crystal oscillator circuit needs to be connected to a specific crystal oscillator pin.
2.2 Software design and realization of intelligent control system
The system is composed of a microcontroller control part and an Android system App. Users can wirelessly control the LED lights through the Android system App, and the microcontroller control part executes the instruction. The control system flow is shown in Figure 3.
The user opens the Android phone program interface. Turn on the bluetooth of the mobile phone, connect to the bluetooth module of the microcontroller, and control the switch of the LED light through the mobile phone interface to complete the test of the control system. The intelligent control of the system is realized through C language programming, the program is compiled and debugged in the Keil C51 environment, and the program is burned into the single-chip microcomputer through the burning software.
to sum up
The Android-based intelligent LED switch remote control system has the characteristics of good stability, low cost and simple operation, which brings users a more convenient and comfortable life experience, greatly enriches people's lives and improves people's quality of life. At present, the system is in a stage where it can control LED lights within a certain range, but the remote control of the switch of LED lights has not yet been implemented, and further research is needed.