This system is a remote automatic control system for smart home environments based on infrared and GSM networks. The working principle is as follows: the user sends a command short message through his mobile phone, and the GSM module at home receives the command and sends it to the host (single-chip microcomputer). The host transmits the command to the corresponding extension (microcontroller) through infrared processing. After the extension processes the command, the corresponding device is started, the command given by the user is completed, and the response is replied to the host. After receiving the response, the host sends a reply short message through the GSM module to report the user completing the command. If the host does not receive the reply message of the extension within the specified time (here, timing 60s), the operation is considered invalid, and the reply operation invalid message is sent to the user's mobile phone, requesting the user to reissue the command. If the short message received is incorrect, the host will immediately reply to the user that the operation is invalid and request to reissue the command. The system structure is shown in Figure 1.
Figure 1 system composition diagram
MCU and GSM communication module
The MCU communicates with the GSM module through the RS232 ($780.5000) serial communication interface, extracts the short message of the GSM device, sends relevant information, and connects with the infrared module through the serial communication interface, and uses the infrared module to reach between the main and the extension. Communication, therefore, use the AT89S52 ($0.8482) chip. Two serial interfaces are required for control, but the 89S52 has only one serial port, so it is also necessary to perform analog serial interface communication in the program. The simplest external wiring circuit is shown in Figure 2.
Figure 2 AT89S52 external wiring
The 89S52 communicates with the TC35 via an asynchronous serial interface with a communication rate of 9 600b/s, with 1 start bit, 8 data bits, 1 stop bit, and no parity. After the MCU starts, it issues an AT+CMGD-2 command to clear the data in the second storage space, and then continuously issues an instruction to read the second storage space. If there is data, it means that the data is received, and the data is processed. After the processing is completed, the spatial data is deleted. When the MCU sends a short message to the mobile phone, the MCU will issue a series of AT, AT+CMGF=0, AT+CMGS=X commands to the GSM module. After receiving the reply message, the content of the short message is finally sent.
Infrared wireless communication module
The infrared transmitter circuit includes a 38 kHz crystal oscillator, an inverter, a NAND gate, a driving gate Q1, and an infrared transmitting tube D1 as shown in FIG. The 38kHz crystal oscillator, resistor R3 and inverter form a pulse oscillator to generate a 38kHz pulse sequence as the carrier signal. The infrared emitter D1 uses the TSAL6238 produced by Vishay to emit an infrared beam of 950nm.
Figure 3 Infrared transmitter circuit diagram.
Reset Lockout
Prevents reset if GFCI is damaged or failed to provide ground fault protection
Complies with NEC ® requirement, by blocking access to the contacts unless the plug is fully inserted
Only 1.22" Protrusion into Wallbox
Takes up to 20% less space in the wallbox vs. other GFCIs for easier installation
Multi-functional Status Indicator Light
Red and Green LED indications provide simple, intuitive feedback on power, voltage and protection status
Terminals Withstand
Tolerate high-torque;power tool installation;and prevents wire pullout
Tamper-Resistant Shutter mechanism
TR GFCI UL,New Version TR GFCI UL,TR Socket GFCI Outlets,New VGersion GFCI with TR Receptacle
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