Video intercom access control system

What are the modules of the video intercom access control system? Video intercom access control system communication module circuit diagram design. For visual intercom access control, understanding the system configuration can be more familiar with the entire module composition. Among them, the most important is the video intercom access control system communication module, which is the core of the video intercom access control system and plays a very important communication role. This chapter mainly introduces the circuit diagram of the communication module of the visual intercom access control system. WxI Smart Lock China

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Video intercom access control system design ideas: Buildings under the door to set up a video intercom access control switchboard, you can call all units of this apartment building resident, the owner through the visual access to confirm the identity of visitors after the decision whether to open the door. WxI Smart Lock China

The technician will set the number of effective digits when setting up the unit's door machine, ie it will be valid for a few digits at the door. Visitors can just press a few digits and press the call or # key. Of course, the technician usually omits the building number and the unit number, which is more convenient to use. WxI Smart Lock China

Video intercom access control system main application and residential building, video intercom access control system communication module to the microcontroller as the core of the control, microcontroller chip generally use AT89C51, through the pin to connect peripheral circuits, the use of wireless digital transmission circuit to achieve short-distance video signals Transmission, transmission range of 50 ~ 200m. The video intercom access control system communication module can obtain continuous display of images on the basis of a single shot, thereby achieving the purpose of wireless digital transmission of image signals. WxI Smart Lock China

The operating principle of the main control chip AT89C51 of the video intercom access control system communication module is as follows: WxI smart lock China

1. The visitor enters the room number accessed through the keyboard and confirms the call. The microcontroller AT89C51 controls the video acquisition chip and the buffer chip to work. In the case of the set communication baud rate, the data is sent by the microcontroller through the serial port communication. To the digital transmission circuit, the digital transmission circuit transmits the data through the wireless channel. WxI Smart Lock China

2, from the controller's main control chip also uses AT89C51, through the digital transmission circuit to receive the main controller's control information and data information, the received data is classified, if the host sent over the communication address signal, from the controller will read Take the data in the ringing tone storage circuit so as to give a ringing tone. Then the video signal is received and displayed on the LCD display circuit. The user can determine whether to make a further call with the master controller through the key control circuit. WxI Smart Lock China

The main controller circuit is composed of a single chip AT89C51, a keyboard scanning circuit, a drive and a digital display circuit, a watchdog circuit, and a wireless data transmission circuit. The hardware schematic of the main controller system is shown in the figure below: WxI Smart Lock China

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The working principle is as follows: first, scan the user's key information through the keyboard scanning circuit to obtain the slave's communication address, and display the key information through 4 LEDs so that the user can clearly know the slave address he wants to access. The user can confirm the modification of the input value by adding value, decrement, and retransmission on the keyboard. When the user presses the confirmation key, the host computer stores the slave address at this time, and turns on the video chip to sample the video signal, and at the same time sends the slave address through the wireless digital transmission chip SRWF. After receiving the slave's response signal and ready signal, the master starts sending data at the set baud rate. Each frame sends data waiting for the slave's reply signal, and sends a check frame for each frame of data at the same time to ensure the accuracy of data transmission. WxI Smart Lock China

The sub-controller also uses the AT89C51 microcontroller as the microprocessor. The peripheral interface circuit of the sub-controller system consists of a crystal oscillator, an LCD image display circuit, a key unlocking circuit, a watchdog circuit, a communication interface circuit, and a memory. The hardware circuit diagram of the sub-controller system is shown in the figure below: WxI Smart Lock China

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The working principle of the circuit: Initializes its receiving baud rate, and is in the state of information monitoring all the time, when receiving the address frame, it is compared with its own address, if different, discard this frame data and continue to measure. If the same, then read the music code stored in the AT24C02 chip, and control the horn to send the melody tone through the P2.1 port, so as to tell the user that there is a visitor requesting to enter the building. WxI Smart Lock China

When the user presses the answer key on the keyboard, the MCU will send the data received from the wireless digital transmission module to the P0 port for liquid crystal display. When the homeowner sees the image on the LCD, if he knows the visitor, press the key to unlock it; if he does not know the visitor, press the hang key to end the video call. The main working chip of the video display circuit is the TFT6448B. The TFT6448B has its own data latch and does not need to extend the latching chip. After selecting the TFT6448B, data can be written to the corresponding row, column, control, and data registers of the TFT6448B, and the control display of the microcontroller AT89C51 to the TFT6448B can be realized. WxI Smart Lock China

The above is a picture of the video intercom access control system organized by the smart lock China Network Xiaobian. It mainly provides the circuit diagram of the communication module of the video intercom access control system. For more information on the principle of the smart lock, please pay attention to the related introduction of this site. WxI Smart Lock China