Top1 automobile anti theft system module circuit based on fingerprint identification

Main working principle: after the car owner stops, the burglar alarm enters the locking state. At this time, if the car key is not on, fingerprint identification can not be carried out; Only when the car key is on can fingerprint identification be used to unlock the anti-theft device and ignite automatically. In the locked state, the oil circuit and electric circuit of the car are cut off, and the car key cannot be ignited; If you forcibly cut the connection between the fingerprint acquisition module and the control box, or if you forcibly use the car key to ignite the car without identifying the fingerprint, the car will alarm through horn, flashing light and wireless communication network. When the password key is inserted in the locked state, it can enter the unlocking state. According to the LCD and voice prompt, fingerprint registration / deletion, mobile phone number setting and emergency ignition can be carried out through the small keyboard.

  USB interface circuit

The USB interface circuit is mainly implemented by the file management control chip ch376t. Ch376t supports USB device mode and USB host mode, and has built-in basic firmware of USB communication protocol, firmware of special communication protocol for mass storage device, firmware of communication interface of SD card, firmware of FAT16 and FAT32 and FAT12 file system management, Support common USB storage device and SD card. Ch376t supports two communication interfaces: SPI interface and asynchronous serial port. This design uses SPI interface to communicate with MCU. The circuit connection mode is shown in Figure 2. Serial data input SDI, output SDO and clock SCK are connected to SPI1 of stm32f103vc respectively_ MOSI,SPI1_ Miso and SPI1_ SCK, interrupt request output int connected to PC0, chip selection end SCS controlled by PA1. The reset signal in the figure is the system reset signal, and the crystal oscillator Y1 selects 12 MHz. When the vehicle mainly carries out fingerprint registration / deletion or emergency ignition, access the password key (U disk) to J1 to read the password information.

  Circuit design of automobile anti theft system based on fingerprint identification

  Voice circuit

The schematic diagram of voice circuit is shown in Figure 3, which is composed of isd4004-16 of ISD company and LM386 of national semiconductor company. Isd4004-16 recording and playback time is 16 min (segmentable). It uses CMOS technology, single power supply 3 V operation, including oscillator, anti aliasing filter, smoothing filter, audio amplifier, automatic silence and high-density multi-level flicker memory display. It has SPI bus serial communication interface. The analog voice data can be directly written into a single memory unit without a / D or D / a conversion. ISD voice circuit has many advantages, such as natural sound quality, easy to use, single-chip storage, repeated recording and playback, low power consumption, power-off resistance and so on. LM386 has wide working voltage range and adjustable voltage gain. It has the characteristics of low power consumption, adjustable voltage gain, wide power supply voltage range, few external components and small total harmonic distortion. In this design, stm32f103vc transmits voice information to ISD4004 through SPI2. V1 and V2 in Figure 3 are respectively connected with + 3.3 V and + 12 V power supply through triode. The on-off of triode is controlled by pci1 and PCI2 of stm32f103vc. Only when voice prompt is required, can triode be connected to ISD4004 and LM386 for power supply.

  Circuit design of automobile anti theft system based on fingerprint identification

  Circuit module of optical fingerprint identification system based on ARM

The whole system consists of an integrated optical fingerprint identification module. The module design adopts the principle of optical dark background imaging, and adds a unique living detection chip to solve the dry finger effect and the problems of residual fingerprint misidentification and rubber false fingerprint. The figure shows the application circuit diagram of optical gc0307 CMOS image acquisition chip. The CMOS image acquisition chip is a built-in component of a high-performance camera with high precision, low power consumption and micro volume. It combines CMOS image sensor for high-quality VGA image with highly integrated image processor, embedded power supply and high-quality lens set, outputs JPEG image or image video stream, and supports 8 / 10 bit digital transmission of JPEG image and YCbCr interface, Provides a complete image solution.

  Circuit design of optical fingerprint identification system based on ARM

CMOS image acquisition core function output serial data pin, clock signal pin, reset pin and serial bus pin are connected to the GPIO port of stm32f205re, and the image information collected by CMOS chip is read through GPIO port to simulate timing. Because the working frequency of GPIO port of stm32f205re can reach 120 MHz, it can simulate the timing accurately and efficiently, and measure 640 MHz × 480 of the original image can be collected at the speed of 10 frames / s to the main processor stm32f205re for image processing.

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