The power of green laser pointer

The module also supports the three-wire serial port, only need to connect the SIN and the SOUT two signal line and ground in this manner, microcontroller modules, microcontroller through the serial port to send two preamble bytes (57H, ABH) to replace the original start signal to the STA # pin of the module, synchronization with module command. Two preamble bytes through the serial input, the module will check the serial data input timeout, if the interval between two consecutive data bytes greater than the serial input timeout, the module will give up the preamble and the command packet . 3.4.2 interface chip CH375 (1) an overview of the CH375 is a USB bus interface chip, and supports both USB-HOST mode and USB-DEVICE/SLAVE the form of equipment.  green laser pointer is the handheld devices.
Locally, CH375 8-bit data bus and read, write, chip select control lines and interrupt output can be easily attached to the system bus of the MCU / DSP / MCU / MPU controller. In USB host mode, CH375 provides a serial communication via the serial input, serial output, and interrupt the output and the microcontroller / DSP / MCU / MPU, etc. connected. CH375 is a USB host to support USB full-speed device, external MCU through CH375 in accordance with the USB protocol and USB device communication. CH375 also built a dedicated communication protocol processing Mass.-Storage Mass Storage device firmware.  green laser pointer  simplifies the multimedia teaching process.
External microcontroller can read and write directly to the sector as the basic unit of USB storage devices. CH375 chip can work in both USB-HOST mode or USB device mode. CH375 is a USB host to support the parallel interface and serial interface. In USB host mode, CH375 supports USB full-speed device, external microcontroller need to write firmware in accordance with the USB protocol and USB device communication. USB storage devices, CH375 built-in the relevant agreement, Under normal circumstances, the external microcontroller does not need to write firmware, you can communicate directly. 12 (2) serial interface serial interface can only be used for USB host mode, CH375 is the chip USB device does not support the serial. Each set of  green laser pointer  owning its unique ID code.
The serial signal lines include: RXD serial data output pin TXD, the INT # interrupt output pin. Through the serial interface, the CH375 is connection with the MCU, the DSP, the MCU than the long-distance point-to-point connection. Of CH375 RXD and TXD are connected to the microcontroller serial data output pin and the serial data input pin. The INT # output the interrupt request is active low, used to notify the MCU. CH375 serial data format is 1 start bit, nine data bits, 1 stop bit, 8 data bits in which the first byte of data, and finally a data command flag. 9 to 0:00, 8 data is written of CH375, 9 to 1:00, the first eight as the command code is written of CH375.  green laser pointer  won’t interfere with other laser pointers.
CH375 serial communication baud rate default is 9600bps, the microcontroller can select the appropriate communication baud rate at any time by SET_BAUDRATE command. Figure 3.8 CH375 is the serial port connection diagram in the P3 port is to connect the module port. Because it is a serial connection, connect the signal line less, and only requires three signal lines: SIN, SOUT, and STA # module interrupt line INT # is optional, if the interrupt notification, it can be connected to INT0 or INT1 Otherwise, without having to connect the INT # signal line modules. Proposal with reference to the diagram, the module 14-pin port (parallel CS # pin) is connected to VCC, to avoid the parallel port is selected. Within the internal structure of the CH375 chip integrates a PLL frequency multiplier.  green laser is convenient for users to carry with.