High-speed counting port schematic diagram

The system expands two high-speed counting ports, one of which is used to record the speed of cotton strips on site, so that the length of cotton strips can be calculated, and the process parameters such as shift production, total production, and fixed length can also be calculated. Since the microcontroller P3.4 (To) port is the external input capture port of timer 0, the high-speed optical coupler HCPL0611 is used here to expand this port into a high-speed counting port . The principle of the high-speed counting port is shown in Figure 3. The other P3.5 (T,) port expansion is not used for the time being, and is prepared for the future. The input and output ports and the high-speed counting port are both isolated by optical couplers to enhance the anti-interference ability and make the system run stably on site. The two full-duplex enhanced UARTs also use high-speed optical couplers HCPL0611 to expand into two communication channels in the system, one of which is used as a multiplexed communication port. From the characteristics of P89C669, it can be seen that since it includes a non-volatile Flash program memory inside, it can be used for serial in-system programming (ISP). In-system programming (ISP) means that blank devices on a circuit board can be written with end-user program code without removing the device. Already programmed devices can also be erased or reprogrammed using ISP.