China laser pointer can be used to find the way

Have 20mV overload drive, the device has a maximum propagation delay of 12ns, and the clock and signal rate of 85MHz. For high-precision counts, signal to noise ratio must be considered, the role of high-speed comparators. Comparator must be set comparative level, and compare the level of the main reference is the voltage amplitude of the noise signal, compare the level should be higher than the voltage amplitude of the noise signal, but lower than the signal voltage level. Compare the power level (threshold) set as small as that, which can reduce system power consumption, but too small to filter out not noise, too much will extract no laser signal. Here will introduce a handheld type flashlight  green laser pointer    to you customers.
Are closely related to the intensity of the noise signal and the background light intensity, the higher the intensity of the background light, noise, higher level. Comparison filter, noise suppression of the maximum, backlight basic filter. In general, by setting the threshold to the initial identification. But how to set the threshold to extract the correct signal has a great impact. Typically, after a set threshold, above the threshold value, which may have the laser echo signal. The microcontroller STC89C51. The microcontroller is a very wide range in the actual application design using the microcontroller through the serial port used to transmit data. The microcontroller STC89C51 choice can use the serial download process, do not buy the more expensive the compiler reduces the cost.   laser pointer   will emits the visible green light.
In addition, the confidentiality is also very good. STC89C51 series MCU on-chip UART for serial communications; There are two SBUF, one for send buffers, one for the receive buffer. To complete the initialization of the serial data into the send SBUF, can be predetermined baud rate, data sent and received data can be read from the receiver SBUF data received. Computer Interface Modules chip select. Can be seen from the diagram of the computer interface module, the MAX232 chip. This is due to the receiver module the microcontroller STC89C51 needs and PC serial communication. And the light effect of   green laser     will be more obvious in the dark area.
Computer serial port RS232 level-10v +10 v, while the signal voltage of the MCU application system is 0 +5 v TTL level, is clearly the need for level translation between the two. Level conversion interface module, using a dedicated chip MAX232, MAX232 by Texas Instruments Incorporated (TI) introduced a chip compatible with the RS232 standard. The device is a dual-channel RS232 linear driver / receiver, which includes the two drives, two receivers and a voltage generator circuit to provide TIA/EIA-232-F level. The device line with TIA/EIA-232-F standard, each receiver will TIA/EIA-232-F level to convert 5V TTL / CMOS level. Therefore,  green laser pointer can be used to indicate the direction.
Each transmitter TTL / CMOS level conversion into level of TIA/EIA-232-F. The above detailed design for intelligent transportation vehicles in the laser gun, the composition of the hardware circuit, chip select, choice of reference available for intelligent transportation and the development and management of electronic police technicians. Practice has proved that the car the laser gun system designed not only technologically advanced, high measurement precision, cost-effective and simple structure and easy to use, practical, and will soon be widely applied.  china laser pointer  can be used to find the way.