Specific realization function
The system is composed of STC89C52 single-chip microcomputer + UBLOX-NEO-6M GPS module + LCD screen 12864 + power supply + LED indicator module.
Specific functions:
It can automatically calibrate and display data such as time, latitude and longitude, speed, heading, altitude and altitude with the 12864 LCD display.
design background
GPS is the abbreviation of English Global Positioning System (Global Positioning System), and its Chinese abbreviation is "ball position system". GPS started as a project of the US military in 1958 and was put into use in 1964. It is a new generation of space satellite navigation and positioning system jointly developed by the United States Army, Navy and Air Force in the 1970s. Its main purpose is to provide real-time, all-weather and global navigation services for the three major areas of land, sea and air, and for military purposes such as intelligence collection, nuclear explosion monitoring, and emergency communications. After more than 20 years of research and experimentation, at a cost of 30 billion U.S. dollars, by 1994, 24 GPS satellite constellations with a global coverage rate of 98% had been deployed. With the development of people's living standards, GPS technology is increasingly used in personal PDAs, personal vehicle terminals, mobile phones and other devices. Through GPS, people can accurately know where they are, from realizing to navigation, determining travel routes, and obtaining geographic information. The GPS navigation system introduced in this article uses a single-chip microcomputer as the main control chip, coupled with GPS and 12864 display screens, to build a GPS information display system. This system has promoted the development of GPS navigation equipment research to a certain extent.
hardware design
GPS is a navigation satellite ranging, timing, positioning and navigation system developed by the US Department of Defense. It consists of 21 working satellites and 3 standby satellites in orbit. The GPS system consists of 3 parts:
One is the GPS satellite (space part), which consists of 21 working satellites and 3 spare satellites;
The second is the ground support system (ground monitoring part), consisting of 1 main control station, 3 injection stations, and 5 monitoring stations;
The third is a GPS receiver (user part), which receives signals from GPS satellites to obtain necessary information.
The satellite continuously sends its own parameters and time information. The GPs receiver receives the data containing time information in the signal transmitted by the satellite. These data are transmitted to the single-chip or computer through serial communication, and the accurate time information can be obtained after analysis and calculation. In addition, the receiver has an output terminal dedicated to output a 1pps signal, the rising edge of which corresponds to the UTC time output by the receiver's serial port, with an accuracy of 1|us, which can be directly provided to users who need time calibration, or can be combined with the UTC output of the serial port. Always work together on the microcontroller or computer to obtain a more accurate time.
The hardware used in this system is mainly composed of 51 single chip microcomputer, liquid crystal display module, GPS module and some peripheral circuits.
software design
After the main program of the system starts, first initialize the system environment, including setting the serial port, timer, interrupt, and LCD1602 initialization; then the LCD screen enters the power-on state, displays the power-on information (LCD_log), switches to the normal display, and receives data , Two strings of characters are displayed at a time. Then because the single-chip microcomputer does not have a stop command, the system program can be set to continuously execute the data information display in a loop.
The system program structure belongs to the interrupt mode, and most of the functions are completed in the interrupt service subroutine. According to the overall structure, the program can be divided into several functional modules: serial port interrupt service routine, display subroutine, scanning program. Each module can be independently designed, debugged and checked for errors, and finally connected into a whole.
Schematic diagram
The system schematic design adopts Altium Designer19, as shown in the figure.
program
This design uses KEIL5 software to realize the program design, as shown in the figure.
Simulation implementation
This design uses protues8.7 software to realize the simulation design, as shown in the figure.
All information
All materials include programs (notes), AD schematics, PCB source files, protues simulation, reference papers, program explanations, simulation explanations, simulation videos, schematic explanations, introductions to the use of materials, etc., the most complete network!
