Design of Vehicle Navigation System Based on ARM9-Linux Platform

Design of Vehicle Navigation System Based on ARM9-Linux platform 14:26:33

1. Preface
Near
Over the past few years, with the rapid development of the national economy and the increasing living standard of the people, the number of motor vehicles has increased dramatically and the demand for vehicle navigation systems has also increased dramatically. This article uses
ARM9-Linux platform embedded system as the system control platform, improve the system performance, integration and scalability; using GPS positioning technology and advanced GPRS
The wireless communication technology is combined to realize vehicle electronic map navigation and short message alarm.
The module design enables flexible display of various vehicle information, enriches the human-computer interaction interface, and makes the system more intelligent. The vehicle GPS
The navigation system is the Intelligent Transportation system (ITS, Intelligent Transportation
System) is an important branch for solving urban traffic problems.
2. GPS Global Positioning System (1)
GPS (Global
Positioning System) the System consists of three parts: the Space part-satellite constellation, the ground control part-the ground monitoring System and the user equipment part-the signal receiver. GPS
With the development of modern science and technology, the Global Positioning System is a high-precision, all-weather and global radio navigation and positioning, timed multi-function system. It uses
A-kilometer-high satellite network composed of 24 satellites, continuously transmitting positioning signals to the Earth. Any GPS on the earth
Receiver, As long as any four or more satellite signals are received, after calculation, the GPS receiver's location (longitude, latitude, height), time, motion status, and other information can be obtained. GPS
The system features high precision, around the clock, high efficiency, multi-function, simple operation, and wide application.
3. Overall System Design
The system provides Vehicle Navigation and mobile-based vehicle anti-theft.
The entire system consists of two parts: the first is the car owner's mobile phone, and the second is the car-mounted part. The mobile phone is only a mobile phone used to send and receive short messages. The vehicle-mounted part mainly provides the Vehicle Volume positioning and navigation functions. The on-board part has two types of work
Mode: The first mode is the "driving mode". In this mode, the car owner can easily use the human-computer interaction interface of the vehicle navigation system to navigate the car; when the car owner needs to leave his car, press"
Safe Mode "key to start the second working mode. After starting this mode, the system constantly uses the GPS Positioning Technology to determine whether the current location of the vehicle has changed. If someone steals a vehicle, the location of the car behind the car
When the system detects that the longitude and latitude of the vehicle position change, the system sends a short message to the car owner in real time through the GPRS network to report the current location of the car.
4. System Hardware Design
The hardware of the system is mainly composed of the main control module and the expansion module. The expansion module mainly includes the GPS module, the LCD module, and the GPRS module. The structure diagram 1 of the system hardware is shown below:

4.1 design of the master control module (2)
Master
The control module design is the core of the hardware design. It mainly includes power supply circuit, clock circuit, reset circuit, storage module circuit, JTAG interface circuit, serial port circuit, LCD interface, SPI
Interface and key circuit design. This article uses Samsung's S3C2410 processor, the main control module through the serial port, SPI interface, LCD
Interfaces are connected with the extended modules to form the entire hardware system.
4.2 GPS module selection
The GPS module receives and processes GPS positioning information. The GPS25-LVC receiver of Garmin company is selected. The OEM interface signals of gps25 are shown in table 1:

4.3 GPRS module selection
The GPRS module can be used for wireless communication, including voice communication, sending and receiving short messages, and wireless Internet access. In this system, mc35 is used to complete the short message function. The hardware connection 2 is shown below:

 

5. Software Design
The hardware of the on-board navigation system lays a solid foundation for the implementation of basic functions and extended functions. The design of the software system is to make full use of the resources provided by the hardware platform, implementing the orderly operation of business processes is an important part of the system design. The software design mainly includes (3 ):
(1) Establish a cross-compiling environment; (2) transplantation of bootloader; (3) transplantation of Linux operating systems including drivers; (4) Program Design of GPS positioning module; (5) GPRS Communication Module Program design; (6) display interface design. The above interface design is implemented based on MiniGUI;
5.1 GPS module software design
GPS
The module collects, processes, and stores vehicle location information. Because GPS uses serial port communication, this paper implements
Receives, processes, and stores data. The basic idea of software design for this module is as follows: first, it receives the complete nmea0183
Statement, and then extract the relevant data, such as time, latitude and longitude, speed, and so on, then send the data to display or send it out, and save it for future viewing.
The system selects GPS25-LVC
The nmea0183 statement output by serial port 1. Format: $ gprs mc, 082 004, A, 3990.347 2, N, 11 953.099 0
E, 000.0, 000.0 130 807 002.5, w * 71, indicates that the current time is August 13 08:20:04 (this is UTC
Time, not the local time, the difference between the two is about 8 hours), the location is 39 degrees 90.347 2 points north latitude, 119 degrees 53.099 0 points east longitude, the speed is O.
5.2 Software Design of GPRS wireless communication module
In software control of the mc35 module, the standard V.25 ter at command is mainly used, and the related AT commands used in system development are shown in Table 2 (4 ).

The specific execution process of the AT command is as follows:
At
OK
At + csca = + 8613800773500/R
OK
At + cmgf = 1/R
OK
At + cmgs = + 861348137... /R
> Your car is being stolen! /X1a
+ Cmgs: 206
OK
In
When the alarm function is run, after the above steps are completed, the alarm short message is sent, and the owner's mobile phone will receive a text message with the content "your car is being
Stolen !". Then, the mc35 module reads the current location in real time in the corresponding storage area under the control of the MCU, and reports it to the car owner continuously in the form of short messages to help the car owner and the Police Recover the car
Vehicles.
5.3 software design for interface display (5)
Embedded applications are developed on a host machine (such as a PC). embedded applications are debugged and run on the host machine, and then embedded applications are compiled.
Translate the link into binary target code that can be run on the target platform. Because the MiniGUI library is used, the MiniGUI library must be compiled and linked to a binary target code library that can be run on the target platform.
The development process ends when a MiniGUI application is deployed on the target platform and runs reliably. The positioning information interface displays the location and other information of the vehicle received by GPS, and then expands the electronic map
This information is displayed more intuitively. Figure 3 describes
MiniGUI software development process:

6. Summary
Innovation points of this article: 1) the on-board navigation function is designed and implemented on the arm-Linux platform. The system features low cost, low power consumption, high processing performance, and good stability. 2) This platform facilitates system software and hardware upgrades.