How to set the current system time of the development board through the development board console

The use of GPS positioning satellites, real-time global positioning, navigation system, known as the Global Positioning System, referred to as GPS. GPS navigation system is composed of the following: 1, the path guide: to guide the user along the planned path; 2, the human-machine interface: to provide a friendly interface to allow the user to interact with the system human-computer; 3, the wireless communication module: allows the user to exchange real-time information with the monitoring center and other departments; 4, the electronic map database: contains digital map information stored in a predetermined format, is the system software platform; 5, the development board console to set the current system time. Electronic map database: contains digital map information stored in a predetermined format, is the system's software platform; 5, map matching module: through the appropriate matching and identification process to determine the vehicle's location on the map; 6, path planning: according to the map database and real-time positioning information to help drivers plan their routes; 7, positioning module: through GPS, inertial navigation system or mobile communications and other methods for vehicle location; 7, positioning module: through the GPS, inertial navigation system or mobile communications and other methods for vehicle location. or mobile communication and other methods to locate the vehicle. Combined with the actual hardware and software structure, this system is divided into four layers: the bottom layer is the hardware platform layer, which contains the ETX embedded CPU module and the necessary sensors/sub-modules. The upper three layers are software layers, in which the device driver layer acts as a bridge between the hardware platform and the operating system, providing a unified interface for the upper layer independent of hardware devices; the Android system layer provides library functions, application program interfaces, task scheduling mechanisms, etc. to provide support for the user's program; the application software layer is the user's self-developed program, which mainly includes the electronic map and navigation applications, and is also the core part of this system. It is also the core part of this system. The following is an introduction to the system from the hardware and software aspects. First, the system hardware Exynos4412 is the current popular Samsung quad-core processor, has been widely used in consumer electronics, industrial control, medical equipment, instrumentation and other industries. Its powerful performance and excellent stability has won wide acclaim in the embedded industry. The following is a brief introduction to NXP's low-power single-chip GNS7560A-GPS solution. NXP GNS7560 is a compact, very low power consumption, and very low system cost GPS solution. It uses 90NM process architecture, including a high-performance CMOS RF front-end and correlator engine, greatly reducing the system cost and power consumption. Advanced power management modes reduce map update power consumption to 13mW per second, significantly lower than other GPS solutions. with an external package size of less than 9mm2, the GNS7560 is the smallest GPS chip available, and when integrated with NXP's cellular solution, the 7210, it is the smallest overall solution. Unlike other GPS solutions, the GNS756 automatically adjusts tracking sensitivity based on signal strength, multichannel and rate, providing best-in-class acquisition and tracking sensitivity and time to first fix (TTFF), even in densely populated urban areas such as the so-called urban canyons (urbancanyon), to ensure indoor depth (deep-indoor) sensitivity and reliable coverage accuracy. The GNS7560 communicates with the processor 4412 through the serial port to transmit the searched satellite signals and time and other information to the processor, the corresponding circuit schematic diagram is shown below: In the antenna side needs to increase the LNA (Low Noise Amplifier current), as shown in the figure: In order to increase the signal strength and inhibit the interference of stray signals, it is best to increase the acoustic surface band pass filter, principle As shown below: In this way, the processor 4412 can work properly with the GPS chip. In practical applications, hardware PCB wiring and anti-interference shielding is a special concern. Here combined with the actual debugging experience, give a few suggestions, I hope to bring you some help: 1, the antenna is divided into active and passive antenna two kinds. For active antennas, you need to increase the power supply in the circuit, through an inductor connected to the antenna side, so that you can give the active antenna power supply. It should be noted that when using an active antenna, the circuit schematic can remove the LNA circuit, because this part of the circuit already exists in the antenna. 2, in the PCB wiring must pay attention to the 50 ohm impedance design, which has a great impact on the strength of the antenna signal.3 For the GNS7560, as well as the LNA and filtering circuits, it is best to be placed in the shielding and away from the digital signal area to prevent signal loss caused by circuit interference. Second, the system software for android system, GPS software architecture is as follows: header file is defined in: hardware/libhardware/include/hardware/gps.h, defines the GPS underlying related structures and interfaces. Test the entire system, you can open the android supporting test software, the following chart: