Application of wireless communication module with GPS to create a car positioning and tracking system
When people buy a new car nowadays, in addition to the performance of a car, I am afraid that more consideration is the safety and comfort of the car. In addition to airbags, ABS, ESP and other safety features provided by the car itself, car diagnostics, car anti-theft, location tracking and other real-time online services are also very important. Meanwhile, entertainment services for passengers centered on in-car multimedia are also part of the customer's consideration.
Simply put, wireless services used in automobiles can be broadly categorized into two types: 1) location tracking; 2) in-vehicle multimedia.
1) Location tracking
Location tracking should be the most basic demand, many applications are built on this function, such as car navigation, car diagnosis and so on. For chartered buses engaged in tourism, more than three levels of buses and the transportation of dangerous goods “ two guests and a dangerous ” vehicles, the state has also introduced relevant regulations, requiring such vehicles must be mandatory installation of satellite positioning devices, in order to real-time monitoring of the operational status of such vehicles.
Automotive diagnostics (such as OBD) and special vehicle tracking and automotive anti-theft functions require vehicle-mounted equipment to first obtain location information before uploading to the data center. We are not unfamiliar with the technology to realize the positioning function, such as China's establishment of the Beidou satellite navigation system and the United States of America's GPS system can achieve accurate positioning. There are various ways to upload data to the data center, among which the reliable and economical way is to rely on the cellular network with wide coverage.
There is a GPRS+GPS tracking and positioning solution in the market. Figure 1 shows the system architecture of this solution. For the tracking and positioning solution applied to automobiles, firstly, the on-board equipment of the automobile obtains the position data and gravity sensing data (to determine whether the automobile is safe or not), and then uploads these data to the designated server with the help of GPRS to realize real-time tracking and anti-theft functions. At the same time, the background can also be sent directly to the user through the GPRS network SMS or voice data to prompt or warn the driver, this feature for & ldquo; two passengers and a dangerous & rdquo; vehicles can be said to be very useful.
In terms of specific implementation, the market provides a variety of products to support this program. Its GSM/GPRS series, WCDMA/HSPA series, and LTE series all have products that can realize this kind of function, however, if you only need to realize the basic function, then you can reach it by using the A8900 in the GSM/GPRS series.
A8900 is a quad-band GSM/GPRS module with integrated GPS navigation technology, adopting advanced and highly integrated design scheme, integrating GSM/GPRS and GPS RF and baseband on one PCB, and completing the functions of wireless receiving, transmitting, baseband signal processing, and audio signal processing.A8900's GPS service supports 56 channels, and the sensitivity of tracking and navigation can reach -162dBm. The GPS service can support 56 channels, and the sensitivity of tracking and navigation can reach -162dBm, the cold start time of the first positioning is 26s, and the hot start time is 1s. As for the GSM/GPRS part, the A8900 can work in the GSM850/EGSM900/DCS1800/PCS1900 bands, and it supports the GPRS multi-timeslots class 12 and the CS-1, CS-2, CS-3, and CS-4 coding schemes.
A8900 adopts LCC package with single-sided layout, the size is only 35mm×25mm×2.7mm, which can realize the rapid production of modules through SMT equipment, and provide customers with highly reliable connection, especially suitable for automation, large-scale and low-cost applications.
2) In-vehicle multimedia
As for entertainment, in addition to local entertainment, the car can also access the Internet through 3G and 4G networks to obtain more entertainment resources.
U9300C is the LTE series in the market, which can work in LTE-TDD/LTE-FDD/TD-SCDMA/UMTS/EVDO/EDGE/GPRS/GSM/CDMA/GPS and other systems. Under LTE-TDD/LTE-FDD system, U9300C uplink and downlink rates can reach 50Mbps and 150Mbps. In addition, U9300C also supports GPS/BeiDou navigation and positioning function, which supports at least 44 channels, with a positioning accuracy of less than 10m and a tracking sensitivity of -162dBm, with a cold-start and hot-start time of 60s and 1s, respectively.
