The main thing about GPS navigation: what is a GPS module and its functions? What is GPS in a tablet and what can it do?

Today, Russian developers have access to several dozen built-in GPS modules from various manufacturers. He only needs to choose the receiver that will satisfy his requirements for sensitivity, price, design, etc. But in order to make the right choice, you need to monitor the market situation, new products and development trends. The article contains information about the latest developments by EverMore in the field of OEM GPS solutions.

About company

EverMore, a Taiwanese company, has focused exclusively on GPS products since its founding in 1998. Over the 10 years of its existence, it has managed to accumulate decent experience and acquire a significant nomenclature. This is one of the few GPS product manufacturers that has its own chipset. The company's activities include the production of chipsets, embedded GPS modules, data loggers, and complete personal navigators. By developing its own technologies, EverMore keeps up with the times and uses the best developments in the field of GPS in its products. In addition to its own chipset, the company uses such advanced technologies as Sirf Star III, Antaris 4, Nimerix. This approach provides EverMore products with very broad capabilities and allows them to compete with GPS market leaders, as well as meet the needs of the most specific navigation tasks. Thanks to this, despite being little known in Russia, the company has a large number of clients in Southeast Asia, Europe and the USA. At the same time, the quality of the products, as well as the production process, including development, assembly and testing, are marked with ISO 9001/14001, QS-9000 certificates.

EverMore and ANTARIS 4

The company recently introduced new OEM modules: EB-A801 and EB-A802-P. Their appearance is shown in Figure 1.

Rice. 1.

These modules are based on the ANTARIS 4 chipset, developed jointly by U-Blox and Atmel. ANTARIS 4 is the core navigation signal processing technology. It provides excellent navigation performance in all conditions, including areas with limited sky visibility or areas with poor signal strength. At the same time, the accuracy of determining coordinates is maintained at the same level. This is achieved by using a large number of correlators that process received signals in parallel, as well as a special integration algorithm. Among other things, the ANTARIS 4 chipset has a built-in temperature-compensated crystal oscillator (TCXO) on board. All this allows you to receive and process data at a signal level approaching -159 dBm. In addition, ANTARIS 4 provides very low power consumption. This fact makes devices based on this chipset extremely attractive for various types of stand-alone applications, where the cost-effectiveness factor is the determining factor in most cases. The ANTARIS 4 chipset includes a set of chips. It includes a low-noise input signal amplifier, a radio signal receiving and processing chip, and a group signal analyzer chip. The presence of such a configuration allows you to create complete, small-sized GPS modules that do not require additional external elements. Figure 2 shows the typical architecture of a GPS module based on ANTARIS 4 technology.

Rice. 2.

Module features

Based on the above, we can conclude that the EverMore EB-A801 and EB-A802-P modules, based on the ANTARIS 4 chipset, have all the advantages of the technology. Due to the fact that the modules include a low-noise input signal amplifier, they are able to work with both active and passive antennas and show excellent performance. A big advantage is the presence of a built-in USB port. This eliminates the need for an expensive serial-to-RS-232 or serial-to-USB converter, making the modules plug-and-play compatible with any PC environment.

The consumption of EB-A801 and EB-A802-P modules is very low. It is only 39 mA. This parameter can be reduced even further by supporting the FixNOW function. When this function is enabled, the module turns off when the GPS signal is lost and turns on at specified intervals to make repeated attempts to “capture” signals from the positioning system satellites. In addition, it is possible to force the module to turn off and on when there is a good signal. This is useful in cases where frequent determination of coordinates is not required. Thus, it is possible to reduce the receiver consumption to 80 μA and increase the battery life of the device.

The EB-A801 and EB-A802-P modules do not require additional initialization. GPS data is transferred immediately after switching on. Support for the special binary protocol UBX allows you to configure the operating modes of the output ports, the types of messages issued, receive “raw data”, enable the fast “capture” mode or the increased sensitivity mode. Both modules provide a high-precision pulse per second (1 pps) synchronized with Universal Time Coordinated (UTC).

The peculiarity of ANTARIS 4 technology is such that modules based on it do not require additional external elements. A typical connection diagram for the EB-A802-P module in a minimal configuration is shown in Figure 3. For its operation, it is enough to connect the antenna, microcontroller and supply power. If an active antenna is used, power must be supplied to the designated terminal.

Rice. 3.

An interesting feature of the modules is support for SBAS (satellite subsystem for differential service) technology. This subsystem includes several technologies: WAAS, EGNOS, MSAS. All of them are supported by modules. The purpose of SBAS is to increase the accuracy of determination using differential corrections transmitted through a network of geostationary satellites. These satellites transmit signals on the L1 frequency, on which all GPS satellites broadcast. This system allows you to increase the accuracy of determining coordinates up to 2 meters.

In general, the parameters of the EB-A801 and EB-A802-P modules are the same. They are shown in Table 1. The main difference is the smaller size of the EB-A802-P and the presence of a built-in EEPROM. This allows you to save data and configuration of the receiver when the power is turned off, and, if necessary, update the software.

Table 1. Basic technical characteristics of GPS modules from various manufacturers

Comparison of EverMore modules with other popular GPS receivers

To compare the capabilities of the EB-A801 and EB-A802-P EverMore modules, we will consider the basic technical characteristics of GPS receivers from leading Russian manufacturers. Antaris 4 chips are used by many manufacturers of GPS modules. First of all, this is the U-Blox company, one of the creators of this technology. The technical parameters of the most popular model LEA-4H are shown in Table 1. The modules have all the advantages of the technology: high sensitivity (-158 dBm): low power consumption, the ability to work with both active and passive antennas. The accuracy of determining the coordinates is 2.5 meters with a confidence level of 50%. LEA-4H also has a built-in USB port. Another popular technology is SiRF Star III. This chipset is used by manufacturers such as Tyco and Leadtek. Table 1 shows the technical parameters of GPS receivers based on SiRF Star III. These are LR 9548S from Leadtek and A1080-A from Tyco. These modules have excellent sensitivity (-159 dBm). Reception is carried out on 20 channels. Thanks to a larger number of correlators, these modules are able to detect a signal faster. The hot start time is only 1 second. However, their consumption is slightly higher than that of U-Blox and EverMore modules. Although it must be said that the A1080-A module from Tyco itself consumes only 36 mA. But it can only work with an active antenna (just like the LR 9548S from Leadtek), the consumption of which reaches 50 mA. As a result, total energy consumption increases. The lack of a USB port from both manufacturers can also be considered a disadvantage.

Having compared the basic technical characteristics of modules from EverMore with products from leading GPS manufacturers, we see that they are in no way inferior to the favorites. And they may well replace them. At the same time, they turn out to be cheaper than their famous counterparts. It should be noted that the EB-A802-P module is pin-to-pin compatible with the popular LEA-4P from U-Blox. But with sensitivity like LEA-4H.

In conclusion, EverMore's EB-A801 and EB-A802-P modules offer features that make them ideal for a variety of offline, automotive and personal navigation applications. Ease of inclusion, miniature size and absence of external elements can significantly reduce financial and time costs for creating the final product. The features of the miniature design allow for both automatic and manual installation, which is applicable in small-scale production. Combined with an affordable price, the EB-A801 and EB-A802-P modules from Ever More are the best choice for those who want the best technical characteristics at minimal cost.

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Ultra-low consumption GPS module

Company EverMore announced a new GPS module EB-E36-LP, consuming only 16 mA! The EB-E36-LP is a single-board 12-channel GPS receiver designed for OEM portable marine and land navigation solutions that require good performance at low cost. The receiver operates in the temperature range from -40 to 80°C and has dimensions of 45x31 mm. A special version of the GPS module for aviation applications allows you to issue coordinates with a frequency of 5 times per second. EB-E36 GPS modules are based on EverMore's own chipset.

About EverMore Technology

Articles and Lifehacks

Interesting, what is gps in a tablet, a miniature portable computer that has become a part of our lives? For modern people, it has already become commonplace to use all kinds of devices with a GPS chip in everyday life. Such devices include: trackers, phones, navigators, etc. Thanks to improvements in the production technology of these devices, GPS modules are becoming much cheaper. They are used in cameras and video recorders, including camcorders.

Features of GPS built into a tablet computer

Such a global positioning system (GPS) allows one to determine with sufficiently high accuracy the location of both stationary objects and objects in motion in three-dimensional space.

The domestic market reacted positively to the emergence of devices of this class. Recently, there has been a tendency to combine a tablet computer and a navigation system for cars. According to the manufacturers, the vocation of such a “combine” is the development of tablet computers, introducing features of a navigation system and a video recorder. Let's figure out what GPS is in a tablet. Studying the characteristics of a tablet with a GPS module, we understand that it is capable of receiving signals from navigation satellites. Consequently, when cards are uploaded to the tablet, it can process the information coming from the module, i.e. serve as a navigator.

The average person can use such a device not only in a car, but also at home, at the workplace or on vacation. This device, which provides a wide range of capabilities, is an excellent assistant because it makes the user’s life much easier. The advantage of car tablets is a convenient location of buttons and a compact screen.

What can a GPS tablet do?

Developing the tablet computer market, Japanese manufacturers tried to integrate a GPS chip into the tablet, but this led to a significant increase in the price of the device. However, such computers have become widespread among users. With such a popular device you can: read books in electronic form, watch movies, play games, listen to the radio (music), work on office programs, and also use the DVR and navigator functions. In addition, you can go online anywhere where there is GPS coverage from the operator, and also send mms or sms.

You can make a video call via GPS (although not of sufficient quality). Such devices have gained wide popularity among people leading active lives. A significant portion of budget devices do not support even 50% of the above functions.

Global Positioning System GPS(Global Positioning System) was originally planned for use by the US armed forces. It later became the first satellite navigation system used for civilian purposes and is currently used for navigation around the world.

The operating principle of GPS is based on the use of a constellation of 30 satellites, which, in addition to the 27 active ones, also includes 3 spare satellites in case of failure of one of the main ones. The working orbit of the satellites is approximately 19,000 km; each satellite makes two revolutions around the Earth per day. The set of satellites is configured in such a way that it ensures round-the-clock reception of a signal from any point on Earth by at least four satellites, that is, the minimum required to determine the exact location. The GPS receiver calculates its location in relation to visible satellites. The greater the number of available satellites in the area and the stronger the signal level from them, the more accurate the coordinate determination results will be.

The GPS receiver determines the distance to each satellite based on the signal transmission delay. Further, having the spatial coordinates of 3 points and 3 distances to the desired point, the location of the receiver on the plane is easily found. Since the system operates in space and not on a plane, a fourth satellite is required, which makes it possible to unambiguously determine the coordinates of a point in three-dimensional space. Compared to solving a theoretical geometric problem, a practical determination differs in the presence of errors in determining the distance to satellites, which leads to the fact that the result of the determination may not be a point, but an area of ​​a certain radius. However, increasing the number of visible satellites will reduce this radius and, therefore, the accuracy of the location will increase. In practice, a civilian GPS system provides accuracy with a radius of 30 meters, while military receivers provide accuracy up to 3 meters. The number of visible satellites depends on the specific receiver model. In addition, for high-quality operation of the GPS system, mutual precise synchronization of the satellite and the GPS receiver is necessary in order to accurately calculate the delay from a predetermined time of sending a signal from the satellite.

GPS navigation has found the widest application in our time. In particular, in navigators, where it is combined and linked to electronic maps. This technology allows not only to determine the coordinates of the subscriber’s location, but also to plan a route of movement in accordance with the method of movement and other initial requirements. Many mobile phone models are equipped with GPS navigators. The combination of mobile communications with the GPS global positioning system has led to the creation of a new assistive technology - A-GPS(Assisted GPS), which involves using the Internet to improve the quality of the basic positioning system in two directions. Firstly, the GPS receiver, after being turned on, first determines the location of the satellites. Sometimes, due to a weak signal, the procedure can take several minutes. Using A-GPS technology, information about the location of satellites is requested via the Internet in special data centers. Secondly, to calculate the location of a large number of satellites under poor conditions for the passage of signals from satellites, powerful computing power is required, which is not present in all terminals. Sending the obtained preliminary values ​​to data centers and receiving ready-made coordinates can significantly speed up the process of initial positioning. In addition, Internet access can be used for other purposes. This could be, for example, synchronization or obtaining information about the atmospheric state, which can have a significant impact on the calculations.

Recently, many countries have shown interest in creating global positioning systems of their own production. Examples include Glonas in Russia or Galileo in Europe. Such aspirations are caused by the desire to gain independence from the American system, since there remains the possibility of shutting down the system at the initiative of its owner, which could lead to serious disruptions in the functioning of important systems within the state. In such critical civil systems, paired dual systems of 2 or more positioning systems are usually used to increase reliability and accuracy.

Disadvantages of GPS

The following problems may occur when using the GPS global positioning system:

• When the coordinates are first determined, the time depends on the orbital data and the relevance of the history stored in the receiver. In other words, the longer a device has been turned off, the more information it must acquire before a position can be determined. For example, if the device has been unplugged for 2 - 6 hours, it will need approximately 45 seconds. If the device did not work for several days, or when driving more than 300 km without receiving information, up to 12.5 minutes.
• There are severe limitations on the visibility of GPS satellites in urban environments, and in tunnels or enclosed spaces visibility is not possible at all.
• High power consumption of the GPS receiver.

A-GPS functions

A-GPS system algorithms require a communication channel with a remote server that provides information to the receiver. Typically for mobile devices this channel is cellular communication. To exchange information, the device must be located within the coverage area of ​​a mobile operator's base station and have access to the Internet.

There are two modes of A-GPS operation:

• Basic On-line mode, in which the receiver receives information about satellite orbits through the infrastructure and calculates the location based on data received from users. This mode requires a high coverage density from the cellular operator.
• An auxiliary Off-line mode, which speeds up the cold and hot start time of the A-GPS receiver, updating the almanac, ephemeris and list of available satellites. Moreover, the GPS receiver independently receives satellite signals and determines its own location. However, some A-GPS receivers cannot operate in this mode.

Benefits of A-GPS

Among the advantages of A-GPS, it is worth noting the quick location acquisition immediately after switching on and the increased sensitivity of receiving weak signals in problem areas (tunnels, depressions, indoors, on narrow city streets, in dense deciduous forests).

Disadvantages of A-GPS

A-GPS cannot function outside of cellular coverage. There are receivers with an A-GPS module combined with a GSM radio module, which cannot start when the radio module is turned off. To start the A-GPS module itself, a GSM network is not required. A-GPS modules consume a small traffic of 5-7 kB at startup, but if the signal is lost, it is necessary to re-synchronize, which can increase the client’s costs, especially in roaming.

“GPS” in the list of technical characteristics of tablets is already taken for granted. And not a single modern model can do without it. But GPS modules can be of different types, and therefore offer different functions. What are the differences and what is better to choose?

So, A-GPS (assisted global positioning system), a technology that has modernized conventional GPS, improving it in some way. A-GPS allows you to quickly determine the location of the device, while at the same time consuming less battery power. Plus, with A-GPS, the signal can be picked up in hard-to-reach areas - for example, indoors, crowded streets of a metropolis, and even in tunnels. How?

Technologies

How long it will take to determine your location depends on how current the almanac stored in the receiver and the ephemeris are. The almanac is transmitted via a GPS signal and represents aggregate information about the parameters of satellite orbits. The second type of data (ephemeris) is an adjustment of clock parameters, as well as satellite orbits, without which it would be impossible to determine coordinates at all. The ephemeris is transmitted cyclically - every 30 seconds the satellites send data to the receivers.

When operating a regular GPS receiver, the speed of determining the location will depend on how long it was turned off: the longer you were not in touch, the more information the module will have to collect in order not to make mistakes in the calculations. Thus, 6 hours of no activity will make you wait about a minute, and several days “offline” will require up to 12 minutes.

There are “cold”, “warm” and “hot” GPS starts, depending on how current the almanac and ephemeris are.

A regular GPS module receives this data directly from satellites, while A-GPS works through “intermediaries”.

The essence of the changes

In addition to the waiting time, regular GPS also requires considerable energy consumption. That's why, if you're looking at Google Maps, you may not notice how the battery has run out. A-GPS solves both of these problems, but only under one very important condition: if you have access to the Internet. Without communication with a remote server that provides data for the tablet, A-GPS algorithms, alas, will not work.

For tablets with a 3G card and phablets with a SIM card, operator base stations are used, thanks to which the location accuracy can reach 20 m. The more base stations in the area (which is typical for large cities), the more accurate the navigator data will be. It is through them that the module is able to so quickly receive data about the location of your device.

Comparison

Logically, A-GPS is better than a conventional GPS module: the accuracy of determining the tablet’s coordinates, data processing speed and moderate battery consumption should have made this technology ubiquitous. However, A-GPS is a common occurrence among budget tablets (especially those made in China), while flagship models are equipped with regular GPS. What's the catch?

As mentioned above, A-GPS technology requires a connection to an operator network - not all tablets have a SIM card slot, and are not always located in an open Wi-Fi area. Plus, calculating location using A-GPS always involves using traffic. Yes, it is insignificant and some operators provide the data necessary for navigation for free, but there is always the risk of paying for the desire to find out where you are.

Models and prices

If you plan to use more than just Wi-Fi and are willing to pay the bills for 3G, then you can safely go for models with A-GPS. Having a SIM card is a game-changer: you get a device full of benefits. For example, Apple iPad mini 3 Wi-Fi + Cellular: the navigation system works quickly and correctly.

Or another example: in some configurations the same Asus MeMO Pad 7 comes with A-GPS, but there is no slot for a SIM card. The model is one of the most affordable in its power category, but it can only determine your location if you have Wi-Fi. So, let’s say, it’s definitely not suitable for a car as a navigator.

Please note that the lion's share of online stores do not specify which module is in this or that tablet: there is a “tick” next to GPS - and that’s the end of it. If you don’t have to worry about branded tablets, “GPS” in the list of technical characteristics means the GPS module. You need to be careful with “state employees” - you can buy something that is absolutely not what you need.

GSM/GPS modules for car alarms will promptly inform the vehicle owner about its unauthorized use, start, stop or blocking of the power unit, as well as remote performance of service functions. The devices are universal and can be installed on all brands of cars. Some systems are powered from the on-board network, or others from the built-in power supply.

The driver can be informed by sending SMS or voice messages to pre-specified phone numbers of different mobile operators. The alarm is controlled remotely via telephones using the radio channel of the cellular network. Only when commands are issued from specific phone numbers will they be accepted.

Diagnosis of the condition can be carried out thanks to the signal from the LED lamp. Advanced car alarms are designed to operate autonomously. To connect them, it is enough to connect the devices to the on-board electrical network.

Some models GSM/GPS modules for car alarms have energy-saving modes to increase operating life. For example, in standby mode, the integrated battery will consume electricity only if a SIM card is present. And if the main power source is turned off, the system will be able to function for several days.

Thanks to the use of GSM/GPS modules, it is possible to create effective security and telematics systems, which are usually connected via a CAN bus. Unlike conventional car alarms, devices of this type give a signal to the owner, regardless of the distance to him. The main thing is that there is GSM coverage.

Main functions

Most GSM/GPS modules for car alarms perform the following functions:

• Connection via 2CAN bus

• Ability to operate in Slave mode

• Remote control of engine pre-heaters

• Controlling a standard car alarm using your phone

• Immobilizer bypass module control

• Possibility of automatic and remote motor start

• Obtaining data on the coordinates of the vehicle's location

Modern systems make it possible to determine the location of a vehicle with an accuracy of several meters. This is exactly what a GPS receiver is designed for. After sending the request, a text message with the coordinates of the vehicle’s location is sent to the telephone device. Even if the car is stolen, the owner of the car will be able to quickly find it or find out where a member of his family or another driver who is driving the car is now.

Modern modules can process over fifty commands and can also be programmed. You can store several phone numbers in the SIM card memory, and messages will be sent to them. Thanks to the module, you can find out why the alarm went off. Was this caused by an open door, starting the engine, triggering the shock sensor, disabling the parking brake, etc.

Branded GSM/GPS modules will greatly increase vehicle protection and ease of use. Thanks to them, vehicle owners will always know where their four-wheeled friend is and what condition its main systems are in.