The GSM modem is intended to provide a connection between the tracker and the GSM mobile network. The GSM signal is received and transmitted via an internal GSM antenna. The tracker is equipped with two SIM card to be identified by the GSM network and to be able to access the services provided by the mobile network operator.
The GSM modem performs several functions:
- Enables the device to access the GSM network and to be identified by the network using the SIM card.
- Enables data exchange (including transfer of track points) between the AutoGRAPH-Mobile tracker and the server via TCP/IP through the Internet by means of General Packet Radio Service (GPRS).
- Enables exchange of information and control SMS messages and USSD requests (for example, for subscriber’s personal account monitoring).
GLONASS • GPS RECEIVER
The GLONASS/GPS module is designed using a highly sensitive receiver based on high performance uBlox M8 engine. It receives coded signals by means of internal GLONASS/GPS antenna from the satellites of the Global Positioning System (NAVSTAR) and GLONASS, and uses its internal computer to determine the geographical coordinates of the receiver position, the exact time, speed and direction of movement. Received data is transferred via NMEA protocol from the GNSS module output to the central processing unit for further processing.
The uBlox MAX-M8 supports concurrent reception of two GNSS systems and, as a result, the information being received is highly accurate and available even in the case of very poor visibility of satellites.
CPU (CENTRAL PROCCESSING UNIT)
The central processing unit is the core of the AutoGRAPH-Mobile controller, which unites all of the system components together and ensures their interaction in accordance with the program stored in the device.
The processing unit is a highspeed single-chip microcomputer able to perform computations of at a speed and accuracy level that is sufficient to meet various navigation and service challenges.
The custom firmware, developed by TechnoKom specialists, enables the CPU to receive data from the different modules of the system, to perform logical and mathematical processing of the data and to control the modules as appropriate. It should be noted that the functional capability of the controller firmware is being constantly enhanced and extended so as to provide users with new and improved features and options.
POWER SUPPLY DRIVER
The operation of the tracker can be provided with the rechargeable Li-Ion battery, supplied with the tracker, or with the external power supply voltage of the 5 V.
The power supply driver with protection circuits generates all of the necessary supply voltages for tracker components. Furthermore, the power supply driver protects the tracker against polarity reversal, voltage overload, interference, etc.
Rechargeable battery provides autonomous operation of the tracker till up to 72 hours. To prevent Li-Ion battery over-discharging, the power supply driver provides the tracker turning off if the battery charge is low.
The AutoGRAPH-Mobile has a built-in charger to charge Li-Ion battery, supplied with the tracker. When the tracker is powered by the external power, the power supply driver turns on the charger. To protect the battery from the overheating when charging and to prevent the battery overcharging the power supply driver provides the charger turning off if it is necessary.
The Non-Volatile FLASH memory module serves as a black box storage device to store the collected data.
The FLASH memory module is designed to store up to 270,000 records for up to 10 years – even when the device is powered off.
The FLASH memory module in the AutoGRAPH-Mobile is designed to use the ring buffer principle, which means that new records will be written over the oldest records first, ensuring that the most recent data is always available.
The AutoGRAPH-Mobile is equipped with 3-axis digital accelerometer with wide range of full scales from ±2g to ±16g intended to detect motion, determine the tracker’s orientation, measure vibration level, etc. The accelerometer is used to detect the tracker idling and thereafter switch to the sleep mode to provide battery power saving.
The USB port embedded into controller is intended to:
- configure and check the performance of the controller by means of the configuration program – GSMConf;
- read data from the device so as to deliver them to the AutoGRAPH Dispatch Software;
- update processor microcode (firmware) of the device;
- use the controller in the «GPS mouse» mode.
When using the device as a GPS mouse, the tracker, which is connected to the USB port of a PC, laptop or PDA with a data cable via virtual serial port (СОМ port), transmits the location data in RMC format through the NMEA protocol once per second. This enables the users to locate the object equipped with the AutoGRAPH-Mobile using software such as OziExplorer, Google Earth Plus/Pro, 2GIS for PC 3.0, Garmin, Navitel and many others. For details please refer to «Using the GPS mouse» document.