Interfacing GPS with 8051 and displaying the output data in NMEA format from the gps module to 8051 microcontroller and finally displaying the latitude and longitude information also the date and time in a LCD display.
2. Objective of this project
• The Latitude and longitude values are extracted from the data in
NMEA format the GPS module and display it in the LCD display.
• To extract time information and convert it to IST format and display it
in the LCD.
• To extract date information and display it in the LCD.
3. Components used
• GPS module (GY-NEO6MV2)
• 8051 microcontroller
• 16*2 LCD display
• Few switches
4. How Does GPS Work
• GPS receivers use a constellation of satellites and ground stations to
compute position and time almost anywhere on earth.
• The primary purpose of the 12 visible satellites is
to transmit information back to earth over radio frequency (ranging
from 1.1 to 1.5 GHz). With this information and some math, a ground
based receiver or GPS module can calculate its position and time.
5. Working
• . If the GPS receiver’s antenna can see at least 4 satellites, it can
accurately calculate its position and time. This is also called a lock or
a fix.
• To configure a GPS receiver, knowing the type of chipset your GPS is
using is very important. The GPS chipset contains a powerful
processor that is responsible for the user interface, all of the
calculations, as well as analog circuitry for the antenna.
• The chipset also allows for data to be sent to the GPS receiver to
configure parameters like, update rate, baud rate, sentence selection,
etc.
6. Message Formats
• GPS data is displayed in different message formats over a serial
interface.
• Nearly all GPS receivers output NMEA data. The NMEA standard is
formatted in lines of data called sentences.
• Each sentence contains various bits of data organized in comma
delimited format (i.e. data separated by commas).
$GPRMC,062521.004,A,5404.2675,N,00159.7569,W,000.0,000.0,061017,,,A*78
$GPGGA,062521.004,5404.2675,N,00159.7569,W,1,10,4.00,100.0,M,50.0,M,,*7A
$GPGSA,A,3,13,11,20,28,14,18,16,21,22,19,,,4.00,3.20,2.40*0B
7. Extraction of Latitude and Longitude values
from NMEA Format
• The first received 6 characters from GPS module are compared with string
$GPRMC, if matched then will go for further process otherwise repeat the
same process again.
• If string is matched then wait till you will get two 2 commas, next character
indicates weather the GPS is activated or not.
• If this character is A then GPS is activated otherwise GPS is not activated.
Now again wait till you get comma (,).
• The next 9 characters indicate the LATITUDE. Wait till you get 2 more
commas (,) the next 10 characters indicates the LONGITUDE.
• This data is sent out on the serial port at an interval called the update rate.
8. Message Formats
Obtaining data from the string $GPRMC
Time: 144818.317 is 14.48 and 18.317 seconds in Greenwich mean time
Latitude: 5404.2675,N is latitude in degrees.decimal minutes, north
Longitude: 0159.7569,W is longitude in degrees.decimal minutes, west
Date:051017 is 05.10.17
Number of satellites seen: 10
Altitude: 100 meters
14. Circuit Applications:
• Used in tracking devices and mapping devices
• Used in personal positioning
• Date and time monitoring
• This project is used in embedded system applications to find
out the location.
• VR games.