Latitude & Longitude Display System Using GPS & AVR Microcontroller

This project is a reference to budding engineers or a helping hand to those who willing to work and interface a GPS Receiver with microcontroller and making their own channel to communicate with satellite, seeking for some useful information from satellite to make a effective and efficient system.

Before we check all the details of this project, here is the final implemented circuit diagram of longitude and latitude display system using GPS and AVR microcontroller.

GPS

In a simplest way ‘The Global Positioning System (GPS)’ is a satellite-based navigation system that consists of 24 orbiting satellites. This satellite transmits an amount of information in string format (e.g.: latitude, longitude, altitude, time etc.) which we are going to cover further.

GPS Receiver

GPS Receiver received the information in string format, transmitted by Satellites, which uses this information to calculate different parameters between it and satellites. With information from satellites, a GPS receiver can fix its location on the ground from the known position of the satellites.

Now I want to drag your attention on the purpose of this project. In this project, we are going to display ‘Latitude & Longitude’ used for positioning of an object on the earth. So let’s talk about how a GPS receiver fixes its location on the ground, as i above said and the find the location of an object on the earth.

INFORMATION TRANSMITTED BY SATELLITES

A list of information as string format given by Satellites as shown below in Table-1:

Along with this information, we need to find position which the ultimate purpose of our project, so we are going use only ‘GGA’ string. All string starts with ‘$GP’ which is a "talker ID" a two-character prefix that identifies the type of the transmitting unit. By far the most common talker ID is "GP", identifying a generic GPS. The detailed description of ‘$GPGGA’ string is given below in Table-2 and Table-3: