GPS using AVR is possible to develop
at home with an AVR microcontroller and a personal computer. GPS
(Global Positioning Software) is widely used across the world as a
means to aid navigation. The basis of a GPS system is a network of
satellites which are orbiting the planet, relaying information back to
the surface of the planet, and picked up by receivers which are able to
read the latitude and longitude of their global position. Not only can
a GPS system track location, but it can also detect time as well as the
velocity of travel. Such a device can be connected with an AVR
microcontroller
By hooking up a GPS system to an AVR you will be able to recreate a map
on the chip, providing full data of the GPS system. There are designs
for such tasks on the internet, and the overall process may not be as
challenging as one would imagine. In general, the code need to power
GPS using AVR is relatively short, with most of the code taking up the
bitmapping of the graphics for the map. The most commonly used method
of transmitting data is called NMEA which is based on strings of ASCII
36, and the whole meaning of the string (which always begins with a
'$') will be
described by the very first word.
A GPS string which begins with $GPGLL will provide data for latitude
and longitude, as well as time and date. A full string will have the
numerical values of the two important factors of latitude and
longitude, along with a checksum to make sure that data is being
received on a regular basis. A multitude of these MNEA strings can be
sent every second to the AVR microcontroller, and if the GPS fails to
pinpoint either a latitude or longitude, it will just keep turning out
the same strings until it can fix on a proper location point.
Global Positioning System reaches right across the world, and GPS using
AVR only utilized two simple connections between to the two main
modules. All of the power of the programming within the
microcontroller, which is done via the user's own code, will display
the map and do all of the calculations of latitude and longitude. With
this code at your disposal, you can watch it in operation and debug it
if necessary or even tweak it to be more efficient and hone it to your
own needs and preferences. GPR with AVR is just another great example
of the functionality of the Atmel AVR technology in microcontrollers.
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