Display current location of the vehical

Hi All

I need to display current town name on a LCD near the passenger seat of the bus

This is the things I supposed to use

Microcontroller
LCD
GPS sensor

Please advice the procedure and basic concept any other solution other than above parts

Thanks in advanced

Assuming you have the software to drive the LCD already:

1. read the GPS
2. check which boundary the latitude and longitude fall within
3. display the name of the bounded area on the LCD.

You will need some kind of a database, pre-loaded with the boundary information, the GPS signal will not tell you the name of the location, only its coordinates. As the boundary need not be very accurate, you might be able to use simple rectangular regions then a comparison of east/west then north/south (or the other way around) values to generate a look-up value into a table of town names.


Brian.

betwixt said:

Assuming you have the software to drive the LCD already:


Brian.

Click to expand...

Thanks for the reply

Yes...I can find the codes

Can I able to find coordinates using google without visiting the exact location with GPS sensor?
Can I use google map to find location very accurately than the GPS?

I checked with google map but it is wrong what i am reading with GPS sensor

Thanks in advanced

I find Google Earth to be very accurate, moving the cursor displays the coordinates at the bottom of the screen and they match closely with my GPS device. I'm not sure how accurate other Google maps are. For town boundaries you don't need exact coordinates and if you assume rectangle outlines they won't match the town development area accurately anyway.

I know there is a clever algorithm that reports whether coordinates are inside or outside an irregular shaped boundary, I use a system that tells me which Police station covers different addresses by clicking on a map but I do not have access to the source code. I suspect it is far too complicated to run on a microcontroller.

The problem is making the application database small enough without losing too much accuracy. You will probably find an array of latitude and longitude values to discover a town code is most efficient. For example 'TownCode = Database[Lat][Long];' then a second table to look up the town name against the TownCode number. If you subtract the latitude and longitude of the lowest numbered corner of your region it will make the table indexes as small as possible.

Brian.

Hi,

You say bus ... does this mean there are predefined routes (in opposite to random driving across the land)?

If so, it's far more easy.
Just make a list of the town's names and their coordinates.
Then compare the actual bus coordinate with the town coordinates and find the nearest town... display it's name.

If your list of towns is in the correct order of the bus route, then finding the next town is even easier.

****
You may add additional informations to the display, like distance to the next town, expected arrival at the next town, street(location) of bus stop, bus stops automatically or only on request...and so on.

Klaus

I checked with google map but it is wrong what i am reading with GPS sensor ...

Click to expand...

That is very strange; when I put the gps coordinates into the maps.google.com, I get my location accurately (within +/- 5 meters; rough guess).

Without gps, google can locate you using the towers and the signal strengths (that is not so accurate). Google uses tower location databases which may have some mistakes.

PA3040 said:

I checked with google map but it is wrong what i am reading with GPS sensor

Click to expand...

No one has ever found google maps to be wrong. Perhaps if you gave an example of your readings we could point out any mistakes?

Please note that typically GPS devices show coordinates as xx° yy' zz" while Google shows it as xx. abcdef° . These are not identical and have to be converted to cross-check

c_mitra said:

That is very strange; when I put the gps coordinates into the maps.google.com, I get my location accurately (within +/- 5 meters; rough guess).

Without gps, google can locate you using the towers and the signal strengths (that is not so accurate). Google uses tower location databases which may have some mistakes.

Click to expand...

How should i get the google map coordinates to micro controller, Without using GPS

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KlausST said:

Hi,

You say bus ... does this mean there are predefined routes (in opposite to random driving across the land)?


Klaus

Click to expand...

Yes..It is predefined routes

Still I am not clear how should i read rectangular ordinates to show town because I need to show town name certain distance

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betwixt said:

For example 'TownCode = Database[Lat][Long];' then a second table to look up the town name against the TownCode number. If you subtract the latitude and longitude of the lowest numbered corner of your region it will make the table indexes as small as possible.

Brian.

Click to expand...

Say just pass the town code but still in the town