Location Based Advertising For Public Transport

Thread Starter


Joined Aug 7, 2011
Hello everyone, I'm thinking of doing a project on Location Based Advertising(For Public Transport) but I'm a complete beginner at practical/projects. I have the basic idea of what i need to do but i really don't know how to do it.

I'm doing this for a minor project so I'm currently making only a smaller component of a bigger project so i can later add more functionality and use it as my major project.

-What do i need for a GPS - module or receiver : is there a difference?
-What is it's output - {Latitude, Longitude}?
-Can i keep a table in the programming that maps the {lat, long} -> {location name}
-If not, how do i do it?
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Joined Apr 30, 2011
Research NMEA sentence structure. That's the output you'll get from the GPSR. I don't think you neccessarily need to decode to a location name but merely define a range of valid coordinates for each ad and compare them to the current location on the GPSR. It may help to set up a user grid for the city or area of interest in UTM format since that would be a linear cartesian coordinate system that's easier to use for comparison to defined ranges.
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Joined Sep 9, 2010
-What do i need for a GPS - module or receiver : is there a difference?
I use a small bluetooth" puck receiver with the SirfStar III chipset, which I gather is a quite popular set. My device is a BT-359 from US Globalsat. I believe you can get these now for well under $50.

Mine plays nice with Mac, PC and Blackberry. It gives a fast lock and seems to be quite precise.

If you don't mind using a tether (USB cable), I think you can get even cheaper receivers since they don't need their own battery.

For your project as described, you do NOT need a gps handheld with its own display, onboard maps and so on. Those features add cost, and you don't need it.

The feature you are describing is called geofencing, and some of the gps tracking apps have a a feature of sounding an alarm if the receiver crosses the established fence. What you want is a display command instead of an alarm.


Joined May 25, 2011
Geofencing seems to be emerging with some emergency services, maybe a call to your local mass transit or emergency services might gleen some ideas.


Joined Feb 19, 2009
For your application, you'd want to use GPS coordinates for location based ads.

What I'm guessing the project is would be 3 billboards, and a bus or train, so as it moves, the billboards do not display the same ad twice.

Bluetooth wouldn't fit the bill for this, that would be more like what is shown in the movie "Minority Report", where he walks into a store and the ads greet him by name, etc.

GPS would give location, the 8051 would signal the sign to display the new ad/alert/etc. If the matrix is on the moving vehicle, this is pretty straightforward. If the matrix is a stationary billbaoard next to the bus/train route, then you will also need an ability to signal the billboard to change to the correct ad (bluetooth not optimal for this, but some RF solution would be).

If you only have one 8051 and not much else for hardware, I'm guessing the matrix would be on the moving vehicle, perhaps a tour bus that alerts passengers to points of interest as they move along?

-ETA: Look up using the UART on the 8051, the NMEA format gives latitude and longitude, as well as how precise the signal is and a lot of other data. You only need to read in the data from the GPS receiver (pick a brand above), get the coordinates and precision. If precision is acceptable, use coordinates to display message on dot matrix through output pins.