GPS tracking and Overlay
BrettK
Posts: 7
Hi to everyone.
As an Automotive Engineer I am fishing for you help... I have the job of displaying (as an arrow vector) the GPS "movement" of a fast moving vehicle on a display. I intend on using the Parallax GPS Reciever Module to aquire the data.
Which microcontroller would be best if I intend to perform some basic integration and manipulation of the data streaming in from the GPS and then display in real time the moving arrow (representing vehicles' vector) on a 7in LCD display as an example? Also would it be possible to transmit via RF the result of the data maniulations from the same package? I need to make this an all in one standalone package (user input is NOT necessary).
I will greatly appreciate any help, hints and crit.
Regards
Brett
As an Automotive Engineer I am fishing for you help... I have the job of displaying (as an arrow vector) the GPS "movement" of a fast moving vehicle on a display. I intend on using the Parallax GPS Reciever Module to aquire the data.
Which microcontroller would be best if I intend to perform some basic integration and manipulation of the data streaming in from the GPS and then display in real time the moving arrow (representing vehicles' vector) on a 7in LCD display as an example? Also would it be possible to transmit via RF the result of the data maniulations from the same package? I need to make this an all in one standalone package (user input is NOT necessary).
I will greatly appreciate any help, hints and crit.
Regards
Brett
Comments
-Phil
The vector arrow will for now just be layered over a map of a fixed area, so basically just an image.
The display will be hard wired to the processor, the rf output is just to communicate the systems health and status to another system.
Thanks
Brett
-Phil
The image aswell as the display format will be chosen according to your suggestions, no cameras are involved so whatever is easiest for a microprocessor.
As for using the embeded computer, would I still be able to wrap it all up in a hand holdable package?
Sorry for the delay in replies, South Africa is a few time zones away.
Thanks again
Brett Kent
Due to the limited RAM available in the Propeller chip (32K bytes, shared with program space), your output resolution will be very limited if the image originates from within. You can increase the pixel resolution by limiting color depth. For example, a 160 x 120-pixel image with 8 bits of color depth would require 19200 bytes, the same as a 320 x 240 image with two bits of color depth. What are the color and resolution requirements of your map image?
-Phil
The image works well at 2bits of colour, I have just droped the resolution to 320x240 and still looks great.
Could I expand the RAM if need be?
Brett
-Phil
The image is an outline of a Game Park, the device I am trying to build will be used to assist the rangers in anti-rhinoceros-poaching, Releasing the image could work against the effort. Please accept my apologies.
This is a device intended for the african bushveld, hence the need for a small rugged package and my haste too.
Have you seen this site?
Although I'm sure the Propeller with a VGA output could handle your task, I wonder if it might b quicker and easier just to buy an automotive GPS unit and install a map for your area.
-Phil
As for the radio requirement, what are your specifications? Distance, speed, etc. I suspect that you'll have to use either satellite or a ham band to cover the distances involved.
At the top you mention "fast moving vehicle." Without knowing how fast you need to update your data, remember that GPS receivers don't generally guarantee updates faster than 1 per second for each type of sentence. You don't mention the actual GPS module you're using, but I'd advise against any with a "smart mode," as those take longer to acquire all the various bits of information (each query re-parses the next data sample). You can speed things up by doing the parsing yourself, and on more than one sentence type. If the receiver supports it, you can disable sentence types you aren't going to use.
-- Gordon
I recently tried to make a GPS pedometer to keep track of how far my wife and I walk in the evening.
I used this GPS module and logged our positions to a SD card using a Propeller.
When I attempted to add a LCD to display a simple map, I found the circuitry to control the LCD (I think it was the voltage booster for the backlight) caused the GPS module to lose its lock on the satellites.
I've also had trouble using the GPS module with a switching power supply.
I've been told there are ways to shield the interfering devices but I wanted to warn you about this possible complication.
Duane
Commercial products are good and worth their cost. But the device I am trying to develop needs to be magnitudes cheaper, simple to use (for illiterate users) and very specific in function. Allow me to explain; A device will be carried by every ranger both in vehicles (quads and off-road vehicles) and on foot. They all know the terrain like the back of their hand, so a detailed map is a luxury. The RF comms is to link together all the devices, possibly as a chain type network. Hence on a particular device the user can see his position in relation to his/her collegues (4Hz would be perfect, 1Hz might be a bit slow for the vehicles). Distances could be as far as 10 miles, so an external transciever will probably be used. The idea is to fit a similar (display-less) system to a rhino (and other game perhaps) to make their position known to the rangers too.
It has to be cheap, simple and rugged. Thats why I have to do this myself, current commercial products are failing badly at the basic criteria, and sofar this year more than 300 rhino have been poached. The South African Air Force and ground forces are working hard to controll the problem but more is needed from the public sector.
Brett
You might be able to find a wireless tranciever and create (or buy) your own antenna that would increase the range. I'd start with some of the modules from sparkfun, but with new (bigger) antennas: http://www.sparkfun.com/products/560 You might also want to take a look at the 900MHz XBee module: http://www.sparkfun.com/products/9087
The Digi xtend modules have the range and speed requirements that you want, but they are expensive (~$250 each).
As for the communication speed, you can have each module report it's position and velocity, and then on each module calculate the estimated position for all the other units.
I'd think using a Propeller as a modem that plugs into a walkie talkie would be the way to go. You could use the walkie talkies for voice communication and also have data transmit over the same frequency (I haven't done this).
If you think the 900 MHz XBee are promising, I'm willing to run what ever tests you think would be helpful with mine.
Duane
The data will be encrypted slightly, remember most poacher are barely capable of reading never mind decrypting. The king pins on the other hand might make a go of it but regardless the rhinos will be under permanent serveillance if these devices can be made. I would rather use the walkie talkie hardware and integrate it into the device. Much easier to run with one device strapped to you
Regards
Brett
A month ago I purchased six of these GPS loggers from Sellout Woot.
At $20 dollars each, it would be hard to beat the price. If you could get a bunch at a low price, they might be worth modifing to do the things you want.
They aren't hard to take apart but I have no idea how to control the screen with a Propeller. If I can tap into the GPS output I think they will be worth the $20 I paid for them.
Duane