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Designing gps photography plane

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I am new to the UAV/RPV world, but am interested in building a small plane with an onboard digital camera and a gps for navigating the plane to a programmed coordinate location to take a picture. I imagine its been done before, but I would like to build the smallest and simplest design for it. I want to use an inexpensive gps unit like a Garmin Geko and interface to a microcontroller (like a PIC) that drives the servos. Do you guys have any advice or know any good websites that could assist me in developing it?

Thanks,

John

Edited by laserbounce

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Do you have experience programming PICs? If so what languages have you used.

How comfortable are you in designing PCBs?

I ask to know what level of a project you would be comfortable with.

Edited by mikep

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Mike,

I have experience writing custom programs for PIC microcontrollers in C and assembly and etched a few custom PCB's. I tried searching the net for info about gps interface communication protocols and found a few sites, but I have not yet figured out how to implement it for plane navigation.

John

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I basically have what you are looking for written in PicBasicPro.

I have finished the code for the navigation and most of it for the altitude hold.

Just the fluff left for altitude.

The PCB for the navigation is complete and the altitude module still needs to a bit of work however I have put it on the breadboard and it just needs to be translated to a PCB.

If you are interested in completing it, and sharing it let me know.

You can see basically what I did at:

http://groups.yahoo.com/group/rcpilot/

Take a look in the Files section.

I woukld like to simply put the code up somewhere on a public CVS server as well as the design docs etc.

Cheers,

Mike

Edited by mikep

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Hi John,

If you main goal is to 'roll your own' then it sounds like you are well on your way with Mike's assistance.

If the end result is your goal, then you should look at the pdc10 available here:

http://www.u-nav.com/pdc10.html

This unit, coupled with the FMA copilot available here:

https://www.fmadirect.com/site/fma.htm?body=Store

This setup can fly an airplane between a series of waypoints. Cyberflyer (member on the board here) has done it, and I've copied his idea to use on an electric airplane:

http://www.yb2normal.com/uavtwinstar1.html

The only piece left really is triggering your camera!

Regards,

Bill

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Okay, I checked out the Yahoo rcpilot group and it seems like a great design. I'm looking at gps' that are lighter weight, but I have heard that the communication protocol of the Geko's are slightly different than other Garmin units, do you know what compatibility issues different models might have and if they are best suited to UAV usage? Mike, do you have a website where I could view some source code? I I would like to contribute to the project if I may.

Thanks,

John

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That would be great.

I will e-mail you the source code later on today and setup a CVS server later this week.

As for the gecko. The only thing I noticed between it and others (non-garmin) were the senteces do not come down in the same order. I had to make some mods in the code because of that. But besides that all seemed the same.

If you take the case off of the Gecko, it is quite light.

The main advantage of these compared to GPS oem units is that you have the waypoints. This could be programmed on a pic as well, but alot of extra work.

Cheers,

Mike

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Hi Guys,

I live outside the US and can't order from Unav due to their export limitations. I'm therefore looking to roll my own PDC10 to read off my Geko 201 and steer with the rudder while correcting roll with an FMA copilot, a la what Cyberflyer and yb2normal have done. Got all the parts except the PDC10 lookalike. I have programming experience in six languages from past college courses but no PIC experience yet, though I don't think that's a major hurdle, and have recently acquired a simple PIC programmer from Talking Electronics.

Now comes what for me is the "smoke and mirrors" part of the process. How would I go about writing the code for the PIC? What does the Geko output (commands, bytes, bits, what-have-you) and where do I get a list of this output to work with? Then, how do I translate the list into an output that's useable by the rudder servo?

(I hope I can do this without having to get a PhD in imbedded microcode first.)

Thanks,

Bruce

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