GPS Return to home circuits?

[AXI Motor Models]

Hi,
Does anyone know of any rudder control, return to home circuits which I can build (with source code)?

Can the RCAP circuit perform return to home function with an OEM GPS module? Resources for the RCAP project seems to have diminished.


Thanks

[kd7ost]

MX took over the RCAP project but I think it died down due to lack of appreciable business. You may want to try to contact him.

http://www.rcgroups.com/forums/member.php?u=5106

Two other devices that are obsolete but can be found from time to time is the AP4 and the PDC-10. I've used the PDC-10 and RCAP and they both worked well. Never have seen the AP4.

You might want to post a thread asking if anyone has one of these gadgets for sale. I know the code for the PDC-10 won't be released and have no clue about the AP4 code. MX might be your best bet with the RCAP.

Dan

[ios]

RCAP3 is still available from the following site, but I don't believe the source code is available;

http://alai.h3m.com/~s0350672/catalogo/index.php?cPath=43_51&osCsid=7994ca1fe300748a9b69a85e3d11d7cd

If you want to use RCAP3, you'll also need to get the WPS and EM-406 GPS module, as well as associated cables - (RCAP3+WPS+GPS), all available from the above site. This will allow you to do both return to home, as well as waypoint based navigation if you buy the RS232 to TTL adapter for the WPS.

If you also want to have control over altitude, you will also need the ALTHOLD+ZLOG units - which will give you throttle based altitde control.

And finally, if you intend to use this setup on a non-dihedral based plane (non-glider), the FMA CPD4 does the rest.

The above is a great setup if you have the money to spend and time to experiment, but if you can wait for Attopilot - for around the same price you can get a heaps more functionallity and user friendly operation and setup.

If however you want to get dirty with code, I would sugget having a look at the following;

http://rcpilot.sourceforge.net/
(this is an early version of RCAP)

or Paparazzi which has alot of users and support on this forum;

http://paparazzi.enac.fr/wiki/index.php/Main_Page

Finally,... there is a fantastic article in the July/August 2007 Issue of Elector-electronics which describes a circuit and code for single PCB GPS guidance system for autonomous vehicles, which can easily replace the RCAP3+WPS+GPS,... but also includes source code which can be further developed to your needs.

Hope this helps,... best of luck

[2jers]

Hi ios
The articles name is : " SatNav for Robots" ???
Thank you
Nikos

[ios]

Hi ios
The articles name is : " SatNav for Robots" ???
Thank you
Nikos

Yes, thats the one - page 78 :)

Great to see another greek who is interested in UAVs.

Take Care

Nikos :)

[2jers]

:) :) :) :) :) :) :) :)

Goodmorning Nikos, how small the world is.........

I pm you
Thank you
Nikos

[AXI Motor Models]

Thanks for the information
The Elektor-electronics magazine looks good.

The best solution for me would be the RCAP version 1.1 (as that's the only version I can find the files for so I can build it myself) with a garmin GPS. In the future I could eventually create a board to replace the garmin with an OEM GPS module (similar to the WPS board).
Does anyone know of any problems with the early 1.1 version of the RCAP?
Thanks

[kd7ost]

Yes there was a problem but I don't recall the exact details. It is fixable for sure. I would peruse this thread and see if the answer is there.

http://www.rcgroups.com/forums/showthread.php?t=484568&highlight=RCAP

What I recall is that the 1.1 code worked with a Garmin12 GPS unit. It was, uh vintage gear. But a fix was made in later code that resolved that.


The newer handheld GPS units put out the NMEA strings at a faster rate. The 1.1 code didn't allow for that and wouldn't work unless you used the GPS12 behemoth. Not a good option. Plus the GPS12 shut down easily in flight and if you turned it back on, it wouldn't recall it was navigating. Newer smaller units like the geko 201 could be turned off, turned back on and they would resume last course till made. They also didn't have the propensity of shutting down in flight but I always powered mine from an external source as well.

Dan

[kd7ost]

Maybe it was the opposite.

Maybe the early version had fewer strings at put them out at .5 second rate. And the newer ones were only at a 1 second rate.

Anyway, it was fixed in a later version.

Dan

[AXI Motor Models]

The ArduPilot also looks very good at only $30 http://diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A44814

[Blue Sky]

Allot of information can be found here. http://www.diydrones.com/
You probably have seen Range Video's OSD with return to home.
http://www.rangevideo.com/index.php?main_page=product_info&cPath=49&products_id=135&zenid=2313566819607541d9a0593d7ddd07a6
-Dave

I see you beat me to the post!

[AXI Motor Models]

I've seen the rv osd but I would prefer to build my own circuit from resources online to lower cost and so that I can customise the features of the circuit. Diydrones is growing fast!

ios, do you know if the circuit in the Elektor-electronics magazine directly controls a servo for navigation?

[ios]

ios, do you know if the circuit in the Elektor-electronics magazine directly controls a servo for navigation?

Yes it does. I have the magazine at home. I'll bring it into work tomorrow to scan & PDF the article and upload it here for all to see.

[Gary Mortimer]

Brill, thanks I was hoping someone was going to do that.

G

[AXI Motor Models]

I just came up with another question - does anyone know whether the RCAP will work South of the equator?
Thanks

[kd7ost]

I just came up with another question - does anyone know whether the RCAP will work South of the equator?
Thanks


Yes,

Because RCAP operates using the NMEA output of the GPS unit itself. The manufacturers of those units (Garmin, Trimble, Etc) have all that worked out for worldwide markets.

The problems have come from manufacturers of their own code and GPS engines by not taking the variations in numbers into account. -/+ longitude and etc.

The RCAP is very simple. It only translates directional error signals from the GPS into a proportional servo command. So it will work with any GPS that works in your area, and has a standard RS232 output option.

Dan

[ios]

Yes it does. I have the magazine at home. I'll bring it into work tomorrow to scan & PDF the article and upload it here for all to see.

Sorry guys, I forgot the article yesterday, but here it is. I think it would be great if someone was to develop this further as a single PCB replacment of the current RCAP+WPS. If anyone does, please keep us informed of the progress - it would be nice to have a true open source - simple - autopilot which could serve to educate new guys on development of hardware and software in their early learning stages.

So on that note; enjoy. :)

[Mark Hanson]

The PICOPILOT-RTL (return to launch) is a complete "off-the-shelf" unit for $350 that includes a rudder controller, wing-leveler and GPS all in one small package.

http://www.u-nav.com/picopilot/pprtl.html

[zlite]

The PICOPILOT-RTL (return to launch) is a complete "off-the-shelf" unit for $350 that includes a rudder controller, wing-leveler and GPS all in one small package.

Again, disclosures are in order. Mark, it's only fair that you mention that you work for UNAV when promoting its products.

[Gary Mortimer]

I will second that, I think its forum abuse myself!

Ios thanks very much for posting the articles I'm sure many people will find that useful.

[AXI Motor Models]

I found another GPS navigation article here that someone might be interested in: http://www.pages.drexel.edu/~weg22/gpsMagpie/gpsFixedWing.html

I have been working on a combined RCAP + WPS but have had a problem. I can see the servo position update at 1Hz but it intermittently stops updating the servo position and the servo just freezes. (and then it resumes updating)

Here is a video: http://www.rcgroups.com/forums/showthread.php?t=979225