[hamilc]

I have read that the Revo does not have a compass.  However I think that the Revo has a magnetometer. So what is the compass issue? Can I program the Revo to fly a designated path?

[TheOtherCliff]

Yes it does have a compass.  The problem is that it the Revo is usually mounted too close the high current (thick) power wires and the data gets distorted by the electromagnet effect.

You can program Revo to fly "waypoint" it is called.  Get it flying without GPS first and read some threads here about setting up GPS/mag.

[hamilc]

So, what would you recommend as a good GPS unit to use? I think I saw a reference to a DJI NAZA GPS/Mag. Is this a good one or is there a better one?

[TheOtherCliff]

I think that the DJI is the best GPS option of the ones you can still buy.  They are about $38 for authentic ones on eBay and about $28 for clones.  You will have to make a cable for it.

The authentic DJI has a lot of filtering in it.  The filtering reduces GPS wandering, but slows down the data to the point that it oscillates in LP GPS modes.  DJI FC's take it into account and don't oscillate, but they also take about 10 seconds to return to the correct place if something moves them away from it.  I have some code posted in another thread that fixes the issue for me, but needs more testing.  One other guy flew it and said he thought it was better too.

I bought a DJI clone too, and the one I bought locks up maybe every 24 hours of use.  I don't think anyone else has reported issues, but they haven't run continuous tests for days like I have either.  I know it is not our code that does this because we never ever send it anything.  It is used as a read only device.

[hamilc]

I have ordered the DJI NAZA so I hope it will be OK.