Home Point Theoretical question

Prylar Bek · Nov 15, 2014

So, after I do a compass calibration and get ready to fly after receiving the blinking green lights, when does the 'home point' get set? I ask because on my initial flight I did the 'compass dance' at the work table outdoors about 50 feet from where I set her down and launched. And after thinking about what would happen if I had to trigger RTH, (Failsafe) would she come back to the table where I did the compass calibration or to the spot where I had lifted off from???

RDCF550 · Nov 15, 2014

That information is in the manual, that not many people seem to even be browsing. :?:

The fast blinking Green = Home point recorded, so it's coming back to the spot where that happens. You should also calibrate your compass from where you're taking off, not calibrate it and then move to some other location.

N017RW · Nov 15, 2014

Not to be too nit-picky...(for a P2 [non-vision] in Naza Mode)

The first set of rapid green flashes indicates the heading or forward facing direction has been recorded/stored/etc. (for Course lock).

The second set of rapidly green flashing lights indicates GPS has acquired 6 or more satellites.

Sometimes the two sets of rapid flashing green can happen somewhat simultaneously and you get a single extended period of rapid green flashes.
(In this case I usually start over to be sure)

Now once you start the motors (and you should ALWAYS wait for two sets of green flasing sequences before doing so) the Home Lock position is saved/recorded/etc.

Never had a fly-away or any unexpected operation in 75+ flights following this method.

Compass calibration frequency and requirement is a debate-able topic.

I do not calibrate unless I have added, moved, or removed hardware on or within my P2.

TEHO - YMMV

Prylar Bek · Nov 15, 2014

Sorry should have posted in PTV+ anyway I have READ it several times just trying to get practical answers. So next time I'll do thecalibration dance and get the home lock from exactly my launch point. Makes sense thanks

Prylar Bek · Nov 15, 2014

Sorry reread your post. What do you mean by two sets of green? How do you trll

N017RW · Nov 15, 2014

promocop said:
Sorry reread your post. What do you mean by two sets of green? How do you trll

Again a P2nv in Naza mode...

For me in S. Fla. I get the first set of rapid greens at about 30 sec. after power up (course lock heading).

The second set is another 15-25 secs after that (GPS 6+ sats.).

If I fly back to back batts. I beileve the GPS board's back-up super cap(acitor) aids the GPS to allow a 'warm' start (faster acquisition) and it can get 6+ sats. sooner resulting in a prolonged green flash indicating both heading and GPS are essentiall 'ready'.

This is unnerving as I want to see two distinct sets of rapid greens.

RDCF550 · Nov 15, 2014

@ promocop - No offense intended. Rapid Green flashes = Ready to Fly in Phantom 2 Mode or NAZA-M (with IOC off, see below) and that's where she will return, within reason, no obstructions and enough battery left that is.

@ N017RW - You're getting 2 sets of Green flashing in NAZA-M because your IOC is enabled. No IOC means no Green flashing for the Forward Direction recording, just one set of flashing for Home Point saved after 6+ Sats are locked.

N017RW · Nov 15, 2014

RDCF550 said:
@ promocop - No offense intended. Rapid Green flashes = Ready to Fly in Phantom 2 Mode or NAZA-M (with IOC off, see below) and that's where she will return, within reason, no obstructions and enough battery left that is.

@ N017RW - You're getting 2 sets of Green flashing in NAZA-M because your IOC is enabled. No IOC means no Green flashing for the Forward Direction recording, just one set of flashing for Home Point saved after 6+ Sats are locked.

With all do respect I disagree.
Please provide documentation.

RDCF550 · Nov 15, 2014

Turn you IOC off (unchecked in the assistant) and take your P2nv NAZA-M outside, you'll get some pretty good documentation as well as only 1 set of Green flashing after 6+ Sats.

P2nv in NAZA-M with IOC disabled you will only get 1 set of rapid Green flashes, because there is no need to record the Forward Direction for the IOC. With IOC enabled, then you get the Forward Direction flashing as well as the flashing for Home Lock after 6+ Sats.

RobertMfromLI · Nov 15, 2014

N017RW said:
Not to be too nit-picky...(for a P2 [non-vision] in Naza Mode)

The first set of rapid green flashes indicates the heading or forward facing direction has been recorded/stored/etc. (for Course lock).

The second set of rapidly green flashing lights indicates GPS has acquired 6 or more satellites.

Sometimes the two sets of rapid flashing green can happen somewhat simultaneously and you get a single extended period of rapid green flashes.
(In this case I usually start over to be sure)

So far, virtually always for me. I was flying with someone else (not simultaneously... but one after the other, alternating copter and remote entirely off while other pilot flying), and his went from the "yellow" to "Course lock" almost immediately, and then proceeded as you said, over a few more seconds. This happened each of the three times I have seen him fly - I don't know if it ALWAYS happens this way for him or not.

Mine always seems to "take forever" for the first set of greens... but runs through all of them at once, giving, as you noted, the appearance of one long set of quickly flashing greens. Every time. Weird.

We both launched from the exact same spot.

Prylar Bek · Nov 15, 2014

This is getting confusing! Anyway, in the real world, how close will she return utilizing Failsafe (RTH) within 10 ft.?

sergekouper · Nov 15, 2014

Return home=3feet. and a smile.

RDCF550 · Nov 15, 2014

Yes, you can expect it to return within that distance or so, all things working correctly that is.

To sum this whole rapid Green flashing LED thing up..

Phantom Mode = Only 1 set of rapid Green flashing. Means 6+ Satellites and Home Position is set, and that's where it will return to, or there abouts.

NAZA-M Mode, with IOC disabled (IOC unchecked in DJI assistant) = Only 1 set of rapid flashing Green lights. Same as Phantom Mode, means 6+ Satellites and Home Position set.

NAZA-M Mode, with IOC enabled (IOC checked in DJI assistant) = You'll get 2 sets of rapid flashing Green lights. One means Forward Position has been recorded for the IOC, then the other means 6+ Satellites and Home Position set.

Prylar Bek · Nov 15, 2014

Got it Clear as rain!!!

SteveMann · Nov 15, 2014

Actually, quite clear and I appreciate it.

What I would REALLY like to see is an indicator on the iOSD that home is locked.

Question, if I take off and move a few yards from home and I see a value in the "D" (Distance from Home) in the iOSD, does that pretty well mean my home point is safe?

Prylar Bek · Nov 15, 2014

True I was being cheeky. I totally get it Thanks

AnselA · Nov 15, 2014

promocop said:
Sorry should have posted in PTV+ anyway I have READ it several times just trying to get practical answers. So next time I'll do thecalibration dance and get the home lock from exactly my launch point. Makes sense thanks

Calibration dance will calibrate the magnetic compass. It has no effect on home location, which is based on GPS.