What i dont understand about fly aways with RTH

[Aqeel200]

i know what you mean..I am too afraid of a flyaway bro, thats why

Anyhow I adopt a preflight checklist. one of it is just to hover about 5', drag the phantom a few feet away..and see if it goes back to where it was..if it does, then i dont calibrate the compas. if it doesnt, then I land it and calibrate it again. I always fly in GPS mode as I am a newbie with zero rc flying experience.

 

[DBS]

You guys talk about GPS like its so prone to error.
Yet on all the GPS devices i had, it knows when the lock on location is good and keeps it.
i never ever had my gps say im in a location where i am not.

Millions of people will say the same as you....

And millions of others will tell stories of how they see inaccuracies in their GPS devices all the time...

"It never happened to me" is not a reasonable answer to a problem people are trying to understand...

Having your GPS instrument strapped to a flying lawnmower full of vibrations and trying to rely on input from several other sensors to maintain it's accuracy multiple times per second... there's bound to be some trouble here and there :ugeek:

 

[Madwak]

You guys talk about GPS like its so prone to error.
Yet on all the GPS devices i had, it knows when the lock on location is good and keeps it.
i never ever had my gps say im in a location where i am not.
Ofcource it starts with a big area(probaly cell tower location) then quickly moves closer, then gets a 100% lock thats like 5 meters accurate.

The phantom appears to be just using pure GPS data to get its location and that information is not always available for example I put my phantom in my backyard a lot while testing things on my app and every time I have done it bar one it has achieved a good number of sats (7-8) and got homelock within 2 minutes. The one time that it didn't it was sat there for over half an hour while I was messing with camera settings and the available sats shown in the app was constantly changing from 4-6 but most of the time 4 :shock: the following day it was back to normal. My guess is there was a lot of solar flare activity on that day obscuring the satellite signals.

 

[RedRyderMedia]

Has nothing to do with rotors. When it gets sat lock it'll blink green real fast then blink green slow. Now you have your home point.
Really need to read manual.

I found this isn't true. If you move the Phantom after the slow flashing yellow turns to fast flashing green and then to slow flashing green, BEFORE YOU CSC OR TAKEOFF, the Phantom establishes a new home position where you move it. If you don't believe me, try it.

I went through the start sequence and after getting the slow flashing green, but BEFORE CSC, I picked the Phantom up and walked 100ft away. It established a new home after just a couple of seconds. It seems you need slow flashing lights AND something else to happen to get home lock.

 

[DBS]

Just watch the DJI flight instruction videos people... This is not a mystery... it is established and has been the same since the earlier versions of the phantom....

Let the phantom acquire satellites and change to slow flashing green lights... it now knows where it is and is ready to mark position

Position will be recorded as home point when launch is initiated and phantom leaves the ground... that is the takeoff point... that is the only thing stored in the Phantom memory for reference point to RTH... unless you change it by flipping S2 multiple times

 

[RedRyderMedia]

Just watch the DJI flight instruction videos people... This is not a mystery... it is established and has been the same since the earlier versions of the phantom....

Let the phantom acquire satellites and change to slow flashing green lights... it now knows where it is and is ready to mark position

Position will be recorded as home point when launch is initiated and phantom leaves the ground... that is the takeoff point... that is the only thing stored in the Phantom memory for reference point to RTH... unless you change it by flipping S2 multiple times

I agree now that home position isn't set until CSC or you takeoff, but page 41 of the P2V+ User Manual says:

"After successfully record the home point, rear LED flight indicators blink fast green."

The fast flashing green occurs before the slow flashing green Ready to Fly indication. This seems to say the fast flashing green indicates the home position is set. This I now believe is not true.

 

[Flighttime]

Just watch the DJI flight instruction videos people... This is not a mystery... it is established and has been the same since the earlier versions of the phantom....

Let the phantom acquire satellites and change to slow flashing green lights... it now knows where it is and is ready to mark position

Position will be recorded as home point when launch is initiated and phantom leaves the ground... that is the takeoff point... that is the only thing stored in the Phantom memory for reference point to RTH... unless you change it by flipping S2 multiple times

I agree now that home position isn't set until CSC or you takeoff, but page 41 of the P2V+ User Manual says:

"After successfully record the home point, rear LED flight indicators blink fast green."

The fast flashing green occurs before the slow flashing green Ready to Fly indication. This seems to say the fast flashing green indicates the home position is set. This I now believe is not true.

Another thing worth noting...fast flashing green on the phantom rear LEDs also indicates when your smartphone successfully connects via WiFi. This isn't stated in the manual but is something I've observed on both the P2V+ and P2V

 

[Geoelectro]

I believe the first set of quick blinking green lights means it has locked the heading for coarse lock. (Which way the craft is pointing) the home lock is locked at take off.

Geo

 

[BlackTracer]

I am in 100% agreement with DBS's assessment of home point recording.

So what I think we have here (which someone validated) is the rapid greens (second set in NAZA) really means READY TO STORE the home point. The home point is not actually stored until you CSC. Or take off. Not sure if its take off or CSC. Need to test that (no offense DBS).

So if you get the greens and hand walk it 100 ft away and take off, the home point is where you left the ground, not where you got the greens. Great. Good to know.

So how do we know what point is actually stored? We just have to hope it is right where we just took off from for now until given another method. A quick check of the radar after take off will give you a good idea, as well as a quick RTH check.

Some think it doesnt matter anyways because if the locations (Phantom or home) get corrupted, it is going to fly away anyways somewhere in mid-flight, perhaps more often with v2.0 and above.

 

[DBSAM]

In the app, in the settings page, during my flight shows where my PV2+ is on a google map...

 

[MrC]

First set off rapid greens will happen exactly 30 seconds after power-on. Course lock position recorded (orientation of craft)

Seconds set of rapid greens usually happens just after it gets good sat lock (slowly flashing greens with no reds) This is it setting home position. The actual home position it sets is 20m above this point. I wait to get both before csc. Imo it sets homepoint at this time, not when you take off or csc. I will test next time im out.

 

[Flighttime]

For those who are still in doubt about the recording of home point after CSC. Have a read at page 15 of the Naza-M manual...and pre-empting the next question, it is applicable to Vision mode as well.

http://download.dji-innovations.com/dow ... .24_en.pdf

 

[Doono]

For those who are still in doubt about the recording of home point after CSC. Have a read at page 15 of the Naza-M manual...and pre-empting the next question, it is applicable to Vision mode as well.

http://download.dji-innovations.com/dow ... .24_en.pdf

Very good.

 

[AnselA]

Have a read at page 15 of the Naza-M manual...and pre-empting the next question, it is applicable to Vision mode as well.

"* Important: Naza-M, Naza-M V2 and PHANTOM control system are different in hardware parts, but their
configurations and functions are the same when using the same Assistant Software and Firmware Version, so they
use the same Guide. Unless stated, the following instruction is basic on Naza-M V2. If you use the Naza-M, please
make sure to read the “Instruction of V1 (also known as Naza-M)” section; if you use the PHANTOM, download the
other corresponding manuals on the PHANTOM web page."

???

 

[gunslinger]

I'm still confused about this and need to do some testing myself. I remember a recent post (I'll try to find it later and add it to this post) where someone acquired home lock under the shade of a tree, then moved a distance away and took off. He had an RTH and the aircraft landed in the tree that he was under before he initiated a CSC... In that case, home lock appeared to have occurred before the rotors spun...

-slinger

 

[AnselA]

I did an experiment:

• Took props off.
• Went out to my yard, where P2V has never been flown.
• Powered ON TX and extender
• Powered ON P2V and camera
  
• Waited until P2V was ready for GPS mode (slow blinking green)
• Powered ON Android
• Connected Android to Phantom WiFi
• Started Vision app 1.0.36 on Android
  
• Did CSC to start motors, let them run for about 15 seconds, then throttle down and motors shut off. NOTE: there was no lift off, 100% sure because no props.
• Changed Android WiFi connection to my WLAN -> internet
• In the app > Find My PHANTOM 2 VISION, which displayed Google map and located P2V accurately on the map.
  
• Powered OFF P2V and camera
• Powered OFF TX and extender
• Powered OFF Android
  
• Powered ON Android, which by default connected to my WiFi/internet
• Started Vision app 1.0.36 on Android
• In the app > Find My PHANTOM 2 VISION, which displayed Google map and the same location for P2V as before

Conclusion: Vision app will save P2V location in non volatile memory

 

[doug86]

home positon not related to take off altitude

see this great little experiment:

https://www.youtube.com/watch?v=3Cd9DQO9w0Q

 

[garrock]

Re: home positon not related to take off altitude

see this great little experiment:

https://www.youtube.com/watch?v=3Cd9DQO9w0Q

Should try taking off from the top of the ladder; perhaps home is marked once the rotors are fired up.

 

[Flighttime]

Home point is recorded in coordinates.

See this viewtopic.php?t=6542

Landing is by "feel"