Warning Re: Switching from Non GPS to GPS w/ new firmware

[Mickeyboo]

I've been out testing the new firmware updates for ST16 and also the H and in particular the ability to switch from GPS to Non GPS while flying. I was in a small open field for the test and only did it twice each time when switching back into GPS from Non GPS it caused the H to act strangely. This was all done with "Turtle" setting. Winds were dead calm with partly cloudy skies.

1. The first time I switched back from Non GPS to GPS while moving sideways at no greater a speed than
5 to 8 mph it shot across the field at about 25 to 30 mph for about 40 ft. I'm not sure why it stopped after that distance either my stick activity or it found where it liked to be in GPS.

2. The second try it moved vertically up and down about three or four feet with slight drift and then settled back into GPS.

When in Non GPS it flew very smoothly and going from GPS to Non GPS was not problematic, it merely resulted in a slow drift due to momentum.

Next week when I have time to return for more testing I'm going to a much larger field and testing so I can
try and see what produces the variance in it's behavior when switching from Non GPS to GPS. I hope others chime in on their experiences. I will also test with another H and H Pro. To see how behavior varies with three different drones. Perhaps my flight logs will reveal something as well. Another explanation could be the factory serviced repair I had done after the H took a dip in a glacial stream in Iceland perhaps it's still got some issues from that episode.

If your inexperienced at flying without GPS I would also use a large field to test how yours performs or not do it at all.

 

[banned user]

Watch out for the battery too, I've just switched it off in windy conditions flying downwind. After 15 seconds, saw the speed was 93kph, then 103kph, (64mph) decided 103kph was maybe a bit risky, switched back on GPS, immediately the battery waring came on, it was only up for about 5 mis from before. I would have thought no GPS = less battery use, but maybe at higher speeds fighting more stay level in windy conditions and drinking more juice?

 

[Luckyleaf]

Watch out for the battery too, I've just switched it off in windy conditions flying downwind. After 15 seconds, saw the speed was 93kph, then 103kph, (64mph) decided 103kph was maybe a bit risky, switched back on GPS, immediately the battery waring came on, it was only up for about 5 mis from before. I would have thought no GPS = less battery use, but maybe at higher speeds fighting more stay level in windy conditions and drinking more juice?

64 mph

 

[Mickeyboo]

64 mph

Did you switch back to GPS while flying?

 

[Mickeyboo]

Watch out for the battery too, I've just switched it off in windy conditions flying downwind. After 15 seconds, saw the speed was 93kph, then 103kph, (64mph) decided 103kph was maybe a bit risky, switched back on GPS, immediately the battery waring came on, it was only up for about 5 mis from before. I would have thought no GPS = less battery use, but maybe at higher speeds fighting more stay level in windy conditions and drinking more juice?

Did you switch back to GPS while flying smoothly (not at high speed)

 

[banned user]

Did you switch back to GPS while flying smoothly (not at high speed)

Yep, just as I looked down to see the speed I looked back at the H and the low voltage alarm went off, I immediately turned back on the GPS and after about another 10 seconds I checked the voltage and it had climbed back to about 14.8 or 14.9 - it stayed at that level and decreased like it normally would as I flew around for the next few minutes.
I'm thinking it could have gone faster, but that was my first time with the H to fly without GPS and it was a bit windy....like the kind of wind that you would not put a phantom out in..at that speed just a few seconds more and I could see it disappearing over the horizon.

 

[Mickeyboo]

Yep, just as I looked down to see the speed I looked back at the H and the low voltage alarm went off, I immediately turned back on the GPS and after about another 10 seconds I checked the voltage and it had climbed back to about 14.8 or 14.9 - it stayed at that level and decreased like it normally would as I flew around for the next few minutes.
I'm thinking it could have gone faster, but that was my first time with the H to fly without GPS and it was a bit windy....like the kind of wind that you would not put a phantom out in..at that speed just a few seconds more and I could see it disappearing over the horizon.

I wonder if mine is acting the way it does because it was not properly repaired at the factory after it took a swim in a glacial stream in Iceland...I guess I'll find out when I test the other ones I own.

 

[David Wilson]

So what is the top speed with GPS off now? Before the update I could get in the low 50's.

 

[banned user]

I wonder if mine is acting the way it does because it was not properly repaired at the factory after it took a swim in a glacial stream in Iceland...I guess I'll find out when I test the other ones I own.

I defiantly didn't switch modes while giving stick input, you said you switch while moving sideways, maybe thats a factor?

 

[Luckyleaf]

So what is the top speed with GPS off now? Before the update I could get in the low 50's.

Sounds like 64mph is the one to beat :]

 

[Sparkorc]

Generally operating any craft with no gps active it will just slide in the direction of the wind without any stick commands, so always be aware that when you stop putting any commands it will always continue in the direction of the wind, when I have re activated the gps before it has always arrested any movement and held its position without any stick commands, I have not tried this with the new update yet, because TH is with customer service at present.

 

[banned user]

Sounds like 64mph is the one to beat :]

I'm on island in the Atlantic off the coast of Ireland the so its always very windy here, I did have a huge push from the wind, it was about a 20-25mph, tail wind on it. I'm sure I could have gone more had it not been for the voltage alarm or being chicken of it going over the horizon, I might try it again tomorrow, that fast leg was only about 10 seconds long.

 

[banned user]

Generally operating any craft with no gps active it will just slide in the direction of the wind without any stick commands, so always be aware that when you stop putting any commands it will always continue in the direction of the wind, when I have re activated the gps before it has always arrested any movement and held its position without any stick commands, I have not tried this with the new update yet, because TH is with customer service at present.

Absolutely, with no stick input, when I switched off the GPS it took off in the wind at about the same speed that it normally moves at flat out in GPS.

 

[Sparkorc]

For those that have never flown with no gps, your best option try in a open space with no wind or very little also keep upwind, this will let you get the feel of the craft without any mishaps.

 

[Jimmylee]

How long does it take to switch back into GPS mode and get control back?

I just want to be prepared.

 

[banned user]

its instant

 

[Jimmylee]

its instant

Great! Thanks

 

[PatR]

It might be an idea to have the H stationary and on the ground when re-acquiring GPS. To have a moving platform attempt to get a position lock on a group of moving satellites just doesn't seem the best way to go about it. The circular error of precision has to be all over the map.

As for battery use, it makes absolute sense that as speed increases so then does energy consumption. I'm curious about something, though. If GPS was not functioning, what was used to establish the speed of the aircraft?

 

[banned user]

It might be an idea to have the H stationary and on the ground when re-acquiring GPS. To have a moving platform attempt to get a position lock on a group of moving satellites just doesn't seem the best way to go about it. The circular error of precision has to be all over the map.

As for battery use, it makes absolute sense that as speed increases so then does energy consumption. I'm curious about something, though. If GPS was not functioning, what was used to establish the speed of the aircraft?

For both I believe that GPS is not "not functioning" but is on and disengaged from giving input to the flight controller. This is allows transmission of aircraft coordinates to the ST16 and also allows immediate control once it is reapplied.

As for battery use, my speed increase was in large part due to a tail wind which was about half my ground speed, so using GPS traveling in the same downwind direction while the FC is using GPS to apply limits on the speed and heading I would have thought would have been less than the H just free drifting in the wind. Obviously not, it must do a lot of work to prevent it turtling.

 

[Mickeyboo]

its instant

I'm afraid in my case it was not "instant" on a dead calm day on turtle setting.. and prior to firmware update it flew calmly as well as with new fireware in Non GPS but it's the switching from Non GPS to GPS which caused erratic flying for several seconds and it manifested in two completely different ways on the two attempts...the first time it excellerated dramatically for 40 to 60 feet, the second time
it climbed vertically and came down vertically three or four times before it settled in. It could just be mine but everything was calibrated but it was recently factory repaired for water damage. That never happened when switching from attitude mode back to GPS mode with a Phantom.