Show Posts

You can view here all posts made by this member. Note that you can only see posts made in areas to which you currently have access.


Messages - bladeslapper

Pages: [1] 2 3
1
General Discussion / Re: Bluetooth Adapters - Experiences/Recommendations
« on: October 26, 2021, 07:03:08 am »
...in my case to combine the audio warnings from PilotAware and from SkyDemon on my iPad mini...

Does SkyDemon not give audio alerts of traffic itself? I just assumed it would but have no direct experience of this.

2
@exfirepro

Good job putting all the words to go with my inappropriately brief post ;-)

3
This has made it loads better. Far fewer snags and hopefully I won't keep breaking the aerials with my headset bag now!

4
...if/when you have to operate at low level in mountainous terrain (like up here in Scotland) or in bad weather. You should see a definite improvement (or at least minimal deterioration) in those type of circumstances.

Most of my recent flights have been grovelling around in the Pennines with the cloud sitting across the summits so I guess it's had a pretty fair test and it's performed fine - there was 1 "network error" on the radar screen only which I couldn't explain but GNSS has been fine.

5
An update to this mod:

As was inevitable during another lock-down, I decided I might as well move the GNSS receiver even though there seemed to be surprisingly no problem with the antennae facing completely the wrong way!
I soldered an old USB lead onto the module headers and secured it under the Pi with some carefully placed high temp UHB tape and added kapton to protect from short against the Pi (just in case it managed to work loose). It actually wedges in the space where the square of small holes is without the UHB tape but better to be safe than sorry.

It's now facing completely up to the sky in the position as normally mounted in most of the helicopter I fly.

I've done a comparative analysis between the antennae facing the back of the battery and the inside of the helicopter vs where it is now and the number of visible satellites seems to be unaffected (around 9-12) but the acquisition time is now quicker and also the number of momentary "GPS data lost" incidents seems to have gone from 1 per flight to 0.

...therefore this is a worthwhile improvement (how could it not be?!?)


6
General Discussion / Re: EC Rebate - thoughts, time scales, etc...
« on: December 03, 2020, 11:09:56 am »
the money arrived in the bank today

 :)

7
Quote
Yes I completely agree but no that's pretty much the best we can do. It's the same in most helis.

Actually this isn't completely true, as discussed previously on this thread, mounting the unit upside down will result in the aerials being much more vertical but may add some visual obstruction issues. I thought I would try the simple and likely worst case scenario first but I will invert it next time and see how that is.

Quote
In that case, the easiest option to improve GPS fix would simply be to put the existing GPS dongle on a short USB extender and mount it on the top end of the case between the two antennas

That would be a nice solution, and in fact if it was inverted then it could go on the other end which could be much neater if I design and print a new end cap to slide on and contain the dongle.

I'm actually surprised at how well the dongle worked with the aerial facing completely the wrong way and insulated by a battery!
I've flown again for 2 hours since and these additional logs show that it could see an average of 10 sats and no loss of GPS data for both flights.

I still might move the dongle as I'm just curious to tinker!

8
Is it not feasible to fit the battery to the base and lay the unit flat with the GPS towards the window and then have the room to set the antennas to vertical further away from the screen. 

I have considered this also....on a long RAM mount attached to the window with a 3D printed adaptor for the battery to connect to Rosetta on one side and the Ram mount on the other. But, I suspect I will never bother with the hassle of carrying it around with me. It's already barely small enough to take on a day of work TBH

9

If you upload your track file to https://aircrew.co.uk/playback/

That's great, thanks. I looked at my outbound track and inbound track and strangely they were markedly different. Outbound (30 mins travelling west) between 5 and 8 sats and about 10 very brief moments of no GPS. Return leg East (generally) for 1 hour and between 9 and 12 sats and only 2 brief drop-outs.

I'm surprised the GPS receiver works as well as it did to be honest. I'll probably modify it anyway tho.....I can't help myself sometimes!

10
Hi Bladeslapper

So sorry to be negative about this but short of placing your unit in a metal or carbon fibre box it is hard to envisage a worse positioning of your unit.  Other than the position of your GPS which you have already acknowledged, your antennas are at such an angle as to be well out of phase with any incoming signals.  You will be broadcasting your P3i signal in roughly a doughnut shape at 90 degrees to the  length of your antenna and the majority of the forward transmission is angled upwards at apparently 45 degree, making it less likely for you to trigger a response from any groundstations you are approaching and seriously reducing the range of your air to air contacts I would think.  Rearwards you are broadcasting into a couple of bags of water and your aircraft interior whatever that my be made of.
Is it not feasible to fit the battery to the base and lay the unit flat with the GPS towards the window and then have the room to set the antennas to vertical further away from the screen. 

Regards
Alan

Yes I completely agree but no that's pretty much the best we can do. It's the same in most helis. I've done a few semi-permanent installs now and they are much better as we can position the Rosetta elsewhere. Don't forget that most helicopters cruise with a slight nose down attitude compared to when on the ground. Not by much I admit.

11
Update from today

I did a couple of hours in the heli today and the new arrangement seems to work fine despite the GPS receiver being in pretty much the worst possible position (see pic). The only thing I noticed were a few occasions where the traffic near me seemed to jump around. It did occur to me that this might be if I have lost position data and it jumped to assuming I was facing north?

How do I go about analysing the logs to quantify the quality of the GNSS data? I have them on my PC and open in notepad++ which I have identified as not ideal!

12
General Discussion / Re: EC Rebate - thoughts, time scales, etc...
« on: December 01, 2020, 10:50:12 pm »
yeah mine was pretty quick too. I was already signed up to the portal so that bit was easy. I uploaded the invoice just under 2 weeks ago and got the acceptance email through yesterday. Just awaiting the money to land now.

A cynic would comment - surprisingly quick for our authority.....

13
Thanks for the additional information. All my uses of PA so far have been installs I have done in helis using all 3 external antennae, in fact I posted details of an old one on here recently:
http://forum.pilotaware.com/index.php/topic,1974.0.html

I've never used the PA as a portable unit mainly because it isn't portable enough for my user case - hence this little project.

It's still working fine in the office window but I'll be sure to post details of how well it works once I get in the air again. Does the Pi log the GNSS reception 'quality' for post flight analysis ?



14
Thanks for the info. Yeah that was what I thought looked like the aerial.

Unfortunately the only option is to mount it on the inside of the screen/bubble either on its suckers or on a go-pro mount (I fly various heli types). The GPS aerial is therefore always going to be facing directly towards the front seats. With this in mind, while I was looking around inside the Rosetta, I was toying with the idea of moving the dongle to a better position but decided to leave it as is for now. There is plenty of space in there so I pondered turning the aerial to face the back/bottom and either leave it in the same compartment or perhaps put it under the Pi where the array of small holes are.

Having said that, I've had it attached to my office window for the past few days and it seems to be performing OK using only half the sky - currently using 6of12 sats. I have also tried turning the whole thing around 180 on the window so the dongle is at least at the top thinking this might improve GNSS reception but it doesn't seem to make a difference. I figured that having the aerials pointing straight down would be equally as good as straight up but I'm not certain about that?

One thing I did notice which was strange was apparent interference receiving GNSS data with the dongle plugged into USB port 2 and the ADS-B adaptor in port 3. This meant that the ADS-B aerial wire had to pass directly over the dongle's antenna rather than under and this was the only thing that I could think might be the cause. I left it for 2 hours and it managed to get 3or4 satellites out of about 6 but never managed to get a fix. Any ideas?

15
Out of interest, when I was looking at the 'internal' GPS, I guessed that the aerial is on the side closest to the sticker/front of the rosetta? Is that correct?

Pages: [1] 2 3