Skydemon and external BadElf Pro+ GPS

[trapdoor]

I'm still waiting for some of the bits to arrive from China and finally managed to source an ARF board as WirelessThings are out at the moment. So don't have a built working unit yet....

I was trying to get my head round how the GPS data is derived using Skydemon as the manual states for running with FLARM:

You will find the options for connecting to the Air Connect device in the Setup menu under Connectivity Options > FLARM, and once a connection has been established just tap the Go Flying button in the top right-hand corner of the toolbar and choose ‘Use FLARM’. A GPS fix will be obtained through your FLARM unit rather than your tablet/phone's GPS chipset
or external Bluetooth GPS receiver, and SkyDemon's GPS navigation
features will continue to function as normal, but with the addition
of traffic data.

I use an external Bad Elf Pro+ GPS via Bluetooth as it's a more accurate and reliable data source than the in-built GPS. So if SD no longer takes data from the Location Services data stream does the P3i app grab this data from the iOS 'location services', pipe it to the PilotAware box which then sends this data back via the Wifi hotspot along with the PilotAware confliction data?

Sorry if this is a daft question but just want to understand how the GPS data gets to (and from) the PilotAware system from either the I-device or an external GPS.

Mark.

[Admin]

Hi Mark,

There is an App I created, you will need to run on the iPad called CollisionAware.
https://itunes.apple.com/us/app/pilot3i-collisionaware/id960391094?mt=8

This app uses the iPad Location Services information, and provides to PilotAware.

PilotAware provides all information to SkyDemon, including your own position
and surrounding traffic.

OK, so the way badElf works (so I am told) is as follows, whenever a badElf device
is connected to the iPad, Location Services uses the data from badElf, rather
than using its own internal GPS, or WiFi location services.

So the intention is when you write an App for iOS, you simply ask for GPS data
without controlling the source of that data. When you connect a badElf IT becomes
the source of the data, as opposed to the internal GPS.

I will be interested in your results, because I have heard mixed stories about using
external GPS receivers, in particular using the Garmin Glo a couple of users have
reported issues with lost GPS signals. This is still to be determined as what is happening
some users see no issues, yet others do.

Thx
Lee

[trapdoor]

Hi Lee,

Happy to give feedback once my unit is built. I'm located close to Bristol Airport and also have a PCAS unit so can do direct comparisons on the ADS/B data off CAT (the PCAS identifies that), but also fly out of Kemble so would be interested to see how that fares.

Re. the Bad Elf, I was keen to know from them before I bought the Pro+ how iOS arbitrated Bluetooth and Internal GPS data, and evidently it uses the GPS accuracy (is it DOP data?) to always use the most accurate fix if both the internal and an external GPS are providing data to Location Services. It is certainly true that the Bad Elf Pro+ gives consistently better data, fewer dropouts (seen usually as a 'dive to earth' followed by a climb to correct height again) in the SD logs, but I'm just slightly cautious as to whether PilotAware and the CollisionAware app does the same thing as SkyDemon in that it takes the most accurate data to use and then fling back at the SD app.

Mark.

[Winged_Jaguar]

Just for info for Bad Elf users: the Bad Elf 2300 GPS+ supports both NMEA and Bluetooth. You can connect the Bad Elf to the Pi via a USB cable and it works. You can also have the Bluetooth on on the Bad Elf so that at any stage in SkyDemon you can switch from FLARM to using the GPS directly on the iPad (although hopefully we won't need to do that too often).

Great project!!: keep up the good work.

ps. The PilotAware units could also be attached to large structures such as TV Masts and other features although I haven't checked if the P3i standard allows the message to differentiate between point items such as planes, and masts which have location, height and depth. It would also be useful later on to be able to differentiate between gliders, balloons, singles, twins and fixed items to be able to get programmes like Skydemon to alter the graphic (which it can already do to an extent)

 

[Admin]

The PilotAware units could also be attached to large structures such as TV Masts and other features although I haven't checked if the P3i standard allows the message to differentiate between point items such as planes, and masts which have location, height and depth. It would also be useful later on to be able to differentiate between gliders, balloons, singles, twins and fixed items to be able to get programmes like Skydemon to alter the graphic (which it can already do to an extent)

Yes we have been thinking about static objects, in addition to moving objects, and to answer your question part of the protocol encodes what the object is, so yes you can differentiate.
For Static objects we have thought about a simpler system, because of course it does not need to have a WiFi or ADS-B, so in effect something like an Arduino would probably suffice
thx
Lee

[Admin]

Just for info for Bad Elf users: the Bad Elf 2300 GPS+ supports both NMEA and Bluetooth. You can connect the Bad Elf to the Pi via a USB cable and it works

Can I ask, as what does the device report itself ?
if you look at the web page 192.168.1.1, it will list the USB devices, I would be interested to know how this appears

Also, did you have to configure the GPS in PAW (ie, interpreted as an RS232 device), or did the device auto-configure ?

Thx
Lee

[Winged_Jaguar]

The Bad Elf GPS+ (BE-GPS-2300) appears in the USB list as "SGS Thomson Microelectronics".
In the GPS Sentences (USB) it appears as Msgs=<number> (+<number>) Fix="DGPS  fix" Mode="Undefined" Satellites=<number> {where 'number' is the relevant count}

I needed to make no configuration changes to make it work, just plug and go (the USB can be added and removed on a running system). I have the "ElfPort (tm) speed" set to 'Default' in the Bad Elf Advanced configuration menu