+x

 

neubamat - 8/27/2018 8:00:39 AM

I had to add corrections for geoid separation and baro pressure. Traffic's real baro pressure might be different if there's a big difference in altitude, but it should be accurate as long as we're on the same level within several hundreds of feet.

Yesterday was a good day for testing because my local QNH was about 1018 hPa. All flarm devices on the ground were displayed as on the ground

Change the altitude block in func processAprsData of /root/stratux/main/flarm.go to this one:

// set altitude
ti.Alt = int32(data.Altitude)
ti.Alt = ti.Alt - int32(mySituation.GPSGeoidSep) // fix geoid sep
ti.Alt = ti.Alt - int32(mySituation.GPSAltitudeMSL) + int32(mySituation.BaroPressureAltitude) // calc traffic's baro alt
ti.AltIsGNSS = false
ti.Last_alt = stratuxClock.Time

+x

 

neubamat - 8/27/2018 5:57:37 PM

The first one should be good for SkyDemon. Other apps may break, because they're using GDL90 not in the specified way. There should be a config switch to handle both variants. ForeFlight is able to use both ones if configured properly using a proprietary GDL90 message (Capabilities mask, https://www.foreflight.com/connect/spec/).

The second one doesn't handle the condition when no baro sensor is installed... but traffic alerts without your own baro alt don't make sense (at least for GDL90). The lowest known QNH is about 870 hPa (3861ft off) and the highest one was 1084 hPa (1917ft off).

+x

 

neubamat - 8/27/2018 5:57:37 PM

The first one should be good for SkyDemon. Other apps may break, because they're using GDL90 not in the specified way. There should be a config switch to handle both variants. ForeFlight is able to use both ones if configured properly using a proprietary GDL90 message (Capabilities mask, https://www.foreflight.com/connect/spec/).

The second one doesn't handle the condition when no baro sensor is installed... but traffic alerts without your own baro alt don't make sense (at least for GDL90). The lowest known QNH is about 870 hPa (3861ft off) and the highest one was 1084 hPa (1917ft off).

+x

 

TouchTheSky - 8/31/2018 8:33:29 AM

+x

 

neubamat - 8/27/2018 5:57:37 PM

The first one should be good for SkyDemon. Other apps may break, because they're using GDL90 not in the specified way. There should be a config switch to handle both variants. ForeFlight is able to use both ones if configured properly using a proprietary GDL90 message (Capabilities mask, https://www.foreflight.com/connect/spec/).

The second one doesn't handle the condition when no baro sensor is installed... but traffic alerts without your own baro alt don't make sense (at least for GDL90). The lowest known QNH is about 870 hPa (3861ft off) and the highest one was 1084 hPa (1917ft off).

Can you point me to the Stratux source code file where this FF proprietary GDL90 message (Capabilities mask) is set? SD and other EFBs ignore this mask, right? I would actually like to make sure that this Capabilities mask ist set to the standard value so that both SD and FF could be used with your suggested modifications.

[edit]: I found in gen_gdl90.go the following:

msg[38] = 0x01 // Capabilities mask. MSL altitude for Ownship Geometric report.

Shouldn't this be changed to:

msg[38] = 0x00

With this and your other suggested changes, both SD and FF should be working properly, right?

+x

 

neubamat - 8/31/2018 10:03:39 AM

+x

 

TouchTheSky - 8/31/2018 8:33:29 AM

+x

 

neubamat - 8/27/2018 5:57:37 PM

The first one should be good for SkyDemon. Other apps may break, because they're using GDL90 not in the specified way. There should be a config switch to handle both variants. ForeFlight is able to use both ones if configured properly using a proprietary GDL90 message (Capabilities mask, https://www.foreflight.com/connect/spec/).

The second one doesn't handle the condition when no baro sensor is installed... but traffic alerts without your own baro alt don't make sense (at least for GDL90). The lowest known QNH is about 870 hPa (3861ft off) and the highest one was 1084 hPa (1917ft off).

Can you point me to the Stratux source code file where this FF proprietary GDL90 message (Capabilities mask) is set? SD and other EFBs ignore this mask, right? I would actually like to make sure that this Capabilities mask ist set to the standard value so that both SD and FF could be used with your suggested modifications.

[edit]: I found in gen_gdl90.go the following:

msg[38] = 0x01 // Capabilities mask. MSL altitude for Ownship Geometric report.

Shouldn't this be changed to:

msg[38] = 0x00

With this and your other suggested changes, both SD and FF should be working properly, right?

Yes, that's it. Since I don't have FF... a FF user should verify that it is working properly. Probably other EFBs will still have issues...

+x

 

neubamat - 8/31/2018 1:18:39 PM

To enable Stratux and Internet access simultaneously on iOS, uncomment "option routers" and "option domain-name-servers" at the bottom of /etc/dhcp/dhcpd.conf

This doesn't improve anything on Android, unfortunately... but it still works as before

+x

 

TouchTheSky - 8/31/2018 2:33:28 PM

+x

 

neubamat - 8/31/2018 1:18:39 PM

To enable Stratux and Internet access simultaneously on iOS, uncomment "option routers" and "option domain-name-servers" at the bottom of /etc/dhcp/dhcpd.conf

This doesn't improve anything on Android, unfortunately... but it still works as before

You mean like this?

subnet 192.168.10.0 netmask 255.255.255.0 {
   range 192.168.10.10 192.168.10.50;
   option broadcast-address 192.168.10.255;
#    option routers 192.168.10.1;
   default-lease-time 12000;
   max-lease-time 12000;
   option domain-name "stratux.local";
#    option domain-name-servers 4.2.2.2;
}