+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...