Inter-display data

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GordonTurner
Posts: 21
Joined: Mon Oct 13, 2014 5:31 pm

Inter-display data

Post by GordonTurner »

Where can I find the data stream sentences for the inter-display links, both the Ethernet main link and the serial link between HXr and Mini-X? Specifically what I would like to find is if angle-of-attack (sensed) is transmitted in this stream?
MolsonB
Posts: 78
Joined: Fri Apr 10, 2015 1:53 am

Re: Inter-display data

Post by MolsonB »

I have some info here on the serial data. FrameFlags, char stuffing, etc
http://www.grtavionics.com/forum/viewto ... f=21&t=554

I have not run across the angle-of-attack yet.
GordonTurner
Posts: 21
Joined: Mon Oct 13, 2014 5:31 pm

Re: Inter-display data

Post by GordonTurner »

Thanks Molson. I'll need to study that a little more but from the data types and detail I'm seeing my guess is AOA information is probably not in the link.

Gordon
GRT_Jeff
Posts: 634
Joined: Tue Dec 11, 2012 12:11 am

Re: Inter-display data

Post by GRT_Jeff »

If the display unit has measured AOA and is configured to send it over the link, it will send the AOA normalized to a stall at 15 degrees, meaning a value >= 15 is at stall.

Packet type 16.
Byte 0: 3 (AOA data packet)
Byte 1: Bit field
Bit 0: This is measured data
Byte 2-5: Normalized AOA in degrees (32-bit float)

Or if you have a serial output available, you could use the V-Speed serial output, which is based on the measured AOA if available, and the estimated AOA if not.
GordonTurner
Posts: 21
Joined: Mon Oct 13, 2014 5:31 pm

Re: Inter-display data

Post by GordonTurner »

Wow. There it is.

Thanks Jeff.

Gordon
MolsonB
Posts: 78
Joined: Fri Apr 10, 2015 1:53 am

Re: Inter-display data

Post by MolsonB »

What is the best way going forwards with this? Should we sticky any packet breakdowns in another section, or just ask which ones we are looking for?
I'm looking for the IAS and baro/altitude (stuff sent to VPX), I have the GPS breakdown already to get the ground speed.
GRT_Jeff
Posts: 634
Joined: Tue Dec 11, 2012 12:11 am

Re: Inter-display data

Post by GRT_Jeff »

This thread or the other thread are fine. We can collect them together later.

The IAS and altitude are not sent over the link. In general, AHRS data is not sent over the link. This may change when we add the AHRS cross-check functions to the link, although that's mainly for roll and pitch.
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