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Inter-display data

Posted: Mon Dec 26, 2016 4:53 pm
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?

Re: Inter-display data

Posted: Tue Jan 03, 2017 8:26 pm
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.

Re: Inter-display data

Posted: Tue Jan 03, 2017 10:51 pm
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

Re: Inter-display data

Posted: Wed Jan 04, 2017 6:00 am
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.

Re: Inter-display data

Posted: Wed Jan 04, 2017 1:56 pm
by GordonTurner
Wow. There it is.

Thanks Jeff.

Gordon

Re: Inter-display data

Posted: Wed Jan 11, 2017 3:10 pm
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.

Re: Inter-display data

Posted: Thu Jan 12, 2017 6:24 am
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.