SkyDemon Forums

GDL 90 support

http://forums.skydemon.aero/Topic27229.aspx

By Aleksei - 10/22/2018 8:44:56 AM

Hi.

I am new to SD and am currently using the 30-day trial version Sky Demon on an Android tablet on the ground yet.
I have self-developed ADS-B receiver with built-in GPS.
I would like to send messages about the location of my device and traffic messages to the SD using the protocol of the GDL90, but so far there are problems.

Every second l send "Heartbeat" message and it seems to be perceived by the SD, the beat as a message about the timeout does not appear .
I make such a conclusion, on the basis of that, if I cease to transmit "Heartbeat" message, then in SD a message about reception timeout appears ( " no data has been received from your gps device...").

Together with the "Heartbeat" message, I send "Ownship report" message with my location, but for some reason it is not perceived by the SD.
After the start of the "Go Flying", a message "Сonnects to device" appears, and then "GPS lost" message appears.

Moreover, "GPS lost" message appear both in the case of the transfer of only one type of message - "Heartbeat" message, and in the case of the transmission of a pair of messages to the "Heartbeat" message and the "Ownship report" message.

Perhaps something is wrong with the messages format?
I am putting his example here, including a checksum:

"Heartbeat" message
0000: 7e 00 81 41 5b 76 00 00
0008: 05 4d 7e

"Ownship report" message
0000: 7e 0a 01 12 34 56 2a a5
0008: f9 15 90 03 03 6a a9 00
0010: 00 00 bd 01 31 31 31 31
0018: 32 32 32 32 00 fd 18 7e

"Heartbeat" message
0000: 7e 00 81 41 5d 76 00 00
0008: a3 e7 7e

"Ownship report" message
0000: 7e 0a 01 12 34 56 2a a5
0008: f9 15 90 03 03 6a a9 00
0010: 00 00 b6 01 31 31 31 31
0018: 32 32 32 32 00 46 1c 7e


Messages are send to port 127.0.0.1:4000
In the SD settings, support for the protocol GDL90 is selected (SkyEcho, iLevil and other GDL-compatible devices).

I would be grateful for any advice

By Tim Dawson - 10/29/2018 12:17:45 PM

So buy yourself a GDL90 device, or borrow one.