FlightAware Discussions

Adding UAT to existing 1090 dropped plane count

FlightAware ADS-B Flight Tracking
#1

I’ll start with I’m fairly new to this. I built a ADS-B receiver on a Raspberry Pi 2B running Raspbian Buster running the flight aware add on with a FA Pro Plus receiver connected directly to the Pi 2B, with a home made cantenna connected via a 3ft F to SMA cable. I’ll also add since the Pi 2B does not have built in Wifi I’m using a Edimax EW-7811Un 2.5Ghz WIFI dongle also directly connected to the Pi 2B.

This setup seems to work pretty well.

I decided to add a 2nd receiver to pick up UAT as I have a few GA airports within 20 miles.

The second receiver I built a 2nd cantenna (for 978Mhz) connected via 3ft F to SMA cable to a FA 978/1090 filter, connected to a FA Pro receiver connected via a USB extension cable. I installed dump978, serialized the receivers, enabled UAT.

My antennas are at the same height roughly 24" apart.

The issue I noticed is adding the UAT receiver dropped my 1090 plane count about 25%.

If I unplug the 978 receiver, my 1090 plane count returns to normal, if I plug it back in, it drops again.

I tried both a 1ft and 3ft USB extension cable on the 2nd receiver with the same results.

I searched the board and saw similar topics but none with any definite cause or fix.

I did a scan on both receivers and there is high noise from 860Mhz to 894Mhz on the 1090 receiver (FA Pro Plus) and from 862Mhz - 878Mhz on the 978 receiver (FA Pro)

Any thoughts?

I attempted tom move the 978 receiver (FA Pro) to a 2nd Raspberry Pi, by installing dump978-fa there and pointing Skywawre978 on the Pi 2B to it as the feed but while I did see UAT traffic on the local
/skyaware978 dash of the Pi 2B, the data never made it to FA.

#2

That’s not capable enough or two SDRs, not enough CPU.
Not sure it will run 978 on its own even.

Then you configured it wrong.
Configure piaware to uat-receiver other and give the relevant ip and port for uat-receiver-host and uat-receiver-port …
You’ll figure it out :slight_smile:

#3

Hmm, 2B should have enough CPU, it’s a quad core, top (with shift I) shows dump1090-fa using about 30% (of a core) and dump978-fa using 45% (of a core) total CPU is well under 100% of a single core.

#4

Oh … thought it was the once core, the quad core should suffice indeed.

Then it’s voltage sag probably :slight_smile:
Powered USB hub could solve the issue i suppose.
Better power supply for the Pi might be sufficient.

#5

I think you did point me in the correct direction for getting 978 data from the 2nd Pi.

Pi1 - disabled dump978-fa

Edited flightaware978 to point to pi2

Edited piaware.conf
uat-receiver-type other
uat-receiver-host pi2

the FA logs look better

[2020-12-27 08:10 EST] Started faup978 (pid 508) to connect to the ADS-B data program at pi2/30978
[2020-12-27 08:10 EST] Starting faup978: /usr/lib/piaware/helpers/faup978 --connect pi2:30978

[2020-12-27 08:10 EST] 182 msgs recv’d from dump1090-fa; 182 msgs sent to FlightAware
[2020-12-27 08:10 EST] 0 msgs recv’d from the ADS-B data program at pi2/30978; 0 msgs sent to FlightAware

Now I just need some UAT traffic to confirm it’s working.

#6

Then it’s voltage sag probably :slight_smile:
Powered USB hub could solve the issue i suppose.
Better power supply for the Pi might be sufficient.

This was my first thought as I had lost the original Pi2 PSU and was using a Samsung phone charger (2A), bought an official Pi PSU (2.5A) but it didn’t help (but at least I have the correct PSU now)

#7

It could still be the Pi2 USB voltage circuitry being insufficient.
It’s not a straight shot to the power supply.