FlightAware Discussions

Adding UAT to existing 1090 dropped plane count

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.

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:

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.

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.

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.

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)

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