Do data from Dongle

FlightAware ADS-B Flight Tracking
1

After upgrade to PiAware 3, I am getting reports of my receiver not providing data to FlightAware. The logs show the following:


Oct 24 14:41:51 piaware dump1090-fa[424]: weirdness: rtlsdr gave us a block with an unusual size (got 0 bytes, expected 262144 bytes)
Oct 24 14:41:51 piaware dump1090-fa[424]: weirdness: rtlsdr gave us a block with an unusual size (got 0 bytes, expected 262144 bytes)
Oct 24 14:41:51 piaware dump1090-fa[424]: weirdness: rtlsdr gave us a block with an unusual size (got 0 bytes, expected 262144 bytes)
Oct 24 14:41:51 piaware dump1090-fa[424]: weirdness: rtlsdr gave us a block with an unusual size (got 0 bytes, expected 262144 bytes)
Oct 24 14:41:51 piaware dump1090-fa[424]: Mon Oct 24 14:41:51 2016 UTC  No data received from the dongle for a long time, it may have wedged
Oct 24 14:43:16 piaware dump1090-fa[424]: Mon Oct 24 14:43:16 2016 UTC  No data received from the dongle for a long time, it may have wedged
Oct 24 14:44:17 piaware dump1090-fa[424]: Mon Oct 24 14:44:17 2016 UTC  No data received from the dongle for a long time, it may have wedged
Oct 24 14:45:17 piaware dump1090-fa[424]: Mon Oct 24 14:45:17 2016 UTC  No data received from the dongle for a long time, it may have wedged
Oct 24 14:46:18 piaware dump1090-fa[424]: Mon Oct 24 14:46:18 2016 UTC  No data received from the dongle for a long time, it may have wedged
Oct 24 14:47:19 piaware dump1090-fa[424]: Mon Oct 24 14:47:19 2016 UTC  No data received from the dongle for a long time, it may have wedged

A quick search of the internets doesn’t result in anything about a wedge. What is that and what does it mean. More importantly, can I clear that error? I’ve rebooted/powered down the Raspberry Pi and it still doesn’t work.

2

Could be a faulty dongle, bad power, or a bad USB connection.

The error means that dump1090 is not receiving any samples from the dongle (in normal operation it’s receiving 2.4M/s…)

Older dump1090 versions would just silently stop working if this happened, the newer version notices it and complains.

3

Figured that. Is there any built in tool in the 3.x image that can test the dongle or a tool I can install.

4

You could try rtl_test (“rtl_test -s 2400000” after stopping dump1090)

5

It only loses samples at the very beginning of the test (returns one line of loss). I’m running the -p test and it is showing a real sample rate of ~2048000 with a cumulative PPM averaging about 80.

I’m not an SDR expert but it looks like it is communicating OK. Anything else to check on the software side before I go purchasing and swapping hardware/cables?

6

Check it at 2.4MHz because that’s what dump1090 uses.

7

I initially ran it per your suggestion:

rtl_test -s 2400000

That came back with only one line of loss during multiple minutes of test. During the -p test, it stopped after a minute or so. I’m going to assume the SDR has died. It’s only been in the unconditioned attic for a couple years.

Thanks for your help.