No decode on BladeRF A4

[hexagonal-sun]

Hello!

I'm having issues using the BladeRF-A4 to decode ADSB messages. Everything seems okay on the command line (I get no errors), however no messages are ever decoded. I know that the antenna I'm using is able to decode ADSB as it works fine with an RTL-SDR. I've also tried plugging in the antenna to both RX ports on the A4.

I also see the D1 LED flashing, so something is happening.

Is there anything I could do to help debug the problem?

Thanks!

[knodtradamus]

On the original bladeRF device, I had to play around with gain settings on the command line to get ADSB decoding to work. The bladeRF_adsb program doesn't provide usage statement, but you can examine the bladeRF_adsb.c source to see what it accepts. For convenience, I'll put it here as well:
bladeRF_adsb [LNA_GAIN] [RX_VGA1] [RX_VGA2]
where:
LNA_GAIN = {min, mid, max, unified}
RX_VGA1 = Gain (dB) of first stage after LNA
RX_VGA2 = Gain (dB) of second stage after filter

I was able to use:
bladeRF_adsb mid 25 25

It looks like the "unified" option is intended for the newer blade devices (and seems to work with the older too?) . If that is set, from looking at the source code, it appears that will set this unified gain level to 35 dB. So just like this:
bladeRF_adsb unified

The source shows that should be the default behavior for the A4 anyway. However, it doesn't look like this 35 dB setting is available to modify from the command line, but you could change it in the source and rebuild the utility to try it at other levels.

[hammy]

I'm having issues using the BladeRF-A4 to decode ADSB messages. Everything seems okay on the command line (I get no errors), however no messages are ever decoded. I know that the antenna I'm using is able to decode ADSB as it works fine with an RTL-SDR. I've also tried plugging in the antenna to both RX ports on the A4.

I had the same problem too trying to use the FPGA adsb build.
Antenna/lna combo works great with rtl and ettus b210 sdr's and even a bladerf v1 (with adsb fpga firmware). I looked into the host sw and nothing was getting transferred to it. This was using the adsbxA4.rbf downloaded from the nuand website https://www.nuand.com/fpga_images/. It reports as v0.8.

I'm on ubuntu 20.04, using the nuand ppa (libbladerf v2.2.1 & fpga v0.11.0) with a bladeRF 2.0 micro A4.
I did a compile from source for the adsb fpga image, set to v0.11.0 (git checkout fpga_v0.11.1) using the build instructions on https://github.com/Nuand/bladeRF-adsb#building-ads-b-image, and now it works.

sean