Problem with setting gain on BladeRF xA9 -- (tryin to run GNSS-SDR)

[patiklipenguen]

Hi,
I am trying to run GNSS-SDR with bladeRF xA9. However I'm facing some errors.

Here is the copy of terminal included errors:

[ERROR @ host/libraries/libbladeRF/src/board/bladerf2/rfic_fpga.c:553] _rfic_fpga_get_gain_stage: unknown gain stage 'LNA'
[bladeRF source] get_gain: Could not get gain for stage 'LNA': Invalid operation or parameter
Actual LNA Gain: 0.000000 dB...
[ERROR @ host/libraries/libbladeRF/src/board/bladerf2/rfic_fpga.c:553] _rfic_fpga_get_gain_stage: unknown gain stage 'VGA1'
[bladeRF source] get_gain: Could not get gain for stage 'VGA1': Invalid operation or parameter
Actual VGA1 Gain: 0.000000 dB...
[ERROR @ host/libraries/libbladeRF/src/board/bladerf2/rfic_fpga.c:553] _rfic_fpga_get_gain_stage: unknown gain stage 'VGA2'
[bladeRF source] get_gain: Could not get gain for stage 'VGA2': Invalid operation or parameter
Actual VGA2 Gain: 0.000000 dB...

It is quite obvious that the problem is about the gains. Because GNSS-SDR looking for LNA, VGA1, and VGA2 gains and I know that bladeRF xA9 only has a "full" gain setting. ( "On the bladeRF x40/x115, RX gain is implemented using three gain stages: LNA, rxvga1, and rxvga2. On the bladeRF xA4/xA9, there is one gain stage, full." )

So how can I change the gain settings in order to be able to work with bladeRF xA9 version? There is a config file in GNSS-SDR that controls LNA, VGA1, and VGA2 gains. When I comment on them, problems disappear. Even though problems disappear, still bladeRF xA9 not working correctly with GNSS-SDR. Because I can't control any gain. Also I tried to change gains with bladerf-cli and then run with GNSS-SDR.
I am not sure this problem is occurring because of the bladerf libraries or because of GNSS-SDR gain configurations and connection with bladeRF libs.
So how and where should I start to solve this problem?

Thank you.

[dkelly]

I see the same thing. No matter what I do, the BladeRF Micro gain seems to stay high (60).

I've tried setting it using bladeRF-cli, and I get a message "Note: This change will not be visible until the channel is enabled." Then I tried "rx config channel=1' to see if that does anything, and nope, gain still stays at high.

In GNSS-SDR, the gains seem to not work at all, so I leave them at 0. At least I'm getting GNSS-SDR to process bladeRF data, but gains are too high at 60 for my setup.

Any suggestions on how to set bladeRF micro gains appreciated!

[timothyferriss]

I see the same thing. No matter what I do, the BladeRF Micro gain seems to stay high (60).

I've tried setting it using bladeRF-cli, and I get a message "Note: This change will not be visible until the channel is enabled." Then I tried "rx config channel=1' to see if that does anything, and nope, gain still stays at high.

In GNSS-SDR, the gains seem to not work at all, so I leave them at 0. At least I'm getting GNSS-SDR to process bladeRF data, but gains are too high at 60 for my setup.

Any suggestions on how to set bladeRF micro gains appreciated!

Although bladeRF xA9 is a variant of bladeRF, there might be specific differences in how it's recognized or configured compared to other bladeRF models. retro bowl

[herrylauu]

Adjusting this value will control the gain for the BladeRF. A typical starting point might be 50-60 dB, but this varies with the environment and signal strength. Test different values to find the optimum balance between signal quality and noise. Sprunked