[Discuss-gnuradio] How to capture the Rx data using uhd_rx_cfile and agree with the uhd_fft Scope mode data

[LD Zhang]

Hello community,

I am trying to use the uhd_rx_cfile command to capture some rx samples in the hope of recovering what I see as streaming samples in the uhd_fft Scope mode display. Since I am really new to GR+USRP, I have a couple of difficulties:

1. The uhd_rx_cfile command help menu does not provide a BW option
2. When using the uhd_rx_cfile command and specifying a frequency, it seems to record a sinusoid, again possibly a bw issue. However, I am not quite sure whether I am looking at the same signal port input. I intend to look at LFRX daughter board port B input.
3. I have not been able to reproduce what I saw in the uhd_fft Scope mode streaming data. Without any gain, I am seeing streaming data at a level of +/- 200 units, which may be reasonable noise. How do I capture the same data into a file. Since my difficulty with "uhd_rx_cfile" command, hence this question. I have also experimented with the "rx_samples_to_file" command with worse experience.

I could go directly to GRC GUI directly and try to learn to do everything there. But I think there is value in being able to do this simple thing from the command line. Your help and suggestions are appreciated.

LD Zhang