Re: [Discuss-gnuradio] Scanoo Issue

[Mike Jameson]

Replies are inline below.  I've also CC'd the list.

On Wed, Jun 11, 2014 at 10:32 AM, Dimitris Siafarikas <address@hidden> wrote:

Mike,

I played a lot with Scanoo. I have a few questions.

1) Where is scanoo config file located?

The '.scanoo' file is probably in the same directory where you loaded 'gnuradio-companion' from. Do a search for it with:

sudo find / -name .scanoo

 

2) Why I get aU errors? The sample rate is small enough.

The aU errors occur when the audio block isn't getting a steady stream of 48k (default setting) samples per second. A small amount of samples are lost when switching modulation and when spectrum sensing due to the 'm in n' block.  To reduce this you can switch your CPU frequency scaling to performance mode.  You can also try forcing the audio sample rate in the audio sink block to be "int(audio_samp_rate*0.98)" which will make it expect 2% less samples and therefore significantly reduce audio underruns.

 

3) The spectrum sense feuture does not seem to work. It does not accurately print out the frequency. (I attached a prntscr.)

Your screenshot shows that you have blocked out 2GHz and so it should be locking on to the next strongest signal which is 150khz away from it.  This is defined with the 'bin_floor' variable which is at the very bottom right of the GRC flowgraph.

 

4) How it is supposed to sense at 127MHz (default) since my daughterboard’s range is 400 to 4400 MHz (SBX) ?

 The default center frequency of 127MHz is defined in the 'txt_center_freq' variable which is two boxes to the right of the audio sink.  It does not currently auto detect the frequency range of the daughterboard.  This is to make it more compatible with other SDR devices such as the RTL-SDR / HackRF which do not use the UHD.