One of them is a “filter.single_pole_iir_filter_ff” which does a moving
average. The last block is a Sink to file block.
I scan several bands, 10MHz each, in order to get the power of the
signals
in those bands. I use moving average to get an average of 5 readings in
each band.
In order to change the center frequency, I stop the flow-grahp,
reconfigure
the USRP center freq and then start the flow-graph again.
I guess samples from the previous scans remain in internal block buffers
since I get power in samples of BAND2 (BAND1+10MHz) which are only
present
in BAND1. That is, the moving average is effective between bands and I
only
want to be effective in the same band.
I thought that stop() and start() signals would reset the entire graph
but
I am afraid it doesn’t.
Is there a way to flush those samples so that everytime I run the
frequency
changed flow-graph I don’t get the samples from the previous band?
In order to change the center frequency, I stop the flow-grahp,
reconfigure the USRP center freq and then start the flow-graph again.
You can use the message port[1] in uhd source/sink or stream tags [2] to
change the center frequency
frequency changed flow-graph I don’t get the samples from the previous band?
UHD source will give rx_time, rx_rate and rx_freq tags whenever there is
a
tune request to a new frequency. You can use these tags to get rid of
unwanted samples.