hackrf: fix bandwidth setting

The T/R switching code added in ae2253c516
fails to set custom filter bandwidths because it sets bandwidth and
sample rate in the wrong order. As noted in the documentation for
hackrf_set_sample_rate: "If you want to override the baseband filter
selection, you must do so after setting the sample rate."

To solve this problem I moved the set_bandwidth call after
set_sample_rate. It was also necessary to skip the call if a custom
bandwidth was not requested.

Signed-off-by: Eric Wild <ewild@sysmocom.de>
This commit is contained in:
Clayton Smith 2020-12-31 21:34:51 -05:00 committed by Eric Wild
parent 9b386707d8
commit bc629b03fe
2 changed files with 5 additions and 1 deletions

View File

@ -37,6 +37,7 @@ hackrf_common::hackrf_common(const std::string &args) :
_center_freq(0),
_freq_corr(0),
_auto_gain(false),
_requested_bandwidth(0),
_bandwidth(0),
_bias(false),
_started(false)
@ -339,6 +340,7 @@ double hackrf_common::set_bandwidth( double bandwidth, size_t chan )
int ret;
// osmosdr::freq_range_t bandwidths = get_bandwidth_range( chan );
_requested_bandwidth = bandwidth;
if ( bandwidth == 0.0 ) /* bandwidth of 0 means automatic filter selection */
bandwidth = _sample_rate * 0.75; /* select narrower filters to prevent aliasing */
@ -411,9 +413,10 @@ bool hackrf_common::get_bias()
void hackrf_common::start()
{
_started = true;
set_bandwidth(get_bandwidth());
set_center_freq(get_center_freq());
set_sample_rate(get_sample_rate());
if (_requested_bandwidth != 0)
set_bandwidth(get_bandwidth());
set_gain(get_gain());
set_bias(get_bias());
}

View File

@ -104,6 +104,7 @@ private:
double _freq_corr;
bool _auto_gain;
double _amp_gain;
double _requested_bandwidth;
double _bandwidth;
bool _bias;
bool _started;