[PATCH] rfspace: Add PPM correction

From: Clayton Smith &lt;argilo(a)gmail.com&gt; This patch was originally written by Alexandru Csete and posted at https://github.com/csete/gr-osmosdr-gqrx/commit/d66df300. The only change I made was to rename the _freq_corr_ppm variable to _freq_corr, since many other devices use that name. This patch used to be included in Gqrx releases, so it should work correctly. --- lib/rfspace/rfspace_source_c.cc | 17 +++++++++++++---- lib/rfspace/rfspace_source_c.h | 2 ++ 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/lib/rfspace/rfspace_source_c.cc b/lib/rfspace/rfspace_source_c.cc index 314dfc732d..113588a5d4 100644 --- a/lib/rfspace/rfspace_source_c.cc +++ b/lib/rfspace/rfspace_source_c.cc @@ -103,6 +103,7 @@ rfspace_source_c::rfspace_source_c (const std::string &args) _nchan(1), _sample_rate(NAN), _bandwidth(0.0f), + _freq_corr(0.0), _fifo(NULL) { std::string host = ""; @@ -446,6 +447,8 @@ rfspace_source_c::rfspace_source_c (const std::string &args) _thread = gr::thread::thread( boost::bind(&rfspace_source_c::tcp_keepalive_task, this) ); } + _center_freq = get_center_freq(); + #if 0 std::cerr << "sample_rates: " << get_sample_rates().to_pp_string() << std::endl; std::cerr << "sample rate: " << (uint32_t)get_sample_rate() << std::endl; @@ -600,7 +603,7 @@ static size_t read_bytes( int fd, char *data, size_t size, bool &run ) int nread = read( fd, &data[nbytes], 1 ); if ( nread == 0 ) - continue; + continue; if ( nread < 0 ) break; @@ -1378,7 +1381,10 @@ osmosdr::freq_range_t rfspace_source_c::get_freq_range( size_t chan ) double rfspace_source_c::set_center_freq( double freq, size_t chan ) { - uint32_t u32_freq = freq; + uint32_t u32_freq; + + u32_freq = freq * (1.0 + _freq_corr * 0.000001); + _center_freq = freq; /* SDR-IQ 5.2.2 Receiver Frequency */ /* SDR-IP 4.2.2 Receiver Frequency */ @@ -1395,7 +1401,7 @@ double rfspace_source_c::set_center_freq( double freq, size_t chan ) transaction( tune, sizeof(tune) ); - return get_center_freq( chan ); + return _center_freq; } double rfspace_source_c::get_center_freq( size_t chan ) @@ -1423,12 +1429,15 @@ double rfspace_source_c::get_center_freq( size_t chan ) double rfspace_source_c::set_freq_corr( double ppm, size_t chan ) { + _freq_corr = ppm; + set_center_freq( _center_freq, chan ); + return get_freq_corr( chan ); } double rfspace_source_c::get_freq_corr( size_t chan ) { - return 0; + return _freq_corr; } std::vector<std::string> rfspace_source_c::get_gain_names( size_t chan ) diff --git a/lib/rfspace/rfspace_source_c.h b/lib/rfspace/rfspace_source_c.h index 996f47b392..42bb6de6ac 100644 --- a/lib/rfspace/rfspace_source_c.h +++ b/lib/rfspace/rfspace_source_c.h @@ -145,6 +145,8 @@ private: /* members */ size_t _nchan; double _sample_rate; double _bandwidth; + double _center_freq; + double _freq_corr; gr::thread::thread _thread; bool _run_usb_read_task; -- 2.25.1