Question about rtlsdr read_sync()

This is merely a historical archive of years 2008-2021, before the migration to mailman3.

A maintained and still updated list archive can be found at

Allen Welkie allen.welkie at
Mon Nov 24 02:20:05 UTC 2014

Just trying to figure out how to use the rtlsdr_read_sync() function, and
I'm not understanding just by reading the source. Am I supposed to call
this function continuously in a loop in a thread separate from the sample
processing, or can I do some processing in between calls to
rtlsdr_read_sync()? In other words, are the samples being buffered on the
rtlsdr device in between calls? If so, what's the size of that buffer?

Also, what functions need to be called before I can use the read_sync or
read_async functions? I'm calling rtlsdr_open, rtlsdr_set_center_freq, and
rtlsdr_set_sample_rate before calling rtlsdr_read_sync, but I'm not getting
any samples (and subsequent calls to rtlsdr_read_sync or read_async fail,
e.g. from running the rtlsdr_fm program).

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the osmocom-sdr mailing list