Hail, I am introducing myself to SDR technology and gnuradio through whatever project documentation I find, dissecting the code and executing simple experimental flow graphs to test understanding of concepts, hoping to avoid forum queries (this is my first). Although the audio sink is not critical to my ultimate use of gnuradio and a bit of a diversion I will eventually start digging into it. However, I thought to submit a query on whether there is something obvious I should try in order to get it working. I am using gnu radio companion 3.8.1.0 (Python 3.6.10) and feeding the audio sink with a 1 kHz tone from the signal source block.
(1) staring with: :~> aplay -L null Discard all samples (playback) or generate zero samples (capture) default Default ALSA Output (currently PulseAudio Sound Server) sysdefault:CARD=PCH HDA Intel PCH, ALC892 Analog Default Audio Device front:CARD=PCH,DEV=0 HDA Intel PCH, ALC892 Analog Front speakers surround21:CARD=PCH,DEV=0 HDA Intel PCH, ALC892 Analog 2.1 Surround output to Front and Subwoofer speakers (...) hdmi:CARD=PCH,DEV=0 HDA Intel PCH, HDMI 0 HDMI Audio Output hdmi:CARD=PCH,DEV=1 HDA Intel PCH, HDMI 1 HDMI Audio Output hdmi:CARD=PCH,DEV=2 HDA Intel PCH, HDMI 2 HDMI Audio Output hdmi:CARD=PCH,DEV=3 HDA Intel PCH, HDMI 3 HDMI Audio Output hdmi:CARD=PCH,DEV=4 HDA Intel PCH, HDMI 4 HDMI Audio Output (2) using sysdefault:CARD=PCH for the audio sink device name, both 44.1 kS/s and 48 kS/s the following runtime error results: (3) gr::log :INFO: audio source - Audio sink arch: oss audio_oss_sink: sysdefault:CARD=PCH: No such file or directory Traceback (most recent call last): File "/gnuradio/examples/audiotest.py", line 136, in <module> main() File "/gnuradio/examples/audiotest.py", line 112, in main tb = top_block_cls() File "/gnuradio/examples/audiotest.py", line 78, in __init__ self.audio_sink_0 = audio.sink(samp_rate, 'sysdefault:CARD=PCH', True) File "/usr/local/lib64/python3.6/site-packages/gnuradio/audio/audio_swig.py", line 220, in make return _audio_swig.sink_make(*args, **kwargs) RuntimeError: audio_oss_sink >>> Done (return code 1) (4) Fixing this isn't critical and in time I will get to the bottom of it; the forum query just removes the possibility of an obvious answer that most everyone else knows about. My guess is that I have to disable the Pulse audio server. Rick