On 25/06/2014 15:16, Michael Howard wrote:
On 25/06/2014 00:49, Sinan Akman wrote:
Hi Mike
I have tried a second receiver and the results are the same, as in, the wandboard fails, the cubietruck works. I fear that this a design issue and I'm wasting your time.
There is one another thing. When you run aplay for testing I suggest you define the format and the rate explicitly and don't use plugin as part of your device. It is possible that your default format that your aplay on wandbord picks is not compatible with what your receiver can handle.
Regards
Sinan Akman
Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Hi Sinan,
Well I've tried all the formats and various rates without suceess.
I've determined the capabilities of the Wandboard spdif to be;
alsacap -d hw:0,0 *** Exploring configuration space of device `hw:0,0' for playback *** 2 channels Sampling rate 32000..48000 Hz Sample formats: S16_LE, S24_LE
as opposed to the Cubietruck (which works - as does Win7);
alsacap -d hw:1,0 *** Exploring configuration space of device `hw:1,0' for playback *** 1..2 channels Sampling rate 8000..192000 Hz Sample formats: S16_LE Significant bits: 16
The ouputs of speaker test are almost identical;
Wnadboard;
speaker-test -Dsysdefault:CARD=imxspdif -c2
speaker-test 1.0.25
Playback device is sysdefault:CARD=imxspdif Stream parameters are 48000Hz, S16_LE, 2 channels Using 16 octaves of pink noise Rate set to 48000Hz (requested 48000Hz) Buffer size range from 64 to 16384 Period size range from 32 to 8192 Using max buffer size 16384 Periods = 4 was set period_size = 4096 was set buffer_size = 16384
Cubietruck;
speaker-test -Dsysdefault:CARD=sunxisndspdif -c2
speaker-test 1.0.25
Playback device is sysdefault:CARD=sunxisndspdif Stream parameters are 48000Hz, S16_LE, 2 channels Using 16 octaves of pink noise Rate set to 48000Hz (requested 48000Hz) Buffer size range from 4096 to 32768 Period size range from 1024 to 8192 Using max buffer size 32768 Periods = 4 was set period_size = 8192 was set buffer_size = 32768
One obvious difference is that the Wandboard uses 'snd-soc-dummy-dai'.
I'll get a scope on the job this evening, is there anything inparticular I should be looking for?
Cheers, Mike.
I've used a scope on both the CT & WB but it didn't shed any light on the matter. Voltages are as advertised (which maybe the problem) and there is very little difference between the frequencies of the two boards or how the wave looks. Frequencies are approx 1.78MHz for the Cubietruck and approx 1.8MHz for the wandboard.
The volatges match the spec sheets, i.e. 5v for the Cubietruck and 3.3v for the Wandboard at VCC whether audio is playing or not.
So unless both my receivers have a problem with only 3.3v I'm at a loss. I can't find anything on the limited specs for the receivers relating to this.
I guess I'll just sideline the Wandboards and use proper kit instead. I can still compile on them, until they overheat :)
Cheers, Mike.