custom audio card on beaglebone
From: crazyiop at gmail.com <hidden>
Date: 2017-01-25 10:30:30
Hi Anish, thanks for giving me some thougt. Here is what I found: On Sun, Jan 22, 2017 at 03:47:54PM -0800, anish singh wrote:
On Sun, Jan 22, 2017 at 1:38 PM, jo [off-list ref] wrote:quoted
root at beaglebone:~# aplay -v Pom\ Pom.wav Playing WAVE 'Pom Pom.wav' : Signed 32 bit Little Endian, Rate 44100 Hz, Stereo ALSA <-> PulseAudio PCM I/O Plugin Its setup is: stream : PLAYBACK access : RW_INTERLEAVED format : S32_LE subformat : STD channels : 2 rate : 44100 exact rate : 44100 (44100/1) msbits : 32 buffer_size : 22050 period_size : 5512 period_time : 125000 tstamp_mode : NONE period_step : 1 avail_min : 5512 period_event : 0 start_threshold : 22050 stop_threshold : 22050 silence_threshold: 0 silence_size : 0 boundary : 1445068800 #nothing play and the above stay displayed -as is- until I ctrl-cPossible that you have not turned on the mixer controls i.e. enabling the volume? Check sw_ptr and hw_ptr and see if those are increasing or not? Probe the I2S lines and see if there is any data?
So first, the above command in fact do finish after the length of the file (I thought I took a much smaller test sample..) The mixer control were all on and volume to the max. I don't have a scope, but you made me realize that I'm clueless in front of my problem without one... So I finnaly found an access to one. The measure show that the input clock of the pll (mclk) is just non-existant. I now know what to look for. I tried to find a reference to those sw_ptr and hw_ptr somewhere, without success, what are they and where can I find/probe them ? Thanks!! Jonathan.