Hello everyone,
I'm working on porting the PCMD3140IRTER codec to the Kirkstone BSP on an STM32MP13 platform. At the moment, I have connected only two microphones (presumably the left and right ones) to the PDMDIN1_GPI1 line.
The microphones are Adafruit PDM MEMS, based on the MP34DTx chip. I verified their behavior using an oscilloscope, and the signals look correct according to the datasheet. So far, everything seems fine.
The issue arises when I try to record audio using the following command:
arecord -D hw:0,0 -f S16_LE -r 48000 -c 2 test.wav
When I listen to the recorded file, I can hear only the left channel, as if the right microphone is not being captured. If I change the ti,pdm-edge-select property from:
<0 1 0 1>
to
<1 0 1 0>
I still hear only the left channel, but it now seems to come from the other microphone. So, it looks like only one microphone at a time is being used, and it's always recorded as the left channel, regardless of the pdm-edge-select setting.
Additionally, if I disable CH1_ASI_EN and enable only CH2_ASI_EN, nothing gets recorded in either pdm-edge-select configuration. In Audacity, the right channel is completely silent.
My impression is that only one channel is actually being used, instead of both, as expected for stereo input from two microphones.
