ReSpeaker 4-Mic Linear Array Kit Channel Position Problem.

Hi,



I am using raspberry pi3 b & b+ and 2018-04-18-raspbian-stretch.

I bought ReSpeaker 4-Mic Linear Array Kit for Raspberry Pi.



#Doing capture && playback the same time

arecord -D hw:1,0 -f S32_LE -r 16000 -c 8 to_be_record.wav &

#mono_to_play.wav is a mono channel wave file to play

aplay -D plughw:1,0 -r 16000 mono_to_play.wav



The position of each channel changes(to_be_record.wav).

I think it appears every time an overrun occurs.



I need your help.



thanks.

Hi there,



We see this issue/bug before. thanks.



Note: Limit for developer using 6-Mics Circular Array Kit(or 4-Mics Linear Array Kit) doing capture & playback the same time:



capture must be start first, or else the capture channels will possibly be disorder.

playback output channels must fill with 8 same channels data or 4 same stereo channels data, or else the speaker or headphone will output nothing possibly.




best rgds

Bill

Hi, Bill



3. If you want to play and record at the same time, the aplay music file must be mono, or you can not use this command to play.



I obviously started the capture first, and played the mono file…



thanks.

Hi there,



I checked with software engineer, we suspect the SD card speed related issue. it shall run on class10 or higher speed sd card. What is your sd card speed? thanks.



best rgds

Bill

Hi Bill



I am using a class 10 speed of 48MB/s.

(<LINK_TEXT text=“https://www.ebay.com/itm/SanDisk-Ultra- … SwvApaJQM0”>https://www.ebay.com/itm/SanDisk-Ultra-8GB-Class-10-TF-48MB-S-Flash-SD-HC-Memory-Card-Mobile-Phone-Tablet/311869820496?epid=9010799638&hash=item489ce3ce50:g:GokAAOSwvApaJQM0</LINK_TEXT>)



Do you have a sd card to recommend?



thanks.

Hi there,



The SD shall be OK. do you mind providing the screen logs includes all commands and outputs? we can simulate it. thanks.



best rgds

Bill

Hi Bill



Is this what you want?



I just proceeded as follows.

#Doing capture && playback the same time

arecord -D hw:1,0 -f S32_LE -r 16000 -c 8 to_be_record.wav &

#mono_to_play.wav is a mono channel wave file to play

aplay -D plughw:1,0 -r 16000 mono_to_play.wav



thanks,
command.png

Hi, Bill



I have additional questions.



Should I use the s32_le format?

could I use s16_le format?



thanks,

Hi there



we use s32_le in test. thanks.



Bill

Hi



Is there a special reason to use it?



thanks