AnsweredAssumed Answered

how can i use delay and sum beamforming algorithm between two microphone  pcm data?

Question asked by Jaiswal.vinod on Feb 21, 2017
Latest reply on Feb 21, 2017 by Oliver Beirne

Hi all,


1. I have two question before developing my delay and sum beamforming algorithm.

A). I am working on Stm32 STM32F401RE NUCLEO with X-NUCLEO-CCA02M1 on Stm32 OsxAcosticBF stack in this source code they are collecting microphone PDM data in to this" I2S_InternalBuffer"

''uint16_t * DataTempI2S = &(I2S_InternalBuffer[X_NUCLEO_CCA02M1_Handler.PdmBufferSize/2]);
uint8_t a,b=0;
for(index=0; index<X_NUCLEO_CCA02M1_Handler.PdmBufferSize/2; index++) {
a = ((uint8_t *)(DataTempI2S))[(index*2)];
b = ((uint8_t *)(DataTempI2S))[(index*2)+1];
((uint8_t *)(X_NUCLEO_CCA02M1_Handler.PDM_Data))[(index*2)] = Channel_Demux[a & CHANNEL_DEMUX_MASK] | Channel_Demux[b & CHANNEL_DEMUX_MASK] << 4;;
((uint8_t *)(X_NUCLEO_CCA02M1_Handler.PDM_Data))[(index*2)+1] = Channel_Demux[(a>>1) & CHANNEL_DEMUX_MASK] |Channel_Demux[(b>>1) & CHANNEL_DEMUX_MASK] << 4;''


 after demuxing R/L data they are passed that data into PDM library which is  convert  R/L data(PDM format ) into PCM format.

here i want to know- that  PCM data they are collecting into any buffer or directly  they are passed into OsxAcosticBF algorithm library .


B.) how can i use delay between two microphone after getting PCM data because that data in digital format?