Multy PDM microphones and audio reference signal sample synchronously

Robotics & Edge Computing Jetson Systems Jetson Orin NX
1

Does Orin NX supports sampling 6x PDM microphones and 2x reference signals synchronously? which used to run the beam-forming and AEC algorithm.
How can I config to sample the 8 channel signals above synchronously?

3

Hi,

I have couple of questions to understand your requirements better in order to provide a suggestion

  1. Do you have any block diagram or schematic info on how you would like to realize this connections. This would help us to understand your usecase better.
  2. Orin Nx supports I2S as audio IO interfaces (for PDM direct interface, we actually required APE DMIC which are not exposed on Orin NX board) , are you trying to use the I2S interface connected to the external Mics?
4

Thank u for reply.
I’m sorry that I couldn’t send block diagram or schematic, for my project is confidential.
I have found the Orin NX board only support 2 IISs for Audio devices, so I purpose to sample the 6 x microphones and 2 x reference signals by IIS0 in TDM mode.
How many channels does IIS0 TDM mode support? In other case, there many need 8 x microphones and 4 x reference, 12 audio channels need.
Merry Christmas!

5

I understand, Orin NX I2S supports upto 16 channels per instance in TDM mode. Does a single I2S instance sufficient for your design?.

6

For the Orin NX board only leads out 2 IIS port, I want to use IIS0 to sample the microphone and reference signals in TDM mode, when the IIS1 port used to connect 1 or 2 audio PA.
As your reply, may I use the IIS0 port to sample 8 microphones and 2 or 4 reference signals synchronously
, which sampled by cascaded multi-channel codecs in TDM mode?

7

yes, as your max audio channels are 12, it is possible to use single I2S for this, provided the external codec muxes your 8 mic and 4 reference signals to form a single TDM I2S signal