8xMicrophones on 4x1-bit ports possible?

Discussions about USB Audio on XMOS devices
New User
Posts: 2
Joined: Wed May 17, 2023 9:50 am

8xMicrophones on 4x1-bit ports possible?

Post by CORE »

We are currently working on a project where we want to utilize the microphone array library to simultaneously read data from eight microphones. However, we suspect that there might have been an error in our PCB design. Instead of connecting all the PDM data channels to a single 8-bit port as recommended by the microphone array library, we inadvertently connected them to four separate 1-bit ports. Furthermore, we paired two microphones (left and right) together on one of these 1-bit ports.

Considering this deviation from the recommended configuration, we are wondering if it is still possible to successfully read out the data from the microphones using multiple 1-bit ports.

We would greatly appreciate any insights or advice you can provide. Thank you in advance for your responses.
User avatar
XCore Expert
Posts: 1004
Joined: Thu Dec 10, 2009 9:20 pm
Location: Bristol, UK

Post by Ross »

Are the mic pairs writing on both edges i.e. like DDR? The current range of xcore devices are not capable of doing this in the port hardware unfortunately (spoiler alert, this might come later..).

I should imagine you could modify the lib_mic_array code to handle 4 mics on the 1-bit ports though.
Technical Director @ XMOS. Opinions expressed are my own.