I’m planning on attempting to build something with INMP441 mics and wondered if the Duo SDK already has native support for it. Looking through the community I’ve only seen people talking about how it’s possible but no detailed guide of sorts.
Thanks in advance 
OK, the INMP441 is a digital mic w/ I2S formatted output. It is possible to do I2S input with the Duo, but it’s not “native” in that raw I2S support isn’t enabled by default and you have to tweak the SDK source code and rebuild the kernel & system image in order to enable it. Note also that the I2S I/O port on the Duo runs at 1.8V, so you’ll have to power your INMP441 with 1.8V or risk damaging the Duo’s SoC. Additionally, I2S uses the same pins as the Ethernet interface, so you can’t do both at the same time.
This thread has some detail on how to enable I2S input: MilkV Duo external I2S input