Hi,

My team and I just bought the RPi Zero 2W and 4 INMP441 MEMS mics. It's capable of I2S interfacing, but apparently, it turns out that we can't directly connect the mics to any open GPIO pins.

We require this number of mics for a real-time localisation project we're working on.

Hope for any kind of help, preferably lowest cost. We're ready to work with both programming/hardware solutions. Would appreciate it if anyone could pitch in and provide some guidance!

themellowhost wrote: My team and I just bought the RPi Zero 2W and 4 INMP441 MEMS mics. It's capable of I2S interfacing, but apparently, it turns out that we can't directly connect the mics to any open GPIO pins.

Yes, thats true. All Pis prior to Pi5/CM5 only have a single I2S port, so you only can connect two microphones.

Pi5/CM5 has I2S width 4 channels. There you can connect up to 8 of these microphones. Been there, done it.

See
https://learn.adafruit.com/adafruit-i2s ... iring-test

For the first pair use GPIO 20, for the second pair use GPIO 22 instead, for the third GPIO 24, for the forth GPIO 26.

You need to adapt the dts in order to use the extra channels.

Or perhaps use two Zeros? Probably cheaper than a single Pi5.

Software guy, working in the applications team.

jamesh wrote: ↑

Wed Nov 12, 2025 10:15 am

Or perhaps use two Zeros? Probably cheaper than a single Pi5.

Or a Pico (using PIOs to interface to the mics) and a Zero. Even cheaper.

Or even ditch the Zero and use a Pico2W :D

Always interested in innovative audio startups needing help and investment. Look for InPoSe Ltd or Future Horizons on LinkedIn to find me (same avatar photograph)

jamesh wrote: ↑

Wed Nov 12, 2025 10:15 am

Or perhaps use two Zeros? Probably cheaper than a single Pi5.

Won't work. For audio location you need a cycle-precision synchronisation between all microphones.
Ok, you could get away with I2S master on one and I2S slave on the other board, but then you need a low latency communication path for the auto data from the slave board to the master.

Not worth the trouble.