Teensy 4.0 Sound from Electret Bob to FFT

[MSO]

Hello! I just purchased the 4.0 and I was looking to do some FFT on live audio. I currently have a microphone that produces a 1.25V biased 2V peak to peak signal which I have been using with a MSGEQ7 and Teensy 2.0++. I would like to cut out the temperamental middleman and do it in software.

I understand that the ADC is still being worked on, but I wanted to ask if there are any alternatives for a mic BOB or if I would be best just waiting until an ADC appears? Thanks for any help you can provide!

[Frank B]

I'd use the Audio Shield.

[MSO]

A good suggestion, I'm hoping to avoid additional hardware, so waiting looks like the best option for the time being. Thanks for your help.

[DD4WH]

Another option would be to use an I2S microphone breakout board.

The ICS43434 delivers excellent audio results if you care about a little filtering of the 3.3V supply.

https://www.tindie.com/products/oneh...al-microphone/

https://forum.pjrc.com/threads/52175...l=1#post183337

[MSO]

That looks like a great option. I don't need it to be a particularly clean signal, but it still seems like it does what I need. Thanks for your help!

[palmerr]

An additional option is to use MEMS microphones which often communicate directly via I2S or SPI.

There's a good description in this document https://www.st.com/content/ccc/resou...DM00187403.pdf about the options.

This thread looks at some of the practicalities of MEMS for Teensys. https://forum.pjrc.com/threads/57697...light=mems+i2s

And this one looks at using multiple MEMS microphones https://forum.pjrc.com/threads/58937...light=mems+spi

Have fun!

[MSO]

More great information! Thank you. I thought i2s was a higher level system, but it looks like little i2s BOBs may be just as good as the analog one I have.