I thought it would be really cool to make a music tuner this week. Did I get around to that? No, but at least I got around to "measuring sound" with a board. I based my board off Neil's I2S board, though I used a SAMD21 (Anthony also advised that it would be a good time to "graduate" from the D11C) and it took a lot of time to solder (luckily, I got to use a really nice soldering iron belong to the MIT Radio Society for this, so I was able to handle the many tiny pins). I was somewhat nervous about using a different microcontroller since I could really be sure that I was making a correct translation between the D21E and ATTiny1614), but I was assured that there were really only three pins to really pay attention to with respect to I2S: the clock (SCK), the data (SD), and power and ground. This really reminded me of I2C, though despite the naming and similar structure Anthony assured me the two (I2S and I2C) are not related otherwise (alas, naming complications--almost like Java and JavaScript).
After taking a long time to solder the board, I realized I was running out of time, so I borrowed/adapted Neil's code for the I2C mic (adapting only the pins and even using the Python interface).