#embeddedaudio

TLV320DAC3100 take 2 🎧🔊

After much wrasslin’ with the TLV320DAC3100, we finally have a library that properly configures the PLL and sets up both the headphone and speaker output well enough. However, we made a mistake with the headphone wiring, accidentally swapping ground and mic, and we’re experiencing some noise in the headphones when the Class D speaker output is active.

We’re rerouting the board to separate the speaker outputs from the TRRS jack to address this. While at it, we’re also exposing the MICDET and bias pins—interestingly, the mic detects can double as a potentiometer input for volume control. The board grew by 50 mils, but we believe this version is the one. After testing, it should be ready for sale.

PCM5102 and PCM5100 I2S DAC breakouts 🔊🎶

We're starting to stock a lot of chips that can do digital I2S out, which makes for great-quality audio playback. That's great when you have enough processing power to decode WAVs or MP3s in real-time. However, we could really use some better DACs in the shop. We like the UDA1334A (https://www.adafruit.com/product/3678), but that's technically discontinued - it's great because it doesn't require an MCLK that some boards like the Raspberry Pi don't have and doesn't need I2C configuration either.

PCM1840 Quad Input Microphone I2S ADC with Hardware Pin Configuration 🔊🎤🛠️

We looked up this chip in 2021, right before we got smacked with a chip shortage and couldn't get any to prototype with - but we're back in biz and respinning a prototype up. While looking up the TLV320ADC quad microphone I2S ADC, we also bumped into the PCM1840. These chips are similar (almost identical pinout) but have analog-only inputs and no I2C or SPI configuration. Yep, it's completely hardware pin bootstrapped, which makes setup much easier because you can use any I2S driver. It can act as an I2S controller (it clocks all I2S pins out) or the I2S peripheral (I2S clocks input and data is output). We whipped together a breakout to figure out how to get TDM I2S input working without dealing with the I2C setup. Looks awesome for spatial audio algorithms and voice recognition projects. You can pick up the PCM1840 ADC on DigiKey - lots are in stock!