Raspberry Pi Audio Hats

Hey folks. Today is the day, when I close the task that I was trying to solve for 3 years, with many many attempts. Finally, together with my friend Claude, we managed to do it.

It is 2.1 configuration with two TAS5805M DACs daisy-chained working on Linux the way it should - Single sound card, two codecs, driven by two kernel module instances, **individually controlled** via Alsa. 

Main DAC driver stereo speakers, with 15-band EQ available. Secondary DAC drives a single subwoofer channel in bridge mode, with frequency adjustable LF filter.  Seriously, I was fighting kernel module and device tree for 3 YEARS to make it work the way it should!

The code and docs are here. Next stop is TAS5825M version of the Louder Raspberry Hat, with dual-DAC variant from the start.

Hey Folks. I spent the last 2 weeks trying to upgrade my TAS5805m raspberry driver to support multiple DACs chained into a single audio interface. Specifically for my 2X Hat (on the pic). Seems like driver implementation is almost ready for it, but I struggled to provide a valid device tree file that would configure a single audio interface that is linked to multiple DACs. I reached out to TI support, and they provided a whole new driver implementation, that is a work-in-progress on their side.

After looking inside the code, I found it to be a bit clumsy, and many features were missing compared to the original implementation. But in other aspects, the TI code was much better integrated into the Linux kernel ASoC, and most importantly, after some changes, it worked with dual DAC implementation. At this point, I will provide this implementation as an alternative to the original driver until I figure out how to make it work in the chaining config (branch)

It works with both Louder Raspberry 1X and 2X hats, and for both, I've implemented 11 profiles for all configurations: 0.1 (subwoofer, bridged) / 2.0 (stereo) / 2.1 configs

• 0: 60Hz cutoff low-pass / 60Hz cutoff high-pass / 60Hz crossover
• 1: 70Hz cutoff low-pass / 70Hz cutoff high-pass / 70Hz crossover
• 2: 80Hz cutoff low-pass / 80Hz cutoff high-pass / 80Hz crossover
• ...
• 9: 150Hz cutoff low-pass / 150Hz cutoff high-pass / 150Hz crossover
• 10: Flat response / Flat response / No crossover

I'm testing it myself currently and it sounds great, although it is a challenge for such a small hat to dissipate all the heat from two DACs. The 2X Hat itself is available for purchase now, and it is also possible to stack two 1X Hats to get a similar result.

Next stop is to do 2.1 for the larger Media Center format, and also ship the same DAC setup into the ESP32 device.

Hey folks. I'm finalizing a major update in the Raspberry Hat family. I've straighten out the full lineup of DACs that I have developed and tested and all of them are available right now in a cost-efficient Hat shape (Media Center versions are coming up next). All of them available in 1X version, which is a simple stereo DAC; and a 2X version that is a Dual configuration that is possible to use on new Raspberry Pi 5 with both outputs available independently (so you can create multi-zone systems using a singe host device).

First in the line is HiFi Rasberry Pi Hat based on well known PCM5100 DAC

The next one is Loud Raspberry Pi Hat based on MAX98357A DAC (5W per channel with 5V at input)

Amped Raspberry Pi Hat is a PCM5100 DAC combined together with TPA3110 D-class amp. It is very easy to setup and it can drive large speakers, delivering up to 25W per channel (or about twice as much in bridge mode)

An the last one is well known Louder Raspberry Hat based on TAS5805M DAC, with around the same 25W per channel, but now with 2X version with a companion DACs connected together to drive 2.1 speaker set

This feels as a major achievement for me and I hope that anyone who's out there to do an audio on Raspberry will find something useful for themselves.