Multichannel Equalizer (8 channels) with Teensy?

[megrania]

Hi,

I'm new to the world of the Teensy board and I'm looking for some guidance here.

I want to build an 8-channel equalizer, and I wonder if that would be possible with one or two Teensy boards.

The idea is to have 8 line inputs and 8 line outputs, and be able to equalize each channel individually. I'm not as much worried about the
software side as I have plenty of experience with writing DSP code, but I need some advice on the hardware side.

I've read that it's fairly straightforward to stack two audio shields to get 4-channel I/O, but I can't really find any details.

Does anyone have a hint for me ?

Best,
N

 

[PaulStoffregen]

On the audio shield page, scroll down until you see this picture.

Sparkfun wrote a great tutorial for quad channel on Teensy 3.2.

https://www.sparkfun.com/news/2055

The process is basically the same for Teensy 4.0. You'll configure the 2nd audio shield to use the alternate I2C address, and then cut the 2 data signals so they don't connect to the normal data pins, and solder wires to connect them to the other data pins used for channels 3 & 4. Refer to the design tool docs for the pin numbers.

One small gotcha is Rev D2. If you have a D2 version audio shield, it can only be used for channels 1 & 2. You need Rev D (not "2") for the one that becomes channels 3 & 4. Fortunately we're past the 2022 chip shortages and today all audio shields are again Rev D.

 

[megrania]

Hmm that sounds fairly doable, with two of these I could run an 8-channel setup (assuming the latency is the same on both) ... thanks for the quick answer !