Feedback on custom audio board,

[otemrellik]

Hey all, I'm looking to make my own custom audio board for a new project I'm working on. This is a test version that I intend to use on a breadboard. I pretty much just followed the schematic from the Rev D version, removing all that I didn't need (SD/memory). Just wanted to make sure I'm not missing anything obvious or doing something totally wrong. I'm still very new to PCB design. Anywho, here is the schematic and a link to the easyeda project.

myTeensyAudioBoard - EasyEDA open source hardware lab

In EasyEDA open source hardware lab, open source square pools all kinds of electrical design engineerings together to realize resource sharing easily.

oshwlab.com

Any input is greatly appreciated.

 

[TomChiron]

From a quick look everything looks OK (no guarantee).

It could be helpful to check the datasheet and see which capacitors have what function. This is important to place them on the pcb. E.g. there is one 0.1µF for VDDIO which should be placed as near as possible to that pin of the chip. In this schematic this is not clear for all caps. When I looked into it at least I was confused and not sure which cap is where.

Keep in mind that the behaviour regarding any noise or ground loops can be different in the version on your breadboard. On a pcb you have other routings and lenghts of the connections (+ possibly a ground plane).
Cable length for the higher freqency signals can be also problematic if it gets too long. Especially for MCLK. Such signal can also induce noise to the I2C bus in a way to disturb and stop the functioning if the cables get too close.
I am not sure how reliable such testing can be.

Curious: How do you plan to test it on a breadboard? Do you put just the chip on a small adapter pcb and add everything else on the breadboard?

 

[otemrellik]

Thanks for the feedback! Looks like I didn't place the 0.1uF cap close to the chip at all. I just moved things around a bit this morning. I fully expect to have a lot of noise on the breadboard. I already have most of the prototype on a breadboard using the normal audio board and it's a bit noisey. It's placed behind the teensy just so I can more easily access the pins.

My custom board will hopefully just pop right into place where the normal audio board is now. This custom board is pretty much just a test to see if I can recreate the audio board on my own. The final version will be on a much larger pcb with a bunch of other components and whatnot.