Arduino Mega vs Teensy3.1

Would the arduino mega work with the teensy audio shield?
I don't want to stop using teensy but sadly I see many problems
1. I'm almost completely unable to read/ define pins
2. I need more pins

Hi,
easy answer: no chance.

But tell us about your problems with the pins, and about your project.
Maybe we can help you.

I haven't tried the Teensy Audio Board myself yet, nor looked at the code-- Thus I imagine there would be any number of port level elements (at minimum) that would need to be rewritten. However I believe the extension board itself does run off the I2S protocol-- In which case if you are really 'married' to the Mega form factor, the Arduino Due is almost the same form factor and there is a library to enable I2S output.

Of course you would still need to purchase the Teensy audio board as that is where the codec chip is.

The Teensy Audio Board requires I2S master mode. Teensy generates MCLK, BCLK and LRCLK, so those 3 signals are inputs on the audio board.

I'm pretty sure Arduino Due isn't up to the task of master-mode I2S. From the ArduinoDueHiFi readme:

The driver currently supports slave mode only as the ARM doesn't appear to be able to generate the appropriate MCLK signal to drive external converters.

Click to expand...

That library also appears to be designed to require an interrupt for each individual sample, which means it can only tolerate 1 sample interrupt latency until the audio glitches. Arduino Due has DMA, but that code doesn't seem to make any use of it. Of course, it also doesn't have a large collection of interoperable audio processing objects! There is at least a fixed frequency sine wave example.

At the very least, for regular Arduino boards you'd need something like the Open Music Labs Codec Shield, which uses I2S slave mode. If you give that a try, I'm pretty sure you'll find it's software support isn't nearly as good as what you get with Teensy.

:> Not trying to disagree with Paul/Teensy, just perhaps be (naively!) helpful. *Stands quite corrected*