I would like to create a synth module (for eurorack format) using a Teensy 3.6 and I have a couple of question to share (since I am pretty noob).

The module is inspired by the magnificent Ornament & Crime and it will have these features:

  • 4 digital inputs (sampled at low frequency)
  • 4 analog inputs sampled at 96KHz@24bit
  • 4 analog outputs 48KHz@24bit
  • OLED color display 128x128 (16 bit)

I was thinking to use:
  • Teensy 3.6
  • OLED display with SSD1351
  • Audio codec I2C or SPI with 4 ADC and 4 DAC (for digital inputs I would use four digital input from Teensy)

I have some questions about this setup:
  1. Which audio codec do you suggest? I prefer to use one that it is well supported. In case I could also use ADC and DAC separated. I2C or SPI?
  2. Can use 2 DMA channel for two different SPI channels or SPI + I2C channel? I would use one SPI or I2C channel for audio codec and one SPI channel for OLED.
  3. Making some calculation I will need about 30MByte/s of band width (audio input: 4*96K*32bit , audio output: 4*48k*32bit and for the OLED: 160*160*16bit*30fps). Is that too much for the Teensy SPI and DMA?
  4. In case I will use an I2C audio codec, I would need 18MByte/s of band width, is this feasible for a the Teensy I2C?
  5. I chose a display with SDD1351 since I read that it is pretty well supported, but I don't know if there any better option.

Thank you for your patience.