Dual-Daisy-DSP

Inter-daisy Digital Audio

A pair of programs demonstrating a multi-daisy setup sharing digital audio over I2S using the SAI peripherals.

The demo is made of two programs:

DaisyA

This program configures SAI2 as the "Leader" (SAI2 B in Sync::MASTER).

A pair of waveforms are generated in the audio callback, and transmitted over the SAI2 buffers to DaisyB. The data received back from DaisyB is written to SAI1, outputting them on the seed's analog outputs.

DaisyB

This program configures SAI2 as the "Follower" (SAI2 B in Sync::SLAVE).

Audio is received on SAI2 from DaisyA, and copied to SAI1 to output on the analog outputs. The same audio is echoed back over SAI2 to DaisyA.

Build

Clone the repo

Clone the repo with submodules:

git clone https://github.com/stephenhensley/Dual-Daisy-DSP --recurse-submodules

or, initialize the submodules after cloning:

git clone https://github.com/stephenhensley/Dual-Daisy-DSP
cd Dual-Daisy-DSP
git submodule update --init

Build the libraries

Build the libraries with the convenience script:

./ci/build_libs.sh

or manually build them by running make in each library directory.

Compile the programs

In each DaisyA and DaisyB simply run: make

Flashing the programs

From each project dir, run make program-dfu with only the Daisy you'd like to flash in the system bootloader.

Alternatively, you can use the web programmer. The binary files are created in the build/ dir of each project directory.

Minimal Hardware Requirements and Connections

To try out this demo you'll need:

• 2x Daisy Seed (any revision)
• several jumper wires (>=9)
• a breadboard (not actually required, but ... helpful)
• an o-scope, or audio jack for monitoring the output

1. Flash each daisy with the respective programs
2. Connect all four GND pins to each other
3. Wire each of the following pins to the same pin on each Daisy:
   • D25 (SAI2 SB)
   • D26 (SAI2 SA)
   • D27 (SAI2 FS)
   • D28 (SAI2 SCK)
4. Plug each Daisy into USB power

When funcitoning properly:

• DaisyA should be blinking twice a second
• DaisyB should be blinking four times a second
• DaisyA and DaisyB audio out 1 should be a 220Hz waveform
• DaisyA and DaisyB audio out 2 should be a 440Hz waveform