Arduino MKR ZERO (I2S bus & SD for sound, music & digital audio data)

A great description and general information about the SAMD21 one could find here: SpartkFun SAMD21 Overview

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First one has to install the Arduino SAMD boards. In tools/boardmanager search and install the
Arduino SAMD Boards.

Secondly we need the specific Zero libraries. In sketch/library manager search and install the
Audiozero Library and the
SD Library (by Sparkfun).

AudioZero-1.1.1.zip

Arduino SD library by Sparkfun
or
Arduino SD Library by Adafruit

On Arch Linux it needs more than one attempt to upload the code, the /dev/ttyACM0 can't be opened: No device found on ttyACM0!

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In open/libraries/ArduinZero one finds the SimpleAudioPlayerZero example.
These commands are needed:

 SD.begin(28);   //Initializes the SD library and card
 AudioZero.begin(2*44100);   //Initializes the DAC, 44100kHz stereo => 88200 sample rate
 File myFile = SD.open("test.wav");   // open the wave file
 AudioZero.play(myFile);   //plays the file

Simple audio player
The quality of the WAV file needs to be 44100kHz stereo and decoded with 8-bit unsigned PCM.
The audio signal is on pin DAC0/A0.

Some bugs are in the original code!
- one needs a short delay after Serial.begin
- the SD-card pin is 28

here is the fixed code:
SimpleAudioPlayerZero_Fixed

Unfortunately there is quite some bad humming after playing a file.

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The MKR ZERO board need around half a second after initializing the serial port, so one has to pause the board before using any serial command.

Serial.begin(115200);
delay(500);

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pinout digram by Arduino.cc

The onboard LED is on pin 32. One could use LED_BUILTIN instead.

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4 PWM pins
they can be changed from default 8-bit to 12-bit resolution.

1 Digital-to-Analog Converter
10-bit (1024 values) by default, setting the resolution to 12 bits, one can use values between 0 and 4095 for analogWrite().

 analogWriteResolution(bits);
 analogWrite(pin,value);

video from ForceTronics - Arduino Zero DAC Overview and Waveform Generator Example

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Use a Li-Po battery bigger than 700mAh

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Connector: SHR-05V-S-B
It just provides 5V power!

To connect Adafruit's STEMMA boards or Sparkfun Qwiic boards (!if the run on 5V!) one needs an adapter like that one:
JST SH connector 5-pin (Arduino MKR) to 4-pin (STEMMA QT / Qwiic Cable)

More information one can find in Ben Everard article “Qwiic, STEMMA QT, and Grove” HackSpace (Issue 38, 2020, p72)

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Adapting Sketches to M0 & M4 by Lady Ada

Your Arduino SAMD21 ADC is wrong: did you notice? - omzlo.com

Arduino Web USB

ATSAMD21g18 Bootloader With J-link Debugger - instructable.com

Sam 15x15 - avdweb.nl

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This manuals is made by Wolfgang Spahn 2020.
Except where otherwise noted, content on this wiki is licensed under the following license: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

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