#include <SPI.h>
#include "wiring_private.h" // pinPeripheral() function

// DOCUMENTACIÓN AQUI:
// https://learn.adafruit.com/using-atsamd21-sercom-to-add-more-spi-i2c-serial-ports?view=all
// SPIClass SPI (&PERIPH_SPI,  PIN_SPI_MISO,  PIN_SPI_SCK,  PIN_SPI_MOSI,  PAD_SPI_TX,  PAD_SPI_RX);

// SPI_PAD_0_SCK_3 means MOSI is on SERCOMn.0 and SCK is on SERCOMn.3
// SERCOM_RX_PAD_1 means MISO on SERCOMn.1
SPIClass mySPI (&sercom2, 3, 5, 4, SPI_PAD_0_SCK_3, SERCOM_RX_PAD_1);

// https://github.com/adafruit/Adafruit_DotStar/pull/20

void setup() {
  Serial.begin(115200);
 
  // do this first, for Reasons

  
  mySPI.begin();
 
  // Assign pins 3, 4, 5 to SERCOM & SERCOM_ALT
  pinPeripheral(3, PIO_SERCOM_ALT); // MISO
  pinPeripheral(4, PIO_SERCOM_ALT); // SCK
  pinPeripheral(5, PIO_SERCOM);     // MOSI
}
 
uint8_t i=0;
void loop() {
  Serial.println(i);
  mySPI.beginTransaction(SPISettings(8000000, MSBFIRST, SPI_MODE0));
  mySPI.transfer(i++);
  mySPI.endTransaction();
}