Accessing Hidden Pins on the Arduino Zero

In this video we look at how you can access six additional digital pins from your Arduino Zero board. We also take a look at some flexible wired communication options you can take advantage of on the Arduino Zero.

Link to Adafruit tutorial referenced in the video: https://learn.adafruit.com/using-atsamd21-sercom-to-add-more-spi-i2c-serial-ports/creating-a-new-serial

Path on Windows to get to variants.cpp: C:\Users\yourname\AppData\Local\Arduino15\packages\arduino\hardware\samd\1.6.6

Zero pin out chart from video:

//**********************Arduino Code from the video*********************
//This code is free to use and modify at your own risk

bool tog = false; //used to toggle LEDs on and off

void setup() {
  pinMode(38,OUTPUT); //This is the pin labeled "ATN"
  pinMode(22,OUTPUT); //This is MISO pin on ICSP header
  pinMode(20,OUTPUT); //This is SDA pin
  SerialUSB.begin(57600); //this is the native USB port
  Serial.begin(57600); //this is the programming port
  Serial1.begin(57600); //this is for pins D0 and D1
}

void loop() {

  if(tog) { //set each of the pins to high to turn LEDs on
    digitalWrite(38,HIGH);
    digitalWrite(22,HIGH);
    digitalWrite(20,HIGH);
    tog = false;
  }
  else { //set each pin to low to turn them off
    digitalWrite(38,LOW);
    digitalWrite(22,LOW);
    digitalWrite(20,LOW);
    tog = true;
  }

  delay(1500); //delsy for 1.5 seconds
}