Example showing full range DAC usage on ATtiny412 using megaTinyCore as well as useful PIN numbers

ATtiny412.ino

/*
 * In this example, I'm using megaTinyCore with the ATtiny412 Development Board
 * by Leonerd https://www.tindie.com/products/leonerd/attiny412-development-board/
 * 
 * The pins for megaTinyCore and 412 are found in:
 * /Users/jensa/Library/Arduino15/packages/megaTinyCore/hardware/megaavr/2.6.10/variants/txy2/pins_arduino.h
 * 
 * Useful pins:
 * Outputs are referenced using "PIN_PA1"
 * I2C is referenced on PIN_WIRE_SDA (PA1) / PIN_WIRE_SCL (PA2)
 * SPI is referenced on PIN_SPI_MISO/PIN_SPI_SCK/PIN_SPI_MOSI
 * Analog pins match their PA number, so PIN_A3 is PA3 is pin 4
 * DAC is referenced using DAC_PIN, but output is on PA6
 */

// listing the Arduino pin numbers on physical device
#define PA0 5
#define PA1 2
#define PA2 3
#define PA3 4
#define PA6 0
#define PA7 1

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  
  // Technically not legal to set DAC reference at 4.3V,
  // but this produces a full range output?
  DACReference(INTERNAL4V3); 
  delay(100);
  analogWrite(PIN_PA6, 255);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH); 
  delay(500);
  digitalWrite(LED_BUILTIN, LOW); 
  delay(500); 
}