Create a blinky LED with Arduino UNO board with ATmega328p microcontroller.
#include <Arduino.h>
void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(9600);
}
void loop() {
  Serial.println("HIGH");
  digitalWrite(LED_BUILTIN, HIGH);
  delay(1000);
  Serial.println("LOW");
  digitalWrite(LED_BUILTIN, LOW);
  delay(1000);
}BOARD?=arduino:avr:uno
PORT?=/dev/cu.usbmodem14*
BUILD=build
.PHONY: default lint all flash clean
default: lint all flash clean
lint:
	cpplint --extensions=ino --filter=-legal/copyright *.ino
all:
	arduino-cli compile --fqbn $(BOARD) --output-dir $(BUILD) ./
flash:
	arduino-cli upload --fqbn $(BOARD) --port $(PORT) --input-dir $(BUILD)
clean:
	rm -r build