Analyzing I2C signals

#include "Adafruit_Si7021.h"

Adafruit_Si7021 sensor = Adafruit_Si7021();

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(9600);
  Serial.println("Start Si7021");

  if (!sensor.begin()) {
    Serial.println("Did not find Si7021 sensor!");
    while (true) {}
  } else {
    Serial.println("Temperature in Celsius:");
  }
}

void loop() {
  Serial.println(sensor.readTemperature());

  digitalWrite(LED_BUILTIN, HIGH);
  delay(1000);

  digitalWrite(LED_BUILTIN, LOW);
  delay(1000);
}

BOARD?=arduino:avr:uno
PORT?=/dev/cu.usbmodem14*

.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) ./

flash:
	arduino-cli upload --fqbn $(BOARD) --port $(PORT)

clean:
	rm -r build