nodemcu-test/test.ino

#include <OneWire.h>
#include <DallasTemperature.h>
#include <DS18B20Events.h>

// Pin for DS18B20
#define ONE_WIRE_BUS 4

// Init Onewire and DallasTemperature
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature dallasTemperature(&oneWire);

//Init thermometer with index 0 (default)
DS18B20Events thermometer(0);

void setup() {
  Serial.begin(115200); 
  delay(1000);
  Serial.println("Booting...");
  pinMode(13, OUTPUT); //GPIO 13 = Pin D7

  DS18B20Events::setup(&dallasTemperature); // Link DS18B20Events to DallasTemperature object
	DS18B20Events::setInterval(5000); // Set min interval in milliseconds between 2 measurements. Default 10000 set in setup() method.

	thermometer.onChange = temperatureChanged;

  Serial.println("Setup Done.");
}

void loop() {
  thermometer.loop(); // Mandatory to measure temperature and fire an event if needed
  // Serial.println("Hello World");
  digitalWrite(13, HIGH);
  delay(100);
  digitalWrite(13, LOW);
  delay(100);
}

void temperatureChanged(uint8_t index, float tempC)
{
	Serial.print(tempC);
	Serial.print(" new tempC at index ");
	Serial.println(index);
}