NodeMCU DS18B20 Hotspot

nodemcu_ds18b20_hotspot.ino

#include <ESP8266WiFi.h>
#include <DallasTemperature.h>
#include <OneWire.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>

#define PIN 5 // nodemcu D1

OneWire oneWire(PIN);
DallasTemperature sensors(&oneWire);
double celsius;

const char* ssid = "mynetwork";
const char* password = "myappassword";
int refresh = 3;
String html = "<meta http-equiv=\"refresh\" content=\"" + String(refresh) + "\" />";

ESP8266WebServer server(80);
void handleRoot()
{
  server.send(200, "text/html", html + "<h1>" + String(celsius) + "</h1>");
}

void setup()
{
  Serial.begin(115200);
  delay(10);

  Serial.print("Access point...");

  WiFi.softAP(ssid, password);
  IPAddress myIP = WiFi.softAPIP();
  
  Serial.print("IP address: ");
  Serial.println(myIP);
  
  server.on("/", handleRoot);
  server.begin();
  Serial.println("HTTP server started");

  sensors.begin();
}

void loop()
{
  sensors.requestTemperatures();
  celsius = sensors.getTempCByIndex(0);
  
  Serial.print("  Temperature = ");
  Serial.print(celsius);
  Serial.println(" Celsius, ");

  server.handleClient();
  
  delay(refresh * 1000);
}