ESP8266 script to read DS18B20 sensors over 1W and broadcast Signal K JSON over udp

gistfile1.txt

#include <OneWire.h>
#include <DallasTemperature.h>
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <SPI.h>
#include <Wire.h>
#include <ESP8266WebServer.h>
#include <DNSServer.h>
#include <WifiServer.h>

WiFiUDP g_udp;
IPAddress broadcast;
WiFiServer server(80);

const int g_port = 8888;

#define ONE_WIRE_BUS D4

OneWire oneWire(ONE_WIRE_BUS);

DallasTemperature sensors(&oneWire);
uint8_t count = 0;

void printAddress(DeviceAddress deviceAddress) {
  for (uint8_t i = 0; i < 8; i++)
  {
    if (deviceAddress[i] < 16) Serial.print("0");
    Serial.print(deviceAddress[i], HEX);
  }
  Serial.print(":");
}


void setup(void)
{
  Serial.begin(9600);
  Serial.println("Startup");

  WiFi.begin("XXX", "YYY");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected...");
  Serial.println(WiFi.localIP());

  server.begin();
  Serial.println("Server started");

  broadcast = WiFi.localIP();
  //hardcoded broadcast address
  broadcast[3] = 255;
  Serial.println(broadcast);

  g_udp.beginMulticast(WiFi.localIP(), broadcast, g_port);
}

void sendUdp(DeviceAddress deviceAddress, float value) {
  printAddress(deviceAddress);
  Serial.println(value);

  g_udp.beginPacketMulticast(broadcast, g_port, WiFi.localIP());

  g_udp.print("{\"updates\":[{\"$source\":\"1w.");

  for (uint8_t i = 0; i < 8; i++)
  {
    if (deviceAddress[i] < 16) Serial.print("0");
    g_udp.print(deviceAddress[i], HEX);
  }
  g_udp.print(",\"values\":[{\"path\":\"temperature\",\"value\":");
  g_udp.print(value);
  g_udp.print("}]}]}");

  g_udp.write("\n");
  Serial.println(g_udp.endPacket());
  yield();
}

void loop(void)
{

  sensors.begin();

  int numberOfDevices = 0;

  numberOfDevices = sensors.getDeviceCount();
  Serial.print(numberOfDevices, DEC);
  Serial.println(" devices");

  sensors.requestTemperatures();

  DeviceAddress tempDeviceAddress;

  for(int i=0;i<numberOfDevices; i++) {
    if(sensors.getAddress(tempDeviceAddress, i))
  	{
      float tempC = sensors.getTempC(tempDeviceAddress);
      sendUdp(tempDeviceAddress, tempC);
  	}
  }
  delay(1000);
}