esp8266-01 code for sonoff sensors

/*********
   updated 8/12/9 kentm
  Complete project details at https://randomnerdtutorials.com
  adapted from multisensor NodeRed project. Each sketch addresses
  one modified sonoff basic device that must match "sonoffxxX"
  Search sonoffxxX and replace with current number (four)
  The "S" in the name indicates this a sensor
  modified for RCWL-0516 sensor and ESP826601
  Adjust total "ON" time in final loop statement in millis
*********/

// Load libraries
#include <ESP8266WiFi.h>
#include <PubSubClient.h>


// Replace with your network credentials
const char* ssid     = "xxxxxxx";
const char* password = "xxxxxxxx";

// Change the variable to your Raspberry Pi IP address,
// so it connects to your MQTT broker
const char* mqtt_server = "xxx.xxx.x.x";


// Initializes the espClient. You should change the
// espClient name if you have multiple ESPs running
// in your home automation system
WiFiClient espClient;
PubSubClient client(espClient);


const int motionSensor = 2;

// Timers - Auxiliary variables
unsigned long now = millis();
unsigned long lastMeasure = 0;
boolean startTimer = false;
unsigned long currentTime = millis();
unsigned long previousTime = 0;

// Don't change the function below.
// This function connects your ESP8266 to your router
void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected - ESP IP address: ");
  Serial.println(WiFi.localIP());
}

// This functions is executed when some device publishes
// a message to a topic that your ESP8266 is subscribed to
// Change the function below to add logic to your program,
// so when a device publishes a message to a topic that
// your ESP8266 is subscribed you can actually do something

void callback(String topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String messageTemp;

  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    messageTemp += (char)message[i];
  }
  Serial.println();

  Serial.println();
}

// This functions reconnects your ESP8266 to your MQTT broker
// Change the function below if you want to subscribe to
// more topics with your ESP8266
void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
      // Subscribe or resubscribe to a topic
      // You can subscribe to more topics (to control more outputs)
      client.subscribe("esp8266/output");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

// Checks if motion was detected and the sensors are armed.
// Then, starts a timer.
void detectsMovement() {
  Serial.println("MOTION DETECTED!");
  client.publish("esp8266/motion", "MOTION DETECTED-xxX!");
  client.publish("home/office/sonoff-xxX","on");
  previousTime = millis();
  startTimer = true;
}

void setup() {


  // Serial port for debugging purposes
  Serial.begin(115200);

  // RDR Motion Sensor mode, then set interrupt function and RISING mode
  pinMode(motionSensor, INPUT);
  attachInterrupt(digitalPinToInterrupt(motionSensor), detectsMovement, RISING);


  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  // Timer variable with current time
  now = millis();

  // After 150 seconds have passed since motion was detected,
  // publishes a "No motion" message
  if ((now - previousTime > 150000)&& startTimer) {
    client.publish("esp8266/motion", "NO MOTION-xxX");
    client.publish("home/office/sonoffxxX","off");
    Serial.println("Motion stopped");
    startTimer = false;
  }
}