PlatformIO_KitchenPIR/src/main.cpp

#include <Arduino.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>

const int PIR_PIN=23;
const char* ssid = "JoNelsDarlings";
const char* password = "Paris2016";
const char* mqtt_server = "mqtt.ddns.kawomi.com";

WiFiClient espClient;
PubSubClient mqttClient(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE	(50)
char msg[MSG_BUFFER_SIZE];

void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

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

  randomSeed(micros());

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}


void reconnect() {
  // Loop until we're reconnected
  while (!mqttClient.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (mqttClient.connect(clientId.c_str())) {
      Serial.println("MQTT connected");
      // Once connected, publish an announcement...
    } else {
      Serial.print("MQTT failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void send_mqtt(String status, long time_min=0) {
  Serial.print("MQTT Send status ");
  Serial.print(status);
  Serial.print(" mins ");
  Serial.println(time_min);

  const size_t CAPACITY = JSON_OBJECT_SIZE(1);
  StaticJsonDocument<CAPACITY> doc;

  // create an object
  JsonObject object = doc.to<JsonObject>();
  object["status"] = status.c_str();
  if (time_min > 0) {
    object["minutes"] = time_min;
  }

  // serialize the object and send the result to Serial
  static char sensorStatus[150];
  serializeJson(doc, sensorStatus);
  Serial.println(sensorStatus);

  mqttClient.publish("Address/Livorno/Kitchen/PIR", sensorStatus, true);
}


void setup() {
  pinMode(LED_BUILTIN,OUTPUT);
  pinMode(PIR_PIN,INPUT_PULLUP);

  Serial.begin(115200);
  setup_wifi();
  mqttClient.setServer(mqtt_server, 1883);

}

long previousMotionMillis=millis();
short previousState=digitalRead(PIR_PIN);
long previousNoMoNotifyMins=0;
void loop() {
  if (!mqttClient.connected()) {
    reconnect();
  }
  mqttClient.loop();

  short currentState = digitalRead(PIR_PIN);
  if (currentState != previousState) {
    Serial.print("Status changed; currentState: ");
    Serial.print(currentState);
    Serial.print(" previousState: ");
    Serial.println(previousState);
    if (currentState == HIGH) {
      send_mqtt("motion");
      digitalWrite(LED_BUILTIN,HIGH);
      delay(5000);
      digitalWrite(LED_BUILTIN,LOW);
      previousMotionMillis=millis();
    } 
    previousState = currentState;
  }

  long minsSinceLastMotion=(millis()-previousMotionMillis)/(1000*60);
  if ((previousNoMoNotifyMins != minsSinceLastMotion) && (0 != minsSinceLastMotion)) {
    send_mqtt("no_motion",minsSinceLastMotion);
    previousNoMoNotifyMins = minsSinceLastMotion;
  }

  delay(20);
}