Added hallNode

hallNode.ino

+#include <WiFi.h>
+#include <NTPClient.h>
+#include <WiFiUdp.h>
+#include <PubSubClient.h>
+#include <Wire.h>
+
+// Replace the next variables with your SSID/Password combination
+const char* ssid = "Intz";
+const char* password = "intzintz";
+
+// Add your MQTT Broker IP address, example:
+//const char* mqtt_server = "mqtt.thingspeak.com";
+const char* mqtt_server = "85.119.83.194";
+
+WiFiClient espClient;
+PubSubClient client(espClient);
+long lastMsg = 0;
+char msg[50];
+int value = 0;
+
+WiFiUDP ntpUDP;
+NTPClient timeClient(ntpUDP);
+
+String formattedDate;
+String dayStamp;
+String timeStamp;
+
+void setup() {
+  Serial.begin(115200); 
+  setup_wifi();
+  client.setServer(mqtt_server, 1883);
+  client.setCallback(callback);
+
+  pinMode(LED_BUILTIN, OUTPUT);
+
+  timeClient.begin();
+  timeClient.setTimeOffset(10800);
+}
+
+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.println("WiFi connected");
+  Serial.println("IP address: ");
+  Serial.println(WiFi.localIP());
+}
+
+void callback(char* topic, byte* message, unsigned int length) {
+
+  Serial.print("Message arrived on topic: ");
+  Serial.print(topic);
+  Serial.print(". Message: ");
+  String messageTemp;
+  int hallReading;
+  
+  for (int i = 0; i < length; i++) {
+    Serial.print((char)message[i]);
+    messageTemp += (char)message[i];
+  }
+  hallReading = messageTemp.toInt();
+  Serial.println();
+
+  // If a message is received on the topic esp32/output, you check if the message is either "on" or "off". 
+  //if (String(topic) == "channels/695112/subscribe/fields/field2") {
+  if (String(topic) == "embedded/hall") {
+    if(hallReading <= 0){
+      Serial.println("negative");
+      digitalWrite(LED_BUILTIN, HIGH);
+    }
+    else if(hallReading > 0){
+      Serial.println("positive");
+      digitalWrite(LED_BUILTIN, LOW);
+    } 
+  }
+}
+
+void reconnect() {
+  // Loop until we're reconnected
+  while (!client.connected()) {
+    Serial.print("Attempting MQTT connection...");
+    // Attempt to connect
+    if (client.connect("ESP8266Client")) {
+      Serial.println("connected");
+      // Subscribe
+      //client.subscribe("channels/695112/subscribe/fields/field2");
+      client.subscribe("embedded/hall");
+    } else {
+      Serial.print("failed, rc=");
+      Serial.print(client.state());
+      Serial.println(" try again in 5 seconds");
+      // Wait 5 seconds before retrying
+      while (WiFi.status() != WL_CONNECTED) {
+        setup_wifi();
+      }
+      delay(5000);
+    }
+  }
+}
+void get_time(){
+  while(!timeClient.update()) {
+    timeClient.forceUpdate();
+  }
+  formattedDate = timeClient.getFormattedDate();
+
+  int splitT = formattedDate.indexOf("T");
+  dayStamp = formattedDate.substring(0, splitT);
+  Serial.print("DATE: ");
+  Serial.println(dayStamp);
+    // Extract time
+  timeStamp = formattedDate.substring(splitT+1, formattedDate.length()-1);
+  Serial.print("HOUR: ");
+  Serial.println(timeStamp);
+}
+
+
+void loop() {
+
+  if (!client.connected()) {
+    reconnect();
+  }
+  client.loop();
+  
+  long now = millis();
+  if (now - lastMsg > 1000) {
+    
+    lastMsg = now;
+
+    int val = hallRead();
+    get_time();
+    
+    char hallString[8];
+    char string_to_send[25];
+    char time_to_send[10];
+    dtostrf(val, 1, 2, hallString);
+    //timeStamp.toCharArray(time_to_send, 10);
+
+    //strcpy(string_to_send, hallString);
+    //strcat(string_to_send, ";");
+    //strcat(string_to_send, time_to_send);
+    
+    //client.publish("channels/695112/publish/fields/field2/V8DD4LPOL4XZGM8V", hallString);
+    client.publish("embedded/hall", hallString);
+    
+  }
+}