sender-node.ino

#include <Uttr.h>

#define INTERVAL 2000

unsigned long previous = 0;
String previousId = "";

const char * ssid = "your-router-ssid";
const char * pass = "your-router-password";
const char * deviceId = "enter-any-unique-id";
const char * username = "your-username";
const char * accessKey = "your-access-key";
const char * nameSpace = "your-name-space";
const char * dataChannel = "rfid-data-channel";

void setup() {
  Serial.begin(115200);
  Uttr.onEvent(eventListener);
  Uttr.begin(deviceId, username, accessKey, nameSpace, ssid, pass);
  Uttr.setCallback(callback);

  setupRfid();
}

void loop() {
  Uttr.run();

  unsigned long now = millis();
  if (now - previous > INTERVAL) {
    previous = now;
    previousId = "";
  }

  String data = processRfid();

  if (!data.equalsIgnoreCase("")) {
    Uttr.publish(dataChannel, data.c_str(), true);
  }
}

void callback(char* topic, byte* payload, unsigned int payloadLength) {
  String sTopic = Uttr.toString(topic);
  String sPayload = Uttr.toString(payload, payloadLength);
  Serial.print(sTopic);
  Serial.print(": ");
  Serial.println(sPayload);
}

void eventListener(ConnectionEvent event) {
  switch (event) {
    case NOT_CONNECTED_TO_WIFI:
      Serial.println("Not Connected to WiFi");
      break;
    case CONNECTING_TO_WIFI:
      Serial.println("Connecting to WiFi");
      break;
    case CONNECTED_TO_WIFI:
      Serial.println("Connected to WiFi");
      break;
    case NOT_CONNECTED_TO_MQTT_SERVER:
      Serial.println("Not Connected to MQTT Server");
      break;
    case CONNECTED_TO_MQTT_SERVER:
      Serial.println("Connected to MQTT Server");
      Uttr.subscribe(dataChannel);
      break;
    case AP_MODE:
      Serial.println("AP Mode");
      break;
    default:
      break;
  }
}