Arduino can't show out respond get from mqtt server through esp8266

Question

I'm trying to let my Arduino and esp8266 send data to thingsboard and then subscribe to thingsboard's mqtt channel and get a timestamp from it but for some unknown reason, it just doesn't work. Checked server-side and it was ok, tried postman to simulate request and also getting the correct response from the server. Also, I had read the documentation about esp8266 and it somehow did state that it only can have 1 connection simultaneously. But tried to let my Arduino to only subscribe to channel but it still doesn't work.

My code:(I'm using Arduino Mega for this)

#include "DHT.h"
#include <WiFiEspClient.h>
#include <WiFiEsp.h>
#include <WiFiEspUdp.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include <TimeLib.h>

#define WIFI_AP "CEC"
#define WIFI_PASSWORD "#CEC@2017@CEC#"

#define TOKEN "A1_TEST_TOKEN"

// DHT
#define DHTPIN 2
#define DHTTYPE DHT22

char thingsboardServer[] = "192.168.0.250";

// Initialize the Ethernet client object
WiFiEspClient espClient;

// Initialize DHT sensor.
DHT dht(DHTPIN, DHTTYPE);

PubSubClient client(espClient);

int status = WL_IDLE_STATUS;
unsigned long lastSend;
unsigned long lastSync;

void setup() {
  // initialize serial for debugging
  Serial.begin(9600);
  Serial1.begin(9600);
  Serial2.begin(9600);

  //serial pin
      pinMode(LED_RUN_pin, OUTPUT);

  //dht.begin();
  InitWiFi();
  lastSend = 0;
  lastSync = 0;
  //client subscribe thingsboard rpc PUBLISH msg
  client.setServer( thingsboardServer, 1883 );
   client.setCallback(on_message);
}

void loop() {
  status = WiFi.status();
  if ( status != WL_CONNECTED) {
    while ( status != WL_CONNECTED) {
      Serial.print("Attempting to connect to WPA SSID: ");
      Serial.println(WIFI_AP);
      // Connect to WPA/WPA2 network
      status = WiFi.begin(WIFI_AP, WIFI_PASSWORD);
      delay(500);
    }
  }

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

  if ( millis() - lastSend > 30000 ) { // Update and send after 30 seconds
    getAndSendTemperatureAndHumidityData();
    lastSend = millis();
  }

  client.loop();
}

void getAndSendTemperatureAndHumidityData()
{
  Serial.println("Collecting temperature data.");

  // Reading temperature or humidity takes about 250 milliseconds!
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.print(" *C ");

  String temperature = String(t);
  String humidity = String(h);

  // Prepare a JSON payload string
  String payload = "{";
  payload += "\"temperature\":"; payload += temperature; payload += ",";
  payload += "\"humidity\":"; payload += humidity;
  payload += "}";

  // Send payload
  char attributes[100];
  payload.toCharArray( attributes, 100 );
  client.publish( "v1/devices/me/rpc/request/1", attributes , 1);
  //Serial.println( attributes );
}


  // Prepare a JSON payload string
 String payload = "{method: getTime, params:{}}";

  // Send payload
  char attributes[100];
  payload.toCharArray( attributes, 100 );
  client.publish( "v1/A1_TEST_TOKEN/rpc", attributes );
  //Serial.println( attributes );
}

void InitWiFi()
{ 
  // initialize serial for ESP module
  Serial1.begin(9600);
  // initialize ESP module
  WiFi.init(&Serial1);
  // check for the presence of the shield
  if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi shield not present");
    // don't continue
    while (false);
  }

  Serial.println("Connecting to AP ...");
  // attempt to connect to WiFi network
  while ( status != WL_CONNECTED) {
    // Connect to WPA/WPA2 network
    status = WiFi.begin(WIFI_AP, WIFI_PASSWORD);
    delay(500);
  }
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    //Serial.print("Connecting to Thingsboard node ...");
    // Attempt to connect (clientId, username, password)
    if ( client.connect("Arduino Uno Device", TOKEN, NULL) ) {
     Serial.println( "[DONE]" );
      delay(500);
     // Serial.println("Subscribing RPC");
     client.subscribe("v1/devices/me/rpc/request/+");
    } else {
      Serial.print( "[FAILED] [ rc = " );
      Serial.print( client.state() );
      Serial.println( " : retrying in 20  seconds]" );
      // Wait 20 seconds before retrying
      delay( 20000 );
    }
  }
}

void printDigits(int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  Serial.print(":");
  if(digits < 10)
    Serial.print('0');
  Serial.print(digits);
}

// The callback for when a PUBLISH message is received from the server.
void on_message (char* topic, byte* payload, unsigned int length) {

  //Serial.println("On message");

  char json[length + 1];
  strncpy (json, (char*)payload, length);
  json[length] = '\23';

  Serial.print("Topic: ");
  Serial.println(topic);
  Serial.print("Message: ");
  Serial.println(json); 

  // Decode JSON request
  StaticJsonBuffer<200> jsonBuffer;
  JsonObject& data = jsonBuffer.parseObject((char*)json);

  if (!data.success())
  {
    Serial.println("parseObject() failed");
    return;
  }
}

score 0 · Answer 1 · answered Jun 19 '18 at 12:48

Probably a stupid remark, but is your TOKEN a valid Thingsboard device token? I assume you entered the value A1_TEST_TOKEN to hide your real authentication token.

I also assume you are trying to send sensor data (telemetry) to Thingsboard. Why did you decide to use the RPC API for sending data? I think it might be easier to use the MQTT Device API instead.

I don't have any experience in developing for Arduino. I am using Thingsboard together with a Raspberry PI to write and display sensor data. Hope you find a solution for your problem!

Arduino can't show out respond get from mqtt server through esp8266

1 Answers1