Timeout Issue in MQTTClient through ESP32

[architmuchhal12]

Hello,

I am using a Sparkfun ESP32 with Adafruti FONA 808 to connect to an MQTT Server.

Hardware:

Board: Sparkfun ESP32 Thing Core Installation/update date using this version: 41e36a7 IDE name: Arduino IDE Flash Frequency: 80Mhz Upload Speed: 115200

I am using the following 2 libraries.

1. TinyGSM (https://github.com/vshymanskyy/TinyGSM)
2. PubSub Client (https://github.com/knolleary/pubsubclient)

I have modified the TinyGSM/examples/MqttClient/MQTTClient.ino accordingly.

I am using hardware serial at 115200 baud rate. The issue I am facing is the serial monitor displays the reason for no connection as (-4) which is due to Timeout Value. I have also tried increasing the timeout value in the library but with no success.

I know this issue isn't relevant to ESP32 but if I could get any help, it would be really great.

Please suggest me a solution! Thanks!

Init Code:

// Select your modem:
#define TINY_GSM_MODEM_SIM800
//#define TINY_GSM_MODEM_SIM900
//#define TINY_GSM_MODEM_A6
//#define TINY_GSM_MODEM_M590

#include <TinyGsmClient.h>
#include <PubSubClient.h>
#include "Adafruit_FONA.h"

// Default pins for Feather 32u4 FONA
#define FONA_RST 25
HardwareSerial fonaSerial(1);
Adafruit_FONA fona = Adafruit_FONA(FONA_RST);

// Your GPRS credentials
// Leave empty, if missing user or pass
const char apn[]  = "wholesale";
const char user[] = "0";
const char pass[] = "0";

TinyGsm modem(fonaSerial);
TinyGsmClient client(modem);
PubSubClient mqtt(client);

const char* broker = "***********";
const char* userName = "******";

FONA808 Setup:

// Set FONA module baud rate
  fonaSerial.begin(115200, SERIAL_8N1, 33, 32);
  if (! fona.begin(fonaSerial)) {
    Serial.println(F("Couldn't find FONA"));
    while (1);
  }
  Serial.println(F("FONA is OK"));
  Serial.println(F("Found FONA808 (v2) "));
  delay(1000);

Serial Monitor Output:

Attempting to open comm with ATs
    ---> AT
    <--- BU��
    ---> AT
    <--- ÿ
    ---> AT
    <--- 
    ---> AT
    <--- ÿ
    ---> AT
    <--- AT
    ---> AT
    <--- AT
    ---> ATE0
    <--- ATE0
    ---> ATE0
    <--- OK
    ---> AT+CVHU=0
    <--- OK
    ---> ATI
    <--- SIM808 R14.18

OK

FONA is OK
Found FONA808 (v2) 
Initializing modem...
Waiting for network... OK
Connecting through(apn)---> wholesale----->>> OK and Connected to GPRS
Setting up server----->>  Server Set
Connecting to: *********** ----->> Fail
Error code number for no connection: -4

[androidcho]

Your library is not initialised properly. Take a look here - https://pubsubclient.knolleary.net/api.html

[architmuchhal12]

I am not sure what error I am making in initializing the PubSub client. Here is my code for the connection to MQTT Broker

Code -

boolean mqttConnect() {
  Serial.print("Connecting to: ");
  Serial.println(broker);
  if (!mqtt.connect("ESP32Client", "user", "password")) {
    Serial.println(" ----->> Fail!");
  }
  else {
    Serial.print("Error code number for no connection: ");
    Serial.println(mqtt.state());
    return false;
  }

I have also tried other combinations from the library for the "connect" function, but none of them returned a success.

[androidcho]

I can't see where your WiFi library is initialised as a client. Take a look at this tutorial, it'll get you up and running. https://techtutorialsx.com/2017/04/24/esp32-publishing-messages-to-mqtt-topic/

[copercini]

@androidcho He is using an external GSM modem (SIM808) instead of Wifi, so don't need the wifi stuff =)

[chris-gunawardena]

@architmuchhal12 This is a working example on the ESP32. It could be a network or port issue. ws:// vs mqtt:// Have you tried connecting to a local server using something like mosca? Also try connecting to your server using a differnt mqtt client like this ot mqtt lens.

[everslick]

This issue is closed, because it looks as if it is not a bug or problem with the ESP32 Arduino core or its support libraries. For general API usage questions or help on specific coding challenges, please visit the arduino-esp32 Gitter channel. If you feel this issue was closed in error, reopen it and comment, why you think this is a bug in the Arduino-Core.