Issue with PainlessMesh MQTTBridge Example: Unable to Connect to WiFi Network

[alexander_idid]

Hello everyone,

I'm encountering an issue with the MQTTBridge example from the PainlessMesh library in Arduino. The problem lies in the fact that I can't seem to get it to connect to the WiFi network. I've tried with both my home router and using my phone as a WiFi hotspot, but to no avail. Furthermore, I've tested this example on three different ESP boards, and the outcome remains the same.

I've scoured various forums in search of a solution, but unfortunately, I haven't come across an answer that resolves my problem. Has anyone encountered this issue before or have any insights into how to troubleshoot it?

Any help would be greatly appreciated!

Thanks in advance.

this is the Code

//************************************************************
// this is a simple example that uses the painlessMesh library to
// connect to a another network and relay messages from a MQTT broker to the nodes of the mesh network.
// To send a message to a mesh node, you can publish it to "painlessMesh/to/12345678" where 12345678 equals the nodeId.
// To broadcast a message to all nodes in the mesh you can publish it to "painlessMesh/to/broadcast".
// When you publish "getNodes" to "painlessMesh/to/gateway" you receive the mesh topology as JSON
// Every message from the mesh which is send to the gateway node will be published to "painlessMesh/from/12345678" where 12345678 
// is the nodeId from which the packet was send.
//************************************************************

#include <Arduino.h>
#include <painlessMesh.h>
#include <PubSubClient.h>
#include <WiFiClient.h>

#define   MESH_PREFIX     "whateverYouLike"
#define   MESH_PASSWORD   "somethingSneaky"
#define   MESH_PORT       5555

#define   STATION_SSID     "12234"
#define   STATION_PASSWORD "103587825"

#define HOSTNAME "MQTT_Bridge"

// Prototypes
void receivedCallback( const uint32_t &from, const String &msg );
void mqttCallback(char* topic, byte* payload, unsigned int length);

IPAddress getlocalIP();

IPAddress myIP(0,0,0,0);
IPAddress mqttBroker(192, 168, 1, 1);

painlessMesh  mesh;
WiFiClient wifiClient;
PubSubClient mqttClient(mqttBroker, 1883, mqttCallback, wifiClient);

void setup() {

  Serial.begin(115200);

  mesh.setDebugMsgTypes( ERROR | STARTUP | CONNECTION );  // set before init() so that you can see startup messages

  // Channel set to 6. Make sure to use the same channel for your mesh and for you other
  // network (STATION_SSID)
  mesh.init( MESH_PREFIX, MESH_PASSWORD, MESH_PORT, WIFI_AP_STA, 4);
  mesh.onReceive(&receivedCallback);

  mesh.stationManual(STATION_SSID, STATION_PASSWORD);
  mesh.setHostname(HOSTNAME);

  // Bridge node, should (in most cases) be a root node. See [the wiki](https://gitlab.com/painlessMesh/painlessMesh/wikis/Possible-challenges-in-mesh-formation) for some background
  mesh.setRoot(true);
  // This node and all other nodes should ideally know the mesh contains a root, so call this on all nodes
  mesh.setContainsRoot(true);
}

void loop() {
  mesh.update();
  mqttClient.loop();

  if(myIP != getlocalIP()){
    myIP = getlocalIP();
    Serial.println("My IP is " + myIP.toString());

    if (mqttClient.connect("painlessMeshClient")) {
      mqttClient.publish("painlessMesh/from/gateway","Ready!");
      mqttClient.subscribe("painlessMesh/to/#");
    } 
  }
  Serial.println(getlocalIP());
}

void receivedCallback( const uint32_t &from, const String &msg ) {
  Serial.printf("bridge: Received from %u msg=%s\n", from, msg.c_str());
  String topic = "painlessMesh/from/" + String(from);
  mqttClient.publish(topic.c_str(), msg.c_str());
}

void mqttCallback(char* topic, uint8_t* payload, unsigned int length) {
  char* cleanPayload = (char*)malloc(length+1);
  memcpy(cleanPayload, payload, length);
  cleanPayload[length] = '\0';
  String msg = String(cleanPayload);
  free(cleanPayload);

  String targetStr = String(topic).substring(16);

  if(targetStr == "gateway")
  {
    if(msg == "getNodes")
    {
      auto nodes = mesh.getNodeList(true);
      String str;
      for (auto &&id : nodes)
        str += String(id) + String(" ");
      mqttClient.publish("painlessMesh/from/gateway", str.c_str());
    }
  }
  else if(targetStr == "broadcast") 
  {
    mesh.sendBroadcast(msg);
  }
  else
  {
    uint32_t target = strtoul(targetStr.c_str(), NULL, 10);
    if(mesh.isConnected(target))
    {
      mesh.sendSingle(target, msg);
    }
    else
    {
      mqttClient.publish("painlessMesh/from/gateway", "Client not connected!");
    }
  }
}

IPAddress getlocalIP() {
  return IPAddress(mesh.getStationIP());
}

[zwieblum]

I don't see any code that connects to your WiFi, e.g. BSSID/PWD for wifi connection are not there - that's no surprise as you use a mesh. But if you don't have a mesh (some mesh nodes and at least one exit node) you have a problem.

[mathias_lang]

This issue seems like a real head-scratcher, doesn't it? Some folks breeze through it while others are hitting roadblocks left and right. I'm kinda curious, with a bit of confidence, about how exactly that mesh.stationManual(STATION_SSID, STATION_PASSWORD); function works. But hey, what if we give mesh.stationAuto(STATION_SSID, STATION_PASSWORD); a shot too? Any thoughts on how we can crack this mystery together?