ESP8266 + WiFiManager + pubsubclient - arduino

Question

I'm using an ESP8266 and want to control it using MQTT with the MQTT server being my Synology DS415+. I want the ESP to sit in a place where I cannot access it using serial once it is installed, so I need to be able to configure it's Wifi-Credentials and the MQTT-Server IP, Port and credentials using WiFi.
Thus I decided that the WiFiManager-Library and the PubSubClient-Library can do this for me. The problem is: I cannot get PubSubClient to work using WiFiManager, because I haven't yet found out how I can tell PubSubClient the right "client" to use.
The following example works on my ESP, however it does not allow for dynamic configuration of the ESPs Wifi: https://github.com/knolleary/pubsubclient/blob/master/examples/mqtt_esp8266/mqtt_esp8266.ino
I came up with the following:
http://pastebin.com/t5evEy1i
This however does not work, its output via serial is the following:
mounting FS...
mounted file system
reading config file
opened config file
{"mqtt_server":"192.168.1.250","mqtt_port":"9001","switch_token":"BackupSwitch"}
parsed json
*WM: Adding parameter
*WM: server
*WM: Adding parameter
*WM: port
*WM: Adding parameter
*WM: blynk
*WM:
*WM: AutoConnect
*WM: Reading SSID
*WM: SSID:
*WM: XXX
*WM: Reading Password
*WM: Password: XXX
*WM: Connecting as wifi client...
*WM: Connection result:
*WM: 3
*WM: IP Address:
*WM: 192.168.1.74
connected...yeey :)
local ip
192.168.1.74
Attempting MQTT connection...192.168.1.250:9001
failed, rc=-2 try again in 5 seconds
Attempting MQTT connection...192.168.1.250:9001
failed, rc=-2 try again in 5 seconds
I'm pretty sure the problem lies in the definition of the PubSubClient in line 17 and 18:
WiFiClient espClient;
PubSubClient client(espClient);
But I don't know how to extract the client from WiFiManager to give it to the PubSubClient-Library.
What I need is how to get an object that is equal to what WiFiClient or EthernetClient creates, that WiFiManager probably creates and that I can give as an argument to PubSubClient client(espClient);
Does anyone have any idea how to achieve this? Thanks in advance.

Answer 1

You don't need to pull anything out of WiFiManager since it is using WiFiClient. All you need to do is:
#include <ESP8266WiFi.h>
#include <WiFiManager.h>
#include <PubSubClient.h>
WiFiClient espClient;
PubSubClient client(espClient);
void mqttCallback(char* topic, byte* payload, unsigned int length) {
// message received
}
void mqttReconnect() {
// reconnect code from PubSubClient example
}
void setup() {
WiFiManager wifiManager;
wifiManager.setTimeout(180);
if(!wifiManager.autoConnect("AutoConnectAP")) {
Serial.println("failed to connect and hit timeout");
delay(3000);
ESP.reset();
delay(5000);
}
Serial.println("connected...yeey :)");
client.setServer(mqtt_server, 1883);
client.setCallback(mqttCallback);
}
void loop() {
if (!client.connected()) {
mqttReconnect();
}
client.loop();
yield();
}