arduino.ino

#include <SPI.h>
#include <Ethernet.h>
#include "string.h"
#include "iotconnector.h"

// Some Ethernet shields have a MAC address printed on a sticker on the shield;
// fill in that address here, or choose your own at random:
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

char pubkey[] = "demo";
char subkey[] = "demo";
char channel[] = "iotchannel";
char uuid[] = "Arduino";

iotbridge arduino;

void initialize(){
        Serial.begin(9600);
	Serial.println("Serial set up");

	while (!Ethernet.begin(mac)) {
		Serial.println("Ethernet setup error");
		delay(1000);
	}
	Serial.println("Ethernet set up");
}

void do_something(String value){
          Serial.println("in the callback");
          Serial.println(value);
}

void setup()
{
	initialize();

	arduino.init( pubkey, subkey, uuid); 
	Serial.println("PubNub set up");
}

void loop()
{      
  	String returnmessage;
	Ethernet.maintain();
        
        //Publish
	Serial.println("publishing a message");
  	arduino.send(channel,"\"Hey There\"");
        

        //Subscribe
	Serial.println("waiting for a message");
  	returnmessage = arduino.connect(channel);
        
        // callback function of sorts, to work with the received message
  	do_something(returnmessage);
	Serial.println();
}

iotconnector.h

#include "PubNub.h"
#include <SPI.h>
#include <Ethernet.h>


class iotbridge{
  public:
  
  const char *publish_key;
  const char *subscribe_key;
  const char *uuid;
  const char *channel;
  const char *message;
  
  bool init(const char *publish_key, const char *subscribe_key, const char *uuid);
  bool send(const char *channel, const char *message);
  String connect(const char *channel);
  
};
  
bool iotbridge::init(const char *publish_key, const char *subscribe_key, const char *uuid){
  
  PubNub.begin(publish_key,subscribe_key);
  PubNub.set_uuid(uuid);
}

bool iotbridge::send(const char *channel, const char *message){
  EthernetClient *client;
  client = PubNub.publish(channel,message);
  return client;
}

String iotbridge::connect(const char *channel){
  
  String message = "";
  int i = 0;
  PubSubClient *pclient = PubNub.subscribe(channel);
	if (!pclient) {
		return 0;
	}
  while (pclient->wait_for_data()) {
		char c = pclient->read();
    message += c;
	}

	pclient->stop();
	Serial.println();
  return message;
  
}
  

I have the same problem with @hafizmaster93, can somebody help us?

same problem....

In file included from C:\Arduino\pub_nub_test\sketch_aug29a\sketch_aug29a.ino:4:0:

C:\Arduino\libraries\PubNub/iotconnector.h: In member function 'String iotbridge::connect(const char*)':

C:\Arduino\libraries\PubNub/iotconnector.h:39:10: error: converting to 'String' from initializer list would use explicit constructor 'String::String(int, unsigned char)'

return 0;

      ^

exit status 1

Error compiling.

no idea what it actually means but cannot compile code.

You are attempting to return an integer in a function with a return type of String.
It should compile if you change line 39 of iotconnector.h to return "";

NOTE: I have not looked at the rest of the code to verify that this will not cause other problems.