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Last active April 3, 2018 20:29
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#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.println("Serial set up");
while (!Ethernet.begin(mac)) {
Serial.println("Ethernet setup error");
Serial.println("Ethernet set up");
void do_something(String value){
Serial.println("in the callback");
void setup()
arduino.init( pubkey, subkey, uuid);
Serial.println("PubNub set up");
void loop()
String returnmessage;
Serial.println("publishing a message");
arduino.send(channel,"\"Hey There\"");
Serial.println("waiting for a message");
returnmessage = arduino.connect(channel);
// callback function of sorts, to work with the received message
#include "PubNub.h"
#include <SPI.h>
#include <Ethernet.h>
class iotbridge{
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){
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;
return message;
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mskoczen commented Apr 3, 2018

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.

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