Arduino Socket.io shows disconnected when delay() is used - c

Question

I am new to Arduino and facing an issue. I am implementing socket in Arduino for ESP8266 . It works as expected when I am not using delay() or not using someFunction(). As soon as i use delay or do some processing than i am getting connection disconnected one server socket.
#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <ArduinoJson.h>
#include <WebSocketsClient.h>
#include <SocketIOclient.h>
#include <Hash.h>
ESP8266WiFiMulti WiFiMulti;
SocketIOclient socketIO;
#define USE_SERIAL Serial1
void socketIOEvent(socketIOmessageType_t type, uint8_t * payload, size_t length) {
switch(type) {
case sIOtype_DISCONNECT:
USE_SERIAL.printf("[IOc] Disconnected!\n");
break;
case sIOtype_CONNECT:
USE_SERIAL.printf("[IOc] Connected to url: %s\n", payload);
break;
case sIOtype_EVENT:
USE_SERIAL.printf("[IOc] get event: %s\n", payload);
break;
case sIOtype_ACK:
USE_SERIAL.printf("[IOc] get ack: %u\n", length);
hexdump(payload, length);
break;
case sIOtype_ERROR:
USE_SERIAL.printf("[IOc] get error: %u\n", length);
hexdump(payload, length);
break;
case sIOtype_BINARY_EVENT:
USE_SERIAL.printf("[IOc] get binary: %u\n", length);
hexdump(payload, length);
break;
case sIOtype_BINARY_ACK:
USE_SERIAL.printf("[IOc] get binary ack: %u\n", length);
hexdump(payload, length);
break;
}
}
void setup() {
// USE_SERIAL.begin(921600);
USE_SERIAL.begin(115200);
//Serial.setDebugOutput(true);
USE_SERIAL.setDebugOutput(true);
USE_SERIAL.println();
USE_SERIAL.println();
USE_SERIAL.println();
for(uint8_t t = 4; t > 0; t--) {
USE_SERIAL.printf("[SETUP] BOOT WAIT %d...\n", t);
USE_SERIAL.flush();
delay(1000);
}
// disable AP
if(WiFi.getMode() & WIFI_AP) {
WiFi.softAPdisconnect(true);
}
WiFiMulti.addAP("SSID", "passpasspass");
//WiFi.disconnect();
while(WiFiMulti.run() != WL_CONNECTED) {
delay(100);
}
String ip = WiFi.localIP().toString();
USE_SERIAL.printf("[SETUP] WiFi Connected %s\n", ip.c_str());
// server address, port and URL
socketIO.begin("10.11.100.100", 8880);
// event handler
socketIO.onEvent(socketIOEvent);
}
unsigned long messageTimestamp = 0;
void loop() {
socketIO.loop();
uint64_t now = millis();
if(now - messageTimestamp > 2000) {
messageTimestamp = now;
// creat JSON message for Socket.IO (event)
DynamicJsonDocument doc(1024);
JsonArray array = doc.to<JsonArray>();
// add evnet name
// Hint: socket.on('event_name', ....
array.add("event_name");
// add payload (parameters) for the event
JsonObject param1 = array.createNestedObject();
param1["now"] = now;
// JSON to String (serializion)
String output;
serializeJson(doc, output);
// Send event
socketIO.sendEVENT(output);
// Print JSON for debugging
USE_SERIAL.println(output);
}
//NEED TO DO SOME PROCESSIONG
delay(2000);
someFuntion();
}
void someFunction(){
//some processing that consume the time
}

Answer 1

You are getting timeout on server side.
When you are making delay(10000) esp8266 is just hanging on some loop (as a delay implementation) - any other code is not executed due this time. So when the server is not getting any data it disconnects client.
The solution (easy way) is to make a new connection every time you want to send data. In pseudocode it will look like this:
void loop(){
connectToServer();
sendData();
Disconnect();
delay(1000);
SomeFunction();
}
Then it should work.
The more complicated method is to familiarize yourself with the concept of Events and callbacks and get rid of delay() function. Or try to use esp_rtos_sdk witch is asynchronous tasks concepts RTOS framework.
Have fun!
Edited:
After refreshed the code I'm able to tell more about it, so I'm editing the previous post.
The quickest way to make it work(partly) is to remove the delay(2000) statement - because this If() statement is handling sending messages in 2 seconds interval. As I see you may wan't to put this void someFunction() to this if() statement too. This will make "some processing" in 2 seconds interval.
socketIO.loop() is handling maintaining connection with server and sending event's to server so it has to be call as quick as plausible. In case with delay you are getting socket timeout and disconnection.
void loop() function must be shortest as plausible to maintain the connection. Probably it is 500ms or so - regarding to you experiments. So any delay's is not plausible. If you need more processing try to familiarize with event processing. The easiest way is to declare flags as Boolean and timers counting time intervals. When timer is lunched it's sets the flag as true and you may process function.
Websockets on ESP(or other embedded microprocessors) are hard for beginners because they are time dependent. You need to have short processing loop or some of asynchronous methods used.
I hope, that I help.