How to make an I2C LCD Display work independently even when BLYNK not connected

[khoih]

You can try this very simple code to see if the problem is still there.

#define BLYNK_PRINT Serial

#include <ESP8266_Lib.h>
#include <BlynkSimpleShieldEsp8266.h>


// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "***";

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "***";
char pass[] = "***";

// Hardware Serial on Mega, Leonardo, Micro...
#define EspSerial Serial1

// Change to Serial3 (RX3/TX3 or 15/14 og Mega) if Serial1 is currently used for debugging
//#define EspSerial Serial3

// Your ESP8266 baud rate:
#define ESP8266_BAUD 115200

ESP8266 wifi(&EspSerial);

bool connectBlynk()
{ 
  if (Blynk.connectWiFi(ssid, pass))
    Serial.println("\nWiFi connected. Try Blynk");

  int i = 0;
  while ((i++ < 20) && !Blynk.connect()) 
  {
      BlynkDelay(500);
  }
  
  return Blynk.connected();
}


void setup()
{ 
  // Debug console
  Serial.begin(9600);

  // Set ESP8266 baud rate
  EspSerial.begin(ESP8266_BAUD);
  delay(100);

  Blynk.config(wifi, auth);
  // You can also specify server:
  //Blynk.config(wifi, auth, "blynk-cloud.com");
  //Blynk.config(wifi, auth, "192.168.1.100", 8080);

  if (connectBlynk())
  {
    Serial.println("\nBlynk connected");
  }
  else
  {
    Serial.println("\nBlynk not connected");
  }
}

void loop()
{
  Blynk.run();

  if (!Blynk.connected())
  {
    Serial.println("No Blynk connection. Trying to connect");  
    connectBlynk();
  }
}

1. If it’s OK, then there is some issue with your remaining code, such as auto reset something every 900s, bad pointers, etc…

// connected to something ???
int reset_pin=29;

void espreset()   //TIMELY ESP  RESET
{
digitalWrite (reset_pin,LOW) ;
delay(1000);
digitalWrite (reset_pin,HIGH) ;
//Blynk.begin(auth, wifi, ssid, pass);
connectBlynk();
}
...
void setup()
{
   ....
   timer.setInterval(900000L, espreset);
   ...
}

2. If the issue still persists, change to real WiFi router, mobile provider, or SIM, etc.

Arduino mega + esp

Okay, that makes sense now. People often have problems with Blynk when using a mobile hotspot, as some mobile data providers block the Blynk protocol. Try connecting the Uno/ESP directly to a regular Wi-Fi network, or try connecting to a mobile hotspot that uses a different data provider, or swap the SIM card from a friend into your phone. Pete.

3. You can also change to #define EspSerial Serial3, certainly with moving the ESP-01 wires to new TX3/RX3 (14/15) pins as normally TX1/RX1 (18/19) might be used for Serial debugging.

4. Putting more debugging messages to Serial port will help you to find out where to issue is.

5. Also find out and try different AT firmwares for ESP-01. Some might have bugs. But this is not an issue to discuss in this forum. You can do the research yourself.

Good luck.