NodeMCU keeps disconnecting

Question

I have made a home automation system consisting of a NodeMCU, 4 channel relay board running on Blynk and IFTTT.

At the moment I'm only controlling a string of fairy lights and two LED strips from it, both connected to the relay of course.

The only code running on the NodeMCU is the Blynk ESP8266 Standalone code. Here it is (with the necessary changes of course) -

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

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

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

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

  Blynk.begin(auth, ssid, pass);
  // You can also specify server:
  //Blynk.begin(auth, ssid, pass, "blynk-cloud.com", 80);
  //Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8080);
}

void loop()
{
  Blynk.run();
  // You can inject your own code or combine it with other sketches.
  // Check other examples on how to communicate with Blynk. Remember
  // to avoid delay() function!
}

Now the thing is, the NodeMCU automatically disconnects from the WiFi randomly. Sometimes it reconnects immediately, sometimes it doesn't reconnect at all and I have to keep hitting the reset button to get it working again.

This is really annoying as everything I got connected to the NodeMCU also comes on all of a sudden and scares the hell out of me.

The code is all fine, the power supply is stable (5v 1A), all the cables are in place and the NodeMCU is tucked away in a corner where nobody touches it. I can't seem to work out why is this happening.

Any fixes for this?

Answer 1

I had this same issue with an ESP8266 NodeMCU-12E using Cayenne in the past. It would drop connection for no apparent reason, but no matter what, most of the time it'd never reconnect until a reset. Here's what I did:

CAYENNE_DISCONNECTED(){
  Serial.println(F("Cayenne disconnected, rebooting..."));
  ESP.restart();
}

I've never used Blynk before, but after a quick look, this may do the same thing (untested):

if (! Blynk.connected){
  Serial.println(F("Blynk disconnected, rebooting..."));
  ESP.restart();
}

It effectively reboots the ESP unit if the connection to Blynk drops for any reason.