Nodemcu esp12e beginners problem

Why I couldn’t able connect my nodemcu with blynk app,always it’s shows offline.after uploading coding compiler shows “hard resetting to RTS pins”.pls help with my problem.

This is normal, it tell you that the NodeMCU is being reset, so that it can execute the code that you’ve just uploaded.

It’s impossible to say why without more information.
What does your serial monitor show?


Nothing sir,blank. I tap the flash button for some seconds and pressed with reset button and released it,onboard led blinks and stopped ,as I am new to this thing it’s create some stress to me,feeling sad.i used a gas sensor coding ,no error occurred ,but how can my nodemcu is working or not.

Post your sketch (correctly formatted with triple backticks) and tell us what baud rate you have selected in your serial monitor.


Sir problem identified ,forget to change the baude rate in code ,used 115200 baud in serial more doubt ,what is ssid and password.can I give some random characters to this field

Now serial monitor is working.displaying analog values continuously .

But even now blynk app is showing board is not online.what may be the problem?.sorry for not providing the coding part coz it’s too long to type.

SSID is the name of the WiFi network that you are trying to connect to, and password is the password for that WiFi network.

You can put whatever you like in there, but it wont connect to your WiFi without the correct credentials!

I have no idea what “analog values” means. If you are using a NodeMCU then I’d suggest using 74880 as the baud rate in your sketch and in your serial monitor, as this is the native baud rate of most NodeMCU boards and will allow you to see the boot messages from the board as well as your debug messages from your sketch.

Have you never heard of copying and pasting?


 #include <ESP8266WiFi.h>
 #include <BlynkSimpleEsp8266.h>
 char auth[] = "Your auth token"; 
char ssid[] = "your wifi SSID";
mchar pass[] = "your password";
 int buzzer = D2; 
int smokeA0 = A0;
int sensorThres = 600; 
void setup() 
pinMode(buzzer, OUTPUT); 
 pinMode(smokeA0, INPUT);
void loop() 
int analogSensor = analogRead(smokeA0); Serial.print("Pin A0: "); Serial.println(analogSensor); 
 if (analogSensor > sensorThres) 
     tone(buzzer, 1000, 200); 
      Blynk.notify("Alert: Fire in the House");  

Sir did you mean wifi’s hotspot credentials(ssid and password).I am using mobile phone only.
One more doubt,is it necessary to turn hotspot ON in mobile while using blynk app?..pls reply to this question sir

Please edit your post, using the pencil icon at the bottom, and add triple backticks at the beginning and end of your code so that it displays correctly.
Triple backticks look like this:


It’s one set of triple backticks before the first line of your sketch (on a line of its own) and another set of triple backticks after the last line of your sketch (also on a line of its own).
That is two sets of triple backticks in total for the whole of your sketch.

Please try again.


Do you have WiFi in the location where the smoke detector is located?


No sir.only having mobile phone ,I am doing for my final year projects

In that case, the project is of no useful value, as it will only work when your NodeMCU is in range of your phone’s WiFi hotspot.

In addition, you should NOT run this code on your NodeMCU. It breaks the basic rules of Blynk, and will attempt to send a notification every 10th of a second, which is not acceptable.

Read this:

and the documentation for the Notify widget…


Sir nodemcu is warming up slightly in the WiFi chip section ,Everytime when I connect it with my laptop ,is it a problem?

Not a problem provided it’s not uncomfortably hot to the touch.


Sir how to download simpletimer.h library?

You should be using BlynkTimer, which is built-in to the Blynk libraries.


Again it shows as
BlynkTimer.h:no such file or directory