How to connect esp12F directly to WiFi without the need of opening serial monitor

I’m trying to make direct contact with WiFi for my esp12F without the need of opening the serial monitor, but no luck with that. I’ll really appreciate it if you could help.

This the code I’m using

#define BLYNK_PRINT Serial // Comment this out to disable prints and save space
#include <SPI.h>;
#include <ESP8266WiFi.h>;
#include <BlynkSimpleEsp8266.h>;
#include <SimpleTimer.h>;
#include <DHT.h>;

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

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

#define DHTPIN 2 // What digital pin we're connected to

// Uncomment whatever type you're using!
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT22 // DHT 22, AM2302, AM2321
//#define DHTTYPE DHT21 // DHT 21, AM2301

SimpleTimer timer;

// This function sends Arduino's up time every second to Virtual Pin (5, 6, 7 &amp;amp;amp;amp;amp;amp; 8).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void sendSensor()
 float h = dht.readHumidity();
 float t = dht.readTemperature(); // or dht.readTemperature(true) for Fahrenheit

 if (isnan(h) || isnan(t)) {
 Serial.println("Failed to read from DHT sensor!");
 // You can send any value at any time.
 // Please don't send more that 10 values per second.
 Blynk.virtualWrite(V5, h); // Humidity for gauge
 Blynk.virtualWrite(V6, t); // Temperature for gauge
 Blynk.virtualWrite(V7, h); // Humidity for graph
 Blynk.virtualWrite(V8, t); // Temperature for graph

void setup()
 Serial.begin(115200); // See the connection status in Serial Monitor
 Blynk.begin(auth, ssid, pass);


 // Setup a function to be called every second
 timer.setInterval(1000L, sendSensor);

void loop()
{; // Initiates Blynk; // Initiates SimpleTimer

It’s not necessary for the serial monitor to be open, or to have the ESP8266 connected to a computer, for it to connect to WiFi.

Are you using a bare ESP12F chip, or is it a NodeMCU that has an ESP12F chip mounted on it?

What symptoms are you seeing when the board/chip is powered-up without the serial monitor open, and what serial messages do you see when the serial monitor is open?


I tried to let it connect with Blynk without opening the serial monitor but with no success, I had to open it in order to have a successful connection.

I’m using an esp12F chip

when powering the chip the light blinks for about 5 seconds and then stops. This is the message I’m getting in the serial monitor

Do you have any pull-up resistors on EN and GPIO0?


This is my connection

I’m guessing that your DTR and RTS pins are being energised when the serial monitor is opened, but not when it’s closed.
Either way, it’s specific to your particular hardware, and not a Blynk related issue.
Maybe one for a more hardware specific forum?


I actually use this connection for flashing the firmware, but when I connect it to arduino RTS and DTR are not connected to anything