I have an ESP-01s that I want to use as a shield so my Arduino Uno project could communicate with my Blynk app through wi-fi. I used this video as reference.

This is the sketch. It is just the ESP8266_Shield example from the Blynk library.

#define BLYNK_PRINT Serial

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

char auth[] = "-------";

char ssid[] = "-------";
char pass[] = "-------";

#include <SoftwareSerial.h>
SoftwareSerial EspSerial(2,3); // RX, TX

// Your ESP8266 baud rate:
#define ESP8266_BAUD 115200

ESP8266 wifi(&EspSerial);

void setup()
  // Debug console


  // Set ESP8266 baud rate

  Blynk.begin(auth, wifi, ssid, pass);

void loop()

This is the schematic: enter image description here

What happens:

  1. The moment the Arduino is connected, the Blue LED flashes for a split second then all LEDs will remain off. No red led, no blue led, really just off.
  2. The ESP-01s becomes very hot to the touch
  3. Tried speaking to the ESP-01s through the Serial Monitor with BareMinimum example @115200 baud rate (Many Sources say that this is the default baud rate of the recent boards) however no response whatsoever.
  4. Running the code above will get this error: enter image description here

What I've done:

  1. Tried using the HW-131 Breadboard Power Supply to supply the 3.3V (Common GND with Arduin) of the ESP-01s because I read that the ESP-01 could need more current than the Arduino Uno could provide. Still the same effect, no LEDs blinking, (even more) hot to touch, not responding to AT commands.
  2. Attempted to follow a video on how to flash the ESP-01s but when I tried to run the flasher, it could not communicate with the ESP-01s.
  3. Switching Rx Tx ESP-01s but no luck.
  4. Added a 10k ohm resistor from 3.3V to the Vcc and EN pins of the ESP-01s. Not heating up anymore but still no response.

I really thought this is a power problem but could it be the ESP-01s itself is defective?

This is what the ESP-01s look like enter image description here

  • Overheating = bad. Sounds like it's dead.
    – Majenko
    Mar 1, 2021 at 14:41
  • I don't see a pullup on the ESP's reset line. I doubt that is causing your your heating issue but you may get spontaneous reset issues later.
    – JRobert
    Mar 1, 2021 at 18:29

1 Answer 1


The ESP8266 is (highly likely) dead. The overheating is the giveaway.

Because you haven't mentioned it, please measure the 3.3V coming out of the Arduino with a multimeter. Unlikely to be the issue but it is easy to check.

You will need to buy a new ESP8266 and connect it up and give it a try with a fresh board. If all is good with the new board then the first thing you will notice is that there is no overheating. (If there is overheating, then you need to check your wiring.)

I notice that quite a lot of people add a 10K pull up resistor between the 3.3V line and the Enable pin. It certainly won't hurt to add a 100 ohm resistor between the Tx pin and D2 of the Arduino as a current limiting resistor, just in case.

  • I forgot all about this thread and yes that was the case :( I got a replacement ESP-01s and it worked. Apr 5, 2021 at 13:56

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