Blynk Shield disconnects need assistance

Hi Everybody
have set up a Blynk shield with the Esp-01 and the Uno Pro Mini and it works fine stays connected to the Blynk server until I remove the FTDI USB programmer from the Pro Mini it then disconnects from the Blynk server, putting it back again it reconnects.
Cand someone please help.
Here is the sketch I am using

#define BLYNK_PRINT Serial

#include <ESP8266_Lib.h>
#include <BlynkSimpleShieldEsp8266.h>
char auth[] = "";
// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "";
char pass[] = "";

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

// or Software Serial on Uno, Nano...
#include <SoftwareSerial.h>
SoftwareSerial EspSerial(2, 3); // RX, TX

// Your ESP8266 baud rate:
#define ESP8266_BAUD 9600

ESP8266 wifi(&EspSerial);

void setup()
  // Debug console


  // Set ESP8266 baud rate

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

void loop()

Looking at a pin out diagram for the Pro Mini, it seems that pins 2 and 3 are connected to the hardware serial port, and you’re trying to use the same pins for your software serial port.
I’m surprised that this works at all.

Change your software serial pins to something else, and connect the ESP-01 to the pins that you choose to use.


Actually, if it is a true Pro Mini, then 0 & 1 are the Serial pins, also duplicated on the FTDI header, 2 & 3 should be fine for SoftSerial.


@doart If all works when the FTDI is connected, then I suspect a power issue… perhaps whatever you are using, when NOT using the FTDI, simply cannot handle the needed current for both the Arduino and the ESP-01.

Hmmm, I looked at this…

and assumed that the grey numbers were PIN numbers - my bad!


Hah… I saw many different pinout diagrams as well, including that one (no idea what the grey referred too) … but I cheated and looked at the silkscreen labels :stuck_out_tongue:

I have had a good look at this again however I tried various pin combinations 4&5, 6&7 also 10&11 but I sit with the same situation that it stays connected with the FTDI connected but disconnects when removed.
Power supply is not the problem running the system on a 5Vdc 2 Amp power supply with 3.3Vdc regulator for the ESP-01 TX & RX signals are routed through a Logic converter now I am really stumped.
I also put a 5v on the Vcc pin plus ground on GND pin of the Pro Mini programming pins it still stays off line leaving me thinking that the DTR pin may have something to do with it but I don’t what if anything.

I did a bit more testing and got it to stay on line by pulling the DTR to GND and putting a 5v + GND on the appropriate programming pins on the Pro Mini.

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