I know there are a bounch of topic about, but almost all of them are related to the version 1.0 of the board ESP-01/01S and they are not suitable for this.
I attached here some images of this board.
As i understood the problem is related to the GPIO0, used to activate the relay but even used to startup ESP8266.
At startup the GPIO0 goes down for few ms and the relay open/close.
I tried to manage this issue by setting in the sketch setup function gpio0 to HIGH but it does not solve the issue:
#define PORT 0
...
void setup(){
pinMode(PORT1, OUTPUT);
digitalWrite(PORT1, HIGH);
...
As via software i have no idea of how to solve, i was thinking to add a capacitor of 220uf or 440uf on the line of GPIO0 so it will remain UP for few ms even if it goes down (just like a little UPS) but i don't know if it could work, what do you think?
Is there another simpler solution maybe via software? The sketch is written in Arduino IDE.
Thank you in advance.