is the "tmp_bt" reset somewhere?
are you sure that the incoming characters has no '\r' and-or '\n'?
are you sure that the "tmp_bt" and the singles chars in the end String has the same case?
did you try to print the incomings chars?

thanks for the info...

hi...have you tried a simple:

if(MySerial1.available()){
byte a = MySerial1.read();
Serial.print(a);
}

Hi girasera, In the past I have had similar problem; I have search in the net for some cause/solution...at the end I found that the ESP32 "close" the transimition too fast....but also, using a signal analizer, I found that the quality of the data exchange was not good...so i tried the MAX3485 module...

Dears All, In my next project I need to have a communication between a "master" and some "slaves" and I am thinking to use the ESP32-NOW protocol. one of the steps that I want to implement is a "is still alive" check. If not I want/need to remove the peer node from the list...but how the deleting wo...