On some cases the receiver could not work when the esp8266 is powered by Vin instead of the usb plug of a nodemcu with serial monitor

More details here:
https://community.home-assistant.io/t/how-to-make-use-of-generic-433mhz-sensors/1215/47
http://www.esp8266.com/viewtopic.php?f=32&t=11492

_433toMQTTto433_ESP8266.ino

@@ -99,7 +99,7 @@ void setup()
   
   mySwitch.enableTransmit(4); // RF Transmitter is connected to Pin D2 
   mySwitch.setRepeatTransmit(20); //increase transmit repeat to avoid lost of rf sendings
-  mySwitch.enableReceive(0);  // Receiver on pin D3
+  mySwitch.enableReceive(5);  // Receiver on pin D1
 }
 
 void setup_wifi() {