After changing rx(to 16) and tx(to 17) I don't see any outputs from arduino in serial monitor. I also found out, that in if (Serial1.available() > 0) { Serial1.available() is never greater than 0 (I put Serial.print in next line).
After changing rx(to 16) and tx(to 17) I don't see any outputs from arduino in serial monitor. I also found out, that in if (Serial1.available() > 0) { Serial1.available() is never greater than 0 (I put Serial.print in next line).