I am trying to use C3 and RX both as interrupt pins. They are not on the same interrupt group. Sadly this is not working when I trigger C3. Here is the code to reproduce:
@lympik, it is not a good idea to put Serial.print() in an ISR. Instead, change the state of the D7 LED to indicate an interrupt have been triggered. Or, set a flag in each ISR and test/reset the flags in ‘loop()’ where you can use Serial.print().