Datasheet

Of course, you can use the FTDI cable for debugging not just programming!

To use the FTDI cable to debug programs, add the standard Serial.begin(baudrate); line as you would with an UNO and

Serial.print or Serial.println as you expect! Then select Tools / Serial monitor after loading your program. The Trinket

will re-start when you launch the monitor so you can see your data right from the start; be patient while the Trinket

finishes starting.