What steps will reproduce the problem? 1.test the "Blink" script for tiny25, Blink's pin is No.4. 2.compile is ok. 3.and upload fail! list the follow message: avrdude: please define PAGEL and BS2 ...

This feature enables your device to enter bootloader mode when a CDC ACM port is opened at 1200 baud rate. This is compatible with the Arduino bootloader trigger mechanism used by many tools like ...