Objective Development Forums

Perhaps, make the AVR device a keyboard and generate a special button combination (hotkey) at your desired temperature, this can be used to generate an interrupt then the PC side software can read the temperature from the AVR using feature reports then make your popup. This avoids polling, although ...

I don't know if this helps but there are 2 tables I found for boot compliant keyboards. This first code is a table I've seen used on the PIC18F based USB keyboard but should also be useful AVR-USB. 0x05, 0x01, // Usage Page (Generic Desktop), 0x09, 0x06, // Usage (Keyboard), 0xA1, 0x...