I have several Arduino Leonardos connected to a Raspberry Pi (running Ubuntu) via USB. They all appear underas /dev/ttyACM0, /dev/ttyACM1, etc.
Occasionally, one will disappear and even pressing the Arduino's reset button won't bring it back. Is there any way to "refresh" or "reinitialize" the ttyACM* devices to make them reappear without having to reboot the Raspberry Pi?