http://digistump.com/wiki/digispark/tutorials/connecting
https://startingelectronics.org/tutorials/arduino/digispark/digispark-linux-setup/
Add udev Rules to the System
sudo vim /etc/udev/rules.d/49-micronucleus.rules
# UDEV Rules for Micronucleus boards including the Digispark.
# This file must be placed at:
#
# /etc/udev/rules.d/49-micronucleus.rules (preferred location)
# or
# /lib/udev/rules.d/49-micronucleus.rules (req'd on some broken systems)
#
# After this file is copied, physically unplug and reconnect the board.
#
SUBSYSTEMS=="usb", ATTRS{idVendor}=="16d0", ATTRS{idProduct}=="0753", MODE:="0666"
KERNEL=="ttyACM*", ATTRS{idVendor}=="16d0", ATTRS{idProduct}=="0753", MODE:="0666", ENV{ID_MM_DEVICE_IGNORE}="1"
#
# If you share your linux system with other users, or just don't like the
# idea of write permission for everybody, you can replace MODE:="0666" with
# OWNER:="yourusername" to create the device owned by you, or with
# GROUP:="somegroupname" and mange access using standard unix groups.
chmod 644 49-micronucleus.rules
sudo udevadm control --reload-rules