How to Install an ATtiny Bootloader With Virtual USB
Contributors:
Shawn Hymel
Shawn Hymel 
Resources and Going Further
While this is a lot of information to take in, it shows how to hack the Arduino IDE to load custom board definitions. These steps should work for other ATtiny devices that are supported by the micronucleus project, such as:
You might have to modify the pins_arduino.h file, however, if you plan to use a different ATtiny.
ATtiny84 Pinout
If you need additional support, please check out the following resources.
If you want to go further with the ATtiny, please check out our additional tutorials that showcase the ATtiny:
Hack Your Roshamglo Badge
Learn how to customize and program your Roshamglo badge.
Roshamglo Hookup Guide
This tutorial provides everything you need to know to get started with the Roshamglo badge.
Atto84 Hookup Guide
A bare minimum Arduino compatible breakout using a ATtiny84 for integration into your small projects!
Qwiic Single Relay Hookup Guide
Get started switching those higher power loads around with the Qwiic Single Relay.