ATtiny with USB Boot Loader: Tips & Tricks for DIYers DIYers building a development board similar to this one, and looking for applications to be added through USB without an external programmer, ...

We included the ATTiny85 chip with an on-board USB programmer which simply plugs into the learning kit making it easy to make connections and prototype your projects.

It’s called Micronucleus and it turns the lowly ATtiny 85 into a chip with a USB interface capable of being upgraded via a ‘viral’ uploader program.

For USB serial programming, GGtag uses the Web Serial API through the web interface at ggtag.io. The device can emulate 125 kHz RFID tags through an ATtiny85 MCU and the avrfid firmware.

His hardware board is exceedingly simple, just an ATtiny 2313, a USB port, and a handful of other components, but allows [Ben] to receive data on eight pins on a breadboard and send them over USB ...