This repository contains some C++ utility libraries for AVR microcontrollers, as well as a few projects using these libraries.

In particular, it contains the following generic library code:

• USB utility code for building USB devices.

• A debug logging framework, and a USB debug interface compatible with PJRC's hid_listen program

  This debug interface also supports SET_REPORT calls to reboot the device.

• A generic keyboard controller implementation, along with a USB keyboard interface.

• A bit-banging I2C implementation, as well as some basic code for interacting with an 24c08 EEPROM over an I2C bus. This can be used for performing I2C communication over generic I/O pins rather than than the hardware-supported pins.

This repository also contains full keyboard controller implementations for two different physical keyboard schematics that I currently have. (These are for two different generations of Maltron dual-handed keyboards, where I replaced the factory controller with my own implementation.)

I have been primarily been developing these projects using the Teensy 2.0++ USB board from PJRC.

PJRC's example keyboard and debug interface implementations were very useful when helping to build my own implementations. (I decided to build my own implementations in C++ partially as a learning project, and also partially so I could have some more re-usable code that could be shared across multiple projects.)

The src/pjrc directory does contain some code taken directly from the PRJC site, and includes PJRC license information.