Many smaller projects written by Jeremy Cole on Atmel AVR MCUs:

• uart -- A UART (serial) library based on Peter Fleury's uartlibrary. Also see uart_test.
• i2c -- An I2C (aka TWI) library initially based on Peter Fleury's i2cmaster. Now includes slave mode support using callback functions. Also see i2c_master_test and i2c_slave_test.
• rtc -- A custom real-time clock (RTC) library currently supporting the Maxim's DS1307 I2C-connected RTC chip. The rtc library requires the i2c library above. Also see rtc_test.
• lcd -- An LCD library supporting both 8-bit and 4-bit parallel modes of the HD44780U LCD controller. Also see lcd_test.
• led_charlieplex -- A custom library for generically describing the structure of and controlling a charlieplexed LED matrix.
• led_sequencer -- A custom library for time-sequencing LED animations, supporting the led_charlieplex library for describing the LED matrix to play animations on.
• nmea -- An NMEA sentence parser for interoperation with GPS devices. Currently only supports $GPRMC sentences.

Larger specific projects:

• led_analog_clock -- The complete set of code using the uart (for debugging and setting the time), i2c, rtc, led_charlieplex, and led_sequencer libraries. Can connect to the lcd_i2c_digital_clock via I2C interface.
• lcd_i2c_digital_clock -- An LCD-based digital clock module that attaches to led_analog_clock via I2C interface and displays the time in digital form.
• gps_i2c -- A translator from UART to I2C to allow a GPS to be attached to the led_analog_clock project to provide an accurate time sync source.