I2C and serial interface for HD44780 LCD and more

Power supply: 2.7 to 5.0V
Controller: MCU AVR ATtiny2313V
LCD HD44780 compatible ctrl. upto 2LCDs or LED dot matrix module
Both four keys and four LEDs are available.
Interface: I2C upto 400kHz with clock stretch control ,
and Serial interface 38400Bps 8bit no-parity stop-bit 1.


// *** I2C slave device for ATtiny2313 ***
  .-+- src/
    |   +-- 00start.S   // interrupt vector & startup handler
    |   +-- 10main.S    // main loop
    |   +-- 11usart_proc.S // usart_LCD procedure
    |   +-- 12i2c_proc.S // I2C_LCD procedure
    |   +-- 14ledmatrix.S // I2C_LED dot matrix procedure
    |   +-- 20sub.S     // subroutines
    |   +-- i2c_s.S     // i2c slave handler
    |   +-- CLCD.S      // HD44780 controller with multiplex-bus
    |   +-- SW_LED.S    // Generic multiplex-bus control
    +- inc/
    |   +-- config.inc  // configuration header
    |   +-- common.inc  // generic definitions
    +- obj/
    +- bin/

Fuse configuration: Low=0xe4 High=0xdb Ext=0xff

bin/AVR_I2C_IO.elf usage:
  0 .text         000006c8  00000000  00000000  00000074  2**1
  1 .bss          00000043  00800060  000006c8  0000073c  2**0
  2 .eeprom       0000003e  00810000  00810000  0000073c  2**0

bin/AVR_I2C_IO_LEDdotMatrix.elf usage:
  0 .text         00000758  00000000  00000000  00000074  2**1
  1 .bss          00000043  00800060  00000758  000007cc  2**0
  2 .eeprom       0000003e  00810000  00810000  000007cc  2**0

; more detail refer to http://yesavr.web.fc2.com/tiny2313/AVR_I2C_IO/AVR_I2C_IO.html
