The morse code tie tack is a device which use led to trasmit morse code messages.
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment.
Each character (letter or numeral) is represented by a unique sequence of dots and dashes.
The morse code is a variable length code, but the max length of a character is 5 dots or dashes.
The device is built on ATTiny13 micro.
This is a simple to build device, i've used the firse time to transmit a xmas message, then i've used in some party with friends :)
My morse code implementation is based upon the Ethan Blanton idea (http://kb8ojh.net/msp430/morse_encoding.html). Any character can be rapresented in 8bit using 0 as padding bit, 1 for the start bit, remaining bit for the morse code character (0 for dit[.] 1 for dah[-]).
I've extended the morse code using two led, one for printing dit or dah, the other for letter, word and string space.
There is also a button to select the string to emit.
Strings to show are stored in Attiny EEprom.
Schematics is attached, is very simple, need only some resistences and two led, and it work with any 3v battery, like cr2032.
Source code available here: avr_morse_led_1.1.zip