mga sir..i need help with my project which is a lighting LED matrix that scrolls from right or left or marquee..the project requires me to use a port pin interface through the sereal port....i know this is most very difficult and normelly onlt the profesionells can do...but i need it.....all you must help.
Hey there, uh, tahm. I presume you mean the RS-232 serial port on your PC. In which case, find the pinout for the RS-232 port (google it) and you may discover that the pins will connect directly to a shift registers as the 74198:
pdf1.alldatasheet.com/.../74198.html
Hint: put one 74198 in parallel to 8 rows of 74198s and use the parallel outputs to feel the serial inputs of the rows of 74198s and use the third bit of a 4 bit counter chip to clock the inputs of the rows of 74198s.
This way you will only have to work out the LED current limiting resistors, bit timing, and a way to feed the rows of shift registers from both "ends" of the series. (eight rows of, say, 16 such registers gives you an 8 by 128 matrix to illuminate.)
Or you can use a microcontroller (if your prof. allows it):
www.instructables.com/.../