And I don`t know how to use it. It has the following pins:
GND, DATA, LATCH, SCK (i think this is the clock) and VCC.
I know how to wire it up to the Arduino, but i don`t know how to make it display something using Serial Monitor. I assume that there must be a library of letters, something like this:
EDIT: Sorry, that sketch is not going to run on an Arduino. Not without expert adaptations.
But it should certainly be possible to use the matrix with an Arduino. You may have to write your own sketch.
The schematic on Olimex's website shows it contains 2 74xx595 shift registers and a uln2803 attached to one of them to boost its current sinking capabilities.
If you can't find a sketch for it I can help you write a simple one, although you will have to test the sketch because I don't have a display like yours.
Xeyow:
So my father gave me this 8x8 led matrix...
Oh dear! No wonder he didn't want it! It's a right pain to operate - you have to write code to perform the multiplexing continuously.
It's a demonstration "toy". Much more convenient and practical are the (quite cheap) ones which use a proper MAX7219 driver - a single IC which is designed for the purpose and performs all the multiplexing, current control and brightness control (of the whole display) for you in a single chip with just one resistor (and bypass capacitors).
(When I say "much cheaper", I refer to the Chinese knock-offs - which do work. Presumably Olimex figured the HC595s and ULN were cheaper - which may be correct, but at the substantial expense of functionality.)
Yes, that is the secret of multiplexing. It looks like all the rows are lit at once but in reality only one row at a time is lit. Its just too fast to see.
The Arduino is doing the multiplexing. Every 2 milliseconds it sends out a row of data to the display. The same 8 rows must be sent over and over.
The max7219 chip that Paul__B was talking about is often used for 8x8 matrices. Its more sophisticated than the basic chips on your display. It does the multiplexing itself. The Arduino only has to send the data once each time the display changes. The chip then does the multiplexing, leaving the Arduino free to do other things.
However, the Arduino is pretty fast and can multiplex a display with basic chips and still do quite a lot of other things at the same time.
You asked about what the clock and latch connections do. Have a look at this to see if it helps you understand: