circuit diagram for 8*8 LED Matrix

Hello,

for a school project I am going to build 4 8*8 LED matricen. I will connect each matrix so, that it only uses 3 pins of the arduino by using the 74HC595 shift register.
I designed a circuit diagramm(atached) and I got some questions about it.

Does it work like this?

So can I controll every LED in that Matrix seperatly?

To what shall I connect the ground pin?

Is it just connection to the earth?

To what shall I connect the Vcc pin( the one which goes to 5V)?

Do I get the power from my Arduino itsself or do I need an external power supply?

Having row and column drivers will allow you to control one row at a time. You will need to repeatedly scan through the rows to control each LED separately.

If the number of LED's lit at once draws more than 400 mA you will need to use an external power supply. If each LED draws 20 mA and you light at most 8 at a time (one row) you can use the Arduino +5 line to supply the 160 mA.

Ground should connect to Arduino ground. If you use a separate power supply for the LED's it should ALSO connect to power ground.

You should probably NOT use D0 and D1 for your data pins. Those double as the serial port and would prevent Serial.print() from working. Use D2, D3 and D4.

A 74hc595 output is only good for sinking/sourcing 6-8mA. It should not be used to source a whole row or sink a whole column. Its outputs can be used to control other devices, such as ULN2803 as a current sink (connected to cathodes) and UDN2981 as a current source (connected to anodes).

Okay thanks so far.

CrossRoads: A 74hc595 output is only good for sinking/sourcing 6-8mA. It should not be used to source a whole row or sink a whole column. Its outputs can be used to control other devices, such as ULN2803 as a current sink (connected to cathodes) and UDN2981 as a current source (connected to anodes).

It should be working as 6mA per LED should be enough as the LEDs don't need to be very bright.

When using this design for an LED Matrix http://tronixstuff.files.wordpress.com/2010/07/matrixschematic2.jpg

Why do need some capacitors.

And the ground will be connected with the ground from Arduino? And to what shall I connect the 5 Volt? How can I calculate the value of the resistor?

“It should be working as 6mA per LED should be enough as the LEDs don’t need to be very bright.”
There you go - 6mA per LED. If one whole is on, or one whole column is on, then you need 6 x 8 = 48mA.

The 7219 has internal current control. Read the datasheet, it tells you the Resistor value to use for the desired current & LED used in Table 11.

Capacitors allow for power supply buffering for the mini current surges that can take place during operation.

Ground must be connected to arduino ground.

5V can be the regulated 5V from the arduino, the '7219 should not need more than ~330 mA (again from datasheet) if you are sinking a Lot of current per LED.
I am thinking probably more like (8 LEDs on x 20mA/LED) + say 10mA for the logic in the part, ~170mA.