user1100: I would like to have an array of eight 7- and 8-segment LED numerical displays on my Adafruit Trinket.
I know that there are some prebuilt arrays of 4 LED's. So 2 in array would do just fine.
However, my Adafruit Trinket doesn't have enough ports for that. I have heard something about connecting it to a small piece of controlling hardware that makes me able to have way less ports in need.
What is the appropriate way of connecting a lot of those LED's on only a few ports on a micro controller?
My ideal output would be as follow: 
88 88:88:88 or maybe 88 88.88.88
So ideally there would be a small space between the first group of 2 digits and the rest.
Basically, the last 6 digits will represent a time in minutes, seconds and hundreds of seconds.

user84: For LED displays, I advise using a MAX7219.
This circuit:

can manage up to 8 digits (7-segments + 1 LED for DP or colon separator) or up to 64 LEDs
needs only 3 pins to manage display
can be daisy-chained if you need to interface with more than 64 LEDs
requires only 1 resistor to be fully functional
is easily supported on Arduino with this library

I have used it in several circuits and happy with it.
Note that there also other libraries that support this circuit but I haven't used them.
This circuit has only one downside: its price (about $10 each); but the price is counter-balanced by its simplicity and the fact you don't need any additional component (e.g. transistors) besides a simple resistor.

1100: <p>I would like to have an array of eight 7- and <a href="http://4.bp.blogspot.com/-d4ug4mb_Cw0/T6y7ZVrbb-I/AAAAAAAAAsE/nj6Tfp0j26s/s400/SEV1.jpg" rel="nofollow">8-segment LED</a> numerical displays on my Adafruit Trinket.
I know that there are some prebuilt arrays of 4 LED's. So 2 in array would do just fine.
However, my Adafruit Trinket doesn't have enough ports for that. I have heard something about connecting it to a small piece of controlling hardware that makes me able to have way less ports in need.
What is the appropriate way of connecting a lot of those LED's on only a few ports on a micro controller?</p>

<p>My ideal output would be as follow: 
88 88:88:88 or maybe 88 88.88.88
So ideally there would be a small space between the first group of 2 digits and the rest.
Basically, the last 6 digits will represent a time in minutes, seconds and hundreds of seconds.</p>
 84: <p>For LED displays, I advise using a <a href="http://datasheets.maximintegrated.com/en/ds/MAX7219-MAX7221.pdf" rel="nofollow">MAX7219</a>.</p>

<p>This circuit:</p>

<ul>
<li>can manage up to 8 digits (7-segments + 1 LED for DP or colon separator) or up to 64 LEDs</li>
<li>needs only 3 pins to manage display</li>
<li>can be daisy-chained if you need to interface with more than 64 LEDs</li>
<li>requires only 1 resistor to be fully functional</li>
<li>is easily supported on Arduino with <a href="http://playground.arduino.cc/uploads/Main/LedControl.zip" rel="nofollow">this library</a></li>
</ul>

<p>I have used it in several circuits and happy with it.</p>

<p>Note that there also <a href="http://playground.arduino.cc/Main/LEDMatrix" rel="nofollow">other libraries</a> that support this circuit but I haven't used them.</p>

<p>This circuit has only one downside: its price (about $10 each); but the price is counter-balanced by its simplicity and the fact you don't need any additional component (e.g. transistors) besides a simple resistor.</p>
