benlaurie/arduino-- — pull request #4 by larsimmisch (2013-04-24 19:32:38+00:00)
Title: Max7219, quad encoder, better modularity w.r.t. clock ISRs

Hi Ben,

this adds:

* support for the Max7219 (good for 8x8 LED matrices)
* support for Quadrature encoders
* better modularity for clock ISRs

The clock ISR modularity thingy works like this: if you `#define CLOCK_NO_ISR` before including the clock header, you write the ISR yourself, but get to reuse the clock16 ISR.

With the quad encoder, I've used it like this:

```
#define CLOCK_NO_ISR
#include
#include

typedef _Quadrature Quadrature;

ISR(TIMER0_OVF_vect)
{
Quadrature::update();
clock16_isr();
}
```

Oh yeah, we need a quad encoder example in arduino--.