WS2801: Support for WS2801 LEDs using SW SPI and HW SPI

[akrto]

Since none of the existing LED drivers worked properly with WS2801 LED modules this driver was added.
Tested on Arduino Uno
Will not pass all regression tests due to dict files being outdated on gh.

[KevinOConnor]

Thanks. I'm not very familiar with this LED type. How does it differ from the existing "dotstar" module?

-Kevin

[akrto]

Thanks. I'm not very familiar with this LED type. How does it differ from the existing "dotstar" module?

-Kevin

In short, the protocols are different :-)

The Dotstars (APA102) has framing built into the protocol, meaning that it is not affected by pauses in the data that would be caused by the entire data not fitting into one message from Host to MCU-board running the LEDs.
There is about 40 bytes of data in each message right?
APA102 also has global dimming, which is something that the WS2801 doesn´t.

The WS2801 relies on pauses between messages for framing, meaning that if not all data could fit into one message from host to MCU it would start all over with the data in the next message.
Because of that, I had to implement local LED-registry on the MCU-board, a´ la Neopixel style.

Thank you for all the hard work you guys put into this project, you guys rock!

Framing/protocol for Dotstars/APA102:

Framing/protocols for WS2801:

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