[sdiy] Coloured LEDs

[rsdio at audiobanshee.com]

On Feb 20, 2017, at 12:41 PM, "Byron G. Jacquot" <thescum at surfree.com> wrote:
>> So this NRZ signal can be generated with a SPI port? How is this done?
> 
> By clocking at 8X the bit rate, and turning each bit of output into a byte that's shaped like the expected code, such as 0b11000000 and 0b11111000.

You could almost get by with 4X the bit rate, but that just barely falls within the +/-150 ns window. 5X would be almost dead on, at least as good as 8X, but more difficult to calculate the code translation.

Meanwhile, my quick scan of the data sheet leaves me with the impression that this chip must be fed data constantly or it will be reset. I suppose you could leave the data line high to avoid reset. If it must be fed constantly, then that's an even greater load on the CPU.

Must be a really cheap part for people to put up with the strange communications.

Brian