ATtiny+ws2801 with Arduino library?

Projects General Guidance
21

pylon:
The Adafruit library for WS2801 does not use anything except SPI. But if you define your own two pins to use it circumvents the hardware SPI and does all the necessary stuff itself.

The Adafruit WS2801 library can either use hardware SPI or it can bitbang.

I just got some attiny85s myself, and I have a ws2801, so I'm interested in if someone solves this.

Which attiny85 library are you using Ragnar?

Are you using arduino-tiny:
http://code.google.com/p/arduino-tiny/

or the MIT one:
http://hlt.media.mit.edu/?p=1229

22

@jfenwick: Your right, the library can use both modes but it includes "SPI.h" (which does not compile in ATtiny mode) and uses some SPI registers in the code directly that are not defined for ATtiny.

Using the library modifications I mentioned the Adafruit library should compile and work on the ATtiny, but without hardware support.

23

I cleaned up Adafruit ws2801 library from SPI stuff and got it compiled and uploaded.
I had to make some changes to ArduinoISP to get it work with attiny.
I don't remember, which attiny library I use. I tried few of them. I have folder Arduino/hardware/attiny and there is 'boards.txt' and folder 'variants'.
Boards.txt includes attiny 45, 85, 44, 84 with different clock speeds.
Now I just wait for ws2801 to arrive and see if it works.

24

It just so happens I'm messing with the WS2801's bigger brother the WS2803 as I type and the most simple example code I found was from sparkfun (http://www.sparkfun.com/datasheets/Components/LED/LED_Strip_Example.pde)

25

It works!
I made a fast demo setup.
Changes colors with pushbutton.
Blackout, red, green, cyan, magenta, yellow, orange, white, rainbow, blackout.

26

are you the same ragnar who made the morseEnDecoder?

27

spruce_m00se:
are you the same ragnar who made the morseEnDecoder?

No.

28

Hi, I'm very interested in this topic. I have several ws2801's and lpd6803 that I use for all kinds of things. Tomorrow a ATTiny85 is arriving in the mail and I will be trying to compile my sketches. For the lpd6803 I use non-spi code (digitalWrite()) to drive the leds and I was researching ways to drive the ws2801.

Would you like to share your modified library and an example sketch?

In return I have a nice stairway light sketch for you if you ever want to put leds in your stairway and activate them w/ PIR's.

Hope to hear,

Fex