KirAsh4:
Read the data sheet on the WS2801. It tells you when/where you need to add the resistors.However, I have run the FastSPI testled sketch on a full 5m reel straight out of the box with no problems what so ever. The only change I made to the sketch was to add the proper dataRate line, which is missing from the sketch. No resistors added, just hook up the four wires, make sure the 4 wires at the end aren't touching anything metal, and turn it on. In fact, I just grabbed two reels, hooked them up in parallel to my Uno, using FastSPI. I only ran one sequence, which is the single color down the whole strip, because it's not hooked up to a high amp power supply:
(the freezing that you're seeing, if any, is just the way YouTube processed the video - the chase is smooth with no hiccups.)
- YouTube
Thanks for posting this up. I looked in the spec sheet and it only states what's below. I changed the pull up resistors from 10K to 50 with no positive effect.
The Connection and Driving of Cascading Operation
The transmit the data over long distance by cascading, the WS2801 integrates push-pull output stage with strong driving capability which enables the data and clock can be transmitted up to 6 meters at 2MHz clock frequency.
To prevent the reflection, it is necessary to connect a 50? resistor at the data input or output port for impedance match.
Any thoughts on what the problem could be? A bad/faulty strip? This wouldn't surprise me because the quality does not look top notch...
This afternoon I will try swapping out to a spare arduino to see if that changes anything.