NeoPixel Timing Requirements

[mr. bill]

Are the timing requirements for NeoPixels so close that Arduino compatible boards (Like the Boarduino) that use resonators rather than crystals may not be accurate enough?

The reason I ask is that I have a board that uses a resonator that causes the NeoPixels to flicker during use. When I disconnect the signal line while the program is running and the NeoPixels are left in their last state and the flickering stops. When I use my Arduino Duemilanove I have no flickering. Both boards are running the same code.

[pburgess]

Hmm! The timing spec does allow for a little bit of 'slop' in either direction, and I would think a resonator would be plenty accurate in that regard.

Wonder if it might be something else. Do you have a common ground connection and all of that?

[mr. bill]

I do have a common ground between the strip and for each of the boards. I'll borrow my friends Uno and see how it responds. Unfortunately I don't have access to another resonator based board to compare with.

[mr. bill]

I stumbled across a solution to my flicker problem.

I accidentally touched a bare portion of the signal wire that I had soldered a jumper wire and the flicker stopped. My signal wire in my application had to be over three feet long and was acting like antenna. It was picking up noise and interfering with the signal. I replaced it with a ground shielded wire and the flicker problems stopped.

Hope this helps someone before they pull their hair out!

[helium]

So a resonator is accurate enough to properly control NeoPixels? What is the frequency of your resonator?

[mr. bill]

So a resonator is accurate enough to properly control NeoPixels? What is the frequency of your resonator?

It's 16 Mhz and it's been working perfectly.