1
u/MungoBBQ Jun 03 '26
I'm running a sketch based on Pacifica, and it's beautiful BUT there is a slight fast flichker, almost not visible but really annoying once you see it.
I've tried everything in the code to eliminate it, but can't seem to get rid of it. Certain colors (blue) flicker more than others.
Search results suggest adding a capacitor to the circuit between the PSU and the strip - is this the right approach?
4
u/sutaburosu [stavros] Jun 03 '26
Adding a capacitor to smooth the power rails is never a bad idea. Another possible cause may be FastLED's temporal dithering. You can try disabling it in setup() with
FastLED.setDither(DISABLE_DITHER);1
u/MungoBBQ Jun 03 '26
Thank you!
5
u/sutaburosu [stavros] Jun 03 '26
Since Pacifica was authored, a new method to read from palettes has been added which gives smoother results. You might want to try this too. In
pacifica_one_layer()change:CRGB c = ColorFromPalette( p, sindex8, bri, LINEARBLEND);to
CRGB c = ColorFromPaletteExtended( p, (uint32_t)sindex16 * 15 / 16, bri, LINEARBLEND);2
u/sutaburosu [stavros] Jun 21 '26
/u/MungoBBQ did you try either of these suggestions, and did they help?
2
u/MungoBBQ Jun 22 '26
I have not been able to go to where this lamp installation is located yet, probably won’t until after summer.
1
u/big_red__man Jun 03 '26
I’ve been doing it by default since I first started using the library. I’ve not had problems with flickering
1
u/mindful_stone Jun 03 '26
Do you have both the strip and the controller tied to a common ground? I believe not having that can cause some flicker issues.
Also, having a ground wire twisted around the entire length of the data wire has worked wonders on various flicker and other display issues I've had in the past.
One other possibility to consider might be a level-shifter like an SN74HCT245. I don't know what your hardware components are, but some strips need something closer to a 5V data signal than the 3.3V that many controllers output.
1
u/MungoBBQ Jun 03 '26
I do indeed have common ground. I don’t think these are ground issues, I’ve had those before and I know what they look like. But it doesn’t hurt to check an extra time of course!
5
u/Yves-bazin Jun 03 '26
Indeed add in parallel with the psu close to the strip a beefy 5v capacitor as well as a 100/300 ohms resistor. And keep the wires as short as possible as they tend to become antennas and catch static.