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jgarff / rpi_ws281x

Userspace Raspberry Pi PWM library for WS281X LEDs
BSD 2-Clause "Simplified" License
1.77k stars 622 forks source link

Huge voltage drop and RGBW issue #230

Closed resetscoder closed 6 years ago

resetscoder commented 6 years ago

Hi ! I've just bought an Sk6812 rgbw in order to build a sunrise alarm clock with a Raspberry Pi B. The led strip is 5m with 60led/m, so that I have a 20A/5V power supply (60mA per led). But I'm facing with some issues while using the white led ! More than half of the strip suffer from a Red shift and intensity of white is lowering to zero when I try to go from color(0,0,0,0) to color (255,255,255,255). Even if I plug the power from the two side of the strip it suffer the same in the center.

My wiring is done with breadboard, May it have an impact on the drop of voltage ?

Is someone facing the same issue ? It seems to work better with SK6812_lowlevel.py (no lowering of Rgb (without white)), so I wonder if it may come from the rpi _ws281x ?

penfold42 commented 6 years ago

Breadboard wire is terrible for power connections.

Both the power and ground wires need to be good size cables. Mains wiring has to carry 10+ amps - look how much thicker the conductors are.

resetscoder commented 6 years ago

Thanks for the tips ! I will make the setup with some good wires !