Question : I have a roaming red LED on a WS2811 strip

Questions
1

Hi, I have a roaming red LED on a WS2811 strip of 100 LEDs.

I have check the data signal (I use 74HCT125 driver between the D1-Mini and the led strip) and it is within logic level specifications.

Any idea where to look for?

Thank you for your help.

RJM

2

If that is the exact part # of the level shifter used, that’s the problem. It is too slow for your LED strip. I believe the part # you want is 74HCT125N

3

The N just means it’s plastic. :wink:

All grounds connected together?

4

Thank you very much for your answer. I will order some 74AHCT125D (SMD part). The propagation delay is 7 to 9 nanoseconds, while the HCT is only 30 nanoseconds.

The 74HCT125N is the DIP package. The board I designed uses SMD components.

Thank you again for your help.

Regards, RJM

5

Hi Tony,

Yes they are. :-). But I will check my solder joins just to be sure. But at the moment, all the effects are working well. I notice that I have two (2) LEDs out of the 100 that are defective. They might also be involved in this problem. Who knows.

If you find that someone had the same problem, please let me know.

Regards, RJM