driving WS2812B (neopixels) with I2S without SCK/LRCK

RE: driving WS2812B (neopixels) with I2S without SCK/LRCK

Johnny — Wed, 15 Apr 2020 01:14:04 GMT

yes, i've seen some examples but not a plain reusable library. The i2s solution was the easiest one to implement for me.

RE: driving WS2812B (neopixels) with I2S without SCK/LRCK

mmoskal — Tue, 14 Apr 2020 23:55:31 GMT

It is possible to use PWM peripheral with double-buffer and generate the PWM data on the fly from neopixel data. I never got around to implement that though... I saw some examples, but they pre-compute neopixel data, which very memory in-efficient.

RE: driving WS2812B (neopixels) with I2S without SCK/LRCK

Johnny — Tue, 14 Apr 2020 22:03:59 GMT

the LRCK pin was not required on the nrf52832

RE: driving WS2812B (neopixels) with I2S without SCK/LRCK

Johnny — Tue, 14 Apr 2020 22:03:33 GMT

thank you! I had working code on the nrf52832 that required the SCK pin, but not the LRCK pin. The same code running on the nRF52840 does require the LRCK pin. I couldn't figure out why it wasn't working until I ran into this post.

RE: driving WS2812B (neopixels) with I2S without SCK/LRCK

Heidi — Thu, 19 Dec 2019 12:27:22 GMT

Hi!

[quote user=""]Is it possible to leave the SCK/LRCK disconnected and have the I2S still operate?[/quote]

It doesn't look like it no, since you don't get a signal when you disconnect them.

Since the creator of this sample isn't associated with Nordic, I suggest you ask him directly about any issues using it.

Best regards,

Heidi