I read a blog post from Particle this morning that has me asking a question. Hopefully someone here can answer them for me.
I know someone has already posted about the WS2812B chip change https://plus.google.com/+AdamHaile/posts/YpriDmfew7u
My question is: Since the PWM has increased to 2KHz (to better suit POV users according to the chip manufacturer) is that really going to help anything since the reset time has also been increased? I guess I don’t really understand the difference between the reset times and PWM.
Change notice from World Semi https://blog.particle.io/uploads/WS2812B-english.jpg
I just saw that too. I’m curious.
I have to correct myself from my comment in that post. The reset signal is sent AFTER each block of data not each pixel. So the difference isn’t really that huge. You could make POV work with these depending on how fast you refresh them and how many pixels you have. For example… if you have 100 Pixels it takes 3300 microseconds to transmit the full data block with the new pixels. and 3080 with the old. That means you can theoretically render about 300 x 100 pixels per second(but that is a locked loop). Anyway you can see that that refresh rate is SUUUPER high anyway. Even if your down to 100 renders per second you would be fine.
The PWM rate is a diferent beast. Its the rate at which each LED(red, green blue) is flickering when its ON. So if you had a really high frame rate camera recording video of 1 pixel when its on white(as an example), and your frame rate was faster than 2000frames per second, you would be able to see the LEDs flicker.
Hi, this is Aimee from WorldSemi. WS2812B protocol isn’t been changed but the RESET time changed 50us from to 280us.
@Leon_Yuhanov thank you for the reply. That makes much more sense now.
@Brian_Lewis No probs mate, thinking about it, you wouldnt even have to modify fastled just add delayMicroseconds(220) after each fastLed.show()