Arduino Uno has 4 pins that run at 960 Hz and 2 pins that run at 490 Hz.

Are those frequencies fast enough that I can change the strips that lights up the LED and create the illusion that it lights up all the time?

Or do I need higher frequencies? For example, I want to light up pin 11 first for a few milliseconds and then switch to pin 10, 6, 3 and then back to 11.


  • \$\begingroup\$ It's not very clear what you're trying to achieve. Specifically: i) why not leave the LEDs on all the time? ; ii) Are you trying to dim the LEDs by PWM? ; iii) Are you trying to make a POV display whereby a pattern is displayed on a Row of LEDs at a high rate to make a Persistent Pattern when the LEDs are moved rapidly through space? \$\endgroup\$
    – akellyirl
    Jun 25, 2014 at 13:40
  • \$\begingroup\$ I want to light up each one for a very sort time so it will consume less power and I want it to be fast so it will appear that all the LEDs light up all the time. \$\endgroup\$
    – konsalex
    Jun 25, 2014 at 14:09
  • \$\begingroup\$ OK. Then you have your answer. 490Hz is plenty fast enough to appear persistent. \$\endgroup\$
    – akellyirl
    Jun 25, 2014 at 14:51
  • \$\begingroup\$ From what I have read from people who have done such projects you will only need approximately 50-80Hz (per LED)to not notice any flickering. \$\endgroup\$
    – sherrellbc
    Jun 25, 2014 at 17:39

2 Answers 2


First, what is POV?

Second, 490Hz will be plenty fast for PWMing some LEDs. Video operates at 30fps (30Hz) and there are generally no noticeable effects.

Also, I'm pretty sure you can change the divider on those PWM pins to increase the frequency if you really wanted to.

  • \$\begingroup\$ Persistence of vision is POV. \$\endgroup\$
    – konsalex
    Jun 25, 2014 at 13:07

i did initially think 24hz is enough, but the guys here are saying more like 60-70hz creates seamless animations without tearing of images. i think its a try it and see scenario though.


are you only using 4 leds? if you look at the addressable leds (ws2811 are pretty cheap) and use the fasted h t t p : / / f a s t l e d . i o code, you can easily get some impressive results. plus the community is chatty also https://plus.google.com/u/0/communities/109127054924227823508

apologies for the spaces, my low rep is causing issues.


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