In LEAP#231 I claimed current control was better than PWM especially for flicker-free low light levels. But is that true? In this project I test a simple 555 Timer-based PWM dimmer for comparison’s sake. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
And yes, of course it flickers. Whether that is noticable or annoying depends on the frequency.
Now perhaps some flicker might be a Very Good Thing, if the research discussed in this RadioLab episode bears up in practice. But flicker should still be something you explicitly design to have or eliminate.